Performances of cement-based materials incorporating new SCMs produced by the co-calcination of construction wastes with waste dolomite powder

Performances of cement-based materials incorporating new SCMs produced by the co-calcination of construction wastes with waste dolomite powder | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Performances of cement-based materials incorporating new SCMs produced by the co-calcination of construction wastes with waste dolomite powder deng chen, Ji-da Lu, Li-wu Mo, Kai-wei Liu, Ai-guo Wang, Tao Yang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5019108/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 23 Oct, 2025 Read the published version in Materials and Structures → Version 1 posted 5 You are reading this latest preprint version Abstract In this study, new types of supplementary cementitious materials (SCMs) were manufactured by the calcination of construction wastes such as engineering muck (EM) and waste brick (WB) in the presence of waste dolomite powder (WDP). The impacts of calcined dolomite-muck (CDM) and calcined dolomite-brick (CDB) on the performances of Portland cement were investigated, the reaction mechanism of CDM and CDB in pastes was also analyzed. Results showed that the mineral compositions of CDM and CDB are β-C 2 S, periclase, quartz and merwinite. The incorporations of CDM and CDB decreased obviously the hydration heat and strengths of cement-based materials at early stages. However, the blended cement mortars with 10-20% CDM and CDB obtained similar or higher strengths at later stages compared to the control mortar. This is attributed to the hydration of β-C 2 S in CDM and CDB, resulting in the pore structure densification and the lower porosity at later ages. In addition, the mortars with CDM and CDB also produced gentle expansions attributed to the hydration of periclase in CDM and CDB, which is beneficial for mitigating the shrinkage. admixtures hydration strength deformation microstructure Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 1. Introduction Over the past several decades, the manufacture of Portland cement (PC) has consumed large energy and emitted harmful greenhouse gases into atmosphere, causing severe environmental issues in the world [ 1 , 2 ]. The application of supplementary cementitious materials (SCMs) can reduce largely the production of cement clinker, thus reducing the greenhouse gas emissions and promoting the sustainable development of cement industry. Meanwhile, SCMs engage in pozzolanic or latent hydraulic reactions and contribute to strength and durability of cement materials also at higher cement clinker replacement [ 3 – 5 ]. However, the conventional SCMs such as silica fume, fly ash and slag are becoming scarce due to the adjustment of energy structure and the strict environmental policies in many regions of the word [ 6 – 8 ]. Hence, it is significant to exploit new SCMs which can still retain the excellent performance of cement materials. On the other hand, rapid urbanization often leads to massive amounts of construction activities resulting in both the consumption of raw materials and generation of construction and demolition wastes (CDW). For example, engineering muck (EM) is a typical construction waste generated in the process of exploiting large-scale underground spaces, such as subway passages and underground shopping malls. Waste bricks (WB) mainly come from the demolition of masonry structures and brick-concrete structures. It was estimated that 2.4 Bt of these wastes were generated annually in China in the past decade [ 9 ]. CDW not only take up the land but also may contain some hazardous materials, the mixture of which can cause risks to the soil environment. The utilization of CDW including EM and WB as SCMs in cement-based materials is an effective approach to recycling the wastes. Many studies have been conducted to evaluate the impacts of EM and WB on the strength and durability of cement-based materials [ 10 , 11 ]. However, the simple additions of these wastes cause a distinct reduction in the strength of blended concrete. Moreover, the mix of these wastes also weakens the durability of cement-based materials [ 12 – 14 ]. Therefore, the utilization rate of these wastes including EM and WB still remains lower compared to the use of other common SCMs. Waste dolomite powder (WDP) is a solid waste of dolomite quarries, which is often discarded in the finish processing of dolostone. In terms of environmental and economic benefits, the addition of WDP can replace a small amount of cement without weakening seriously the strength and durability of cement materials [ 15 – 17 ]. However, WDP in cement paste cured at 20°C was rarely involved in hydration reaction after 90 days [ 17 ]. It can be inferred that WDP can be only used as an inert mineral material. Therefore, the application of WDP in cement-based materials is also relatively limited compared with the utilization of other common SCMs. WDP is mainly composed of dolomite (molecular formula: CaMg(CO 3 ) 2 ) [ 18 ]. SiO 2 is the main chemical composition of EM and WB [ 19 , 20 ]. Xu [ 21 ] and Cao [ 22 ] tried to calcine dolomite with serpentine (molecular formula: Mg 6 [Si 4 O 10 ](OH) 8 ) at 950–1150°C to generate C 2 S and MgO, as shown in Eq. (1). Mg 6 [Si 4 O 10 ](OH) 8 ) + 8CaMg(CO 3 ) 2 =14MgO + 4C 2 S + 16CO 2 + 4H 2 O (1) Therefore, can these wastes also react to form new SCMs which contain C 2 S and MgO through calcining the mixtures of WDP and EM or WB? The new SCMs may be mainly based on C 2 S and MgO, C 2 S can contribute to the long-term mechanical properties, MgO can compensate for the shrinkage of cement materials. However, the effects of calcined the mixtures of WDP and EM or WB on the properties of PC have not yet been reported. In this study, the mixtures of WDP and EM, WDP and WB were calcined at high temperature, respectively. The impacts of calcined dolomite-muck (CDM) and calcined dolomite-brick (CDB) on the performances of PC were investigated, the reaction mechanism of CDM and CDB in pastes was also studied. The results of this study manifest that CDM and CDB as new SCMs may have the potential applications in cement and concrete. 2. Experimental 2.1 Raw materials The Portland cement used in this study met the Chinese national standard GB175-2007 specification with a grade of 42.5. WDP was gained from a dolomite quarry in Suzhou, Jiangsu Province (China). EM and WB were obtained from construction waste landfill field in Suzhou, Jiangsu Province (China). WDP, EM and WB were washed clean by water and dried in a drying oven at 60°C for 48 h, and then ground in a ball mill with motor speed of 48 rpm separately for 30 min to obtain fine powders, as presented in Fig. 1 . The chemical compositions of PC, WDP, EM and WB are given in Table 1 . The mineralogical compositions of WDP, EM and WB are presented in Fig. 2 , measured by X-ray diffractometer (XRD) (Rigaku Smartlab). WDP is mainly composed by dolomite, WB contains mainly quartz and EM contains albite, quartz and muscovite. The particle distribution curves of PC, WDP, EM and WB are given in Fig. 3, and the average diameters of PC, WDP, EM and WB are 12.2 µm, 6.6 µm, 7.2 µm and 11.6 µm, respectively. Table 1 Chemical compositions of PC, WDP, EM and WB (wt.%) SiO 2 Fe 2 O 3 Al 2 O 3 CaO MgO K 2 O Na 2 O Loss PC 22.24 1.34 3.36 63.54 1.23 0.62 0.43 3.13 WDP 1.07 0.35 0.47 33.45 19.15 0.09 0.06 44.29 EM 63.57 3.79 14.21 2.89 2.17 0.72 0.11 8.15 WB 69.75 2.16 14.16 1.57 1.79 0.34 0.46 2.51 2.2 Preparation of CDM and CDB To control Ca/Si mole ratio is 2:1 in the CDM and CDB, forming C 2 S, the mass ratios of WDP to EM and WDP to WB were set respectively to be 3.68:1 and 4.09:1, calculated according to the chemical compositions of WDP, EM and WB. The dried powders were mixed in a blender for 20 min to ensure the uniformity. Subsequently, water with the mass fraction of 10% was added to the powders to help molding, then the mixing continued for another 5 min. Each 50 g mixtures were compressed in a cylindrical mold to obtain the raw material cakes. Subsequently, the cakes were calcined at 900°C, 1000°C and 1100°C in an electric furnace for 1 h and 2 h, respectively, and then cooled to room temperature rapidly. MgO and CaO were firstly generated due to the decomposition of WDP during calcining process. Subsequently, CaO might react with SiO 2 contained in EM or WB to form C 2 S. Free CaO in the calcined mixtures hydrates in the first several days after casting of concrete. Great expansion generates in concrete before its sufficient mechanical strength is formed. The volume of micro pores in hardened binder paste increases to damage its microstructure [ 22 ]. Therefore, the optimum calcination temperature and holding time should be chose to promote the solid-phase reaction of CaO and SiO 2 to form C 2 S, and consuming free CaO as much as possible. To determine the optimum calcination regime, the contents of free CaO in all the calcined mixtures were tested according to Chinese national standard GB/T 176–2017. The optimum calcination temperature and holding time are 1100°C and 2 h attributed to that the content of free CaO under this calcination regime is 0.0%. Therefore, the CDM and CDB calcined at 1100°C for 2 h were produced and then ground in a ball mill. The ball mill included four specification spherical zirconia balls, with weight ratio of 10 mm: 8 mm: 5 mm: 3 mm = 1:3:6:2. The CDM and CDB were milled for 20 min with motor speed of 48 rpm, respectively. After that, the zirconia balls were separated, then the CDM and CDB powders were obtained, as presented in Fig. 4 . The XRD patterns of CDM and CDB are presented in Fig. 5 . The mainly mineral compositions of CDM and CDB are β-C 2 S, periclase, quartz and merwinite. XRD-Rietveld method [ 23 ] was also adopted for quantitative analysis of the phases in CDM and CDB. Powder patterns of the samples were analyzed by the Rietveld method as implemented in the GSAS software package by using a pseudo-Voigt peak shape function with the asymmetry correction included to obtain Rietveld Quantitative Phase Analysis (RQPA) [ 24 ]. The simplest approach to derive the phase content is the approximation that the sample is only composed of crystalline phases with known structures. However, if the sample contains amorphous phases, and/or some amounts of unaccounted crystalline phases, the analyzed weight fractions will be overestimated. In our case, ZnO used as internal standard was mixed with the test specimens. The overall content of amorphous phases and unaccounted crystalline phases is derived according to Eq. (2) [ 24 ]. \(\:\text{A}\text{C}\text{n}=\frac{1-\raisebox{1ex}{${W}_{st}$}\!\left/\:\!\raisebox{-1ex}{${R}_{st}$}\right.}{100-{W}_{st}}\) ×10 4% (2) Where ACn is the overall content of amorphous phases and unaccounted crystalline phases, W st is the weight fraction added of the internal standard which is precisely known, R st is the Rietveld refined weight fraction of the internal standard. Once the ACn content of the sample under study is known, the initial RQPA can be recalculated to yield the real sample phase contents. The contents of β-C 2 S, periclase, quartz and merwinite in CDM are 33.7%, 18.1%, 6.4% and 31.5%, and the contents of β-C 2 S, periclase, quartz and merwinite in CDB are 39.0%, 22.3%, 8.2% and 23.6%, respectively. Besides, a small amounts of amorphous phases and unaccounted crystalline phases also exist in CDM and CDB. The particle distribution curves of CDM and CDB are presented in Fig. 6, and the average diameters of CDM and CDB are 10.7 µm and 14.3 µm, respectively. 2.3 Test methods To investigated the impacts of CDM and CDB on the hydration, strength, and deformation of PC, PC was substituted separately by 0–30% CDM and CDB. Accurate weighing was done firstly and then the mixtures were mixed well. The mix proportions of cement pastes are presented in Table 2 . 2.3.1 Hydration heat The hydration heat flow curves of different cement samples were tested, after mixing homogeneously with water at a constant water-to-binder ratio of 0.5 by using an 8-channel isothermal calorimeter (Calmetrix I-cal 8000 HPC) [ 25 , 26 ]. The curing temperature is 20°C. The 72-h hydration heat values of all the specimens were recorded to investigate the hydration reaction process. 2.3.2 Strength For the strength test of all the samples, the water, binder and sand with the mass ratio of 0.5:1:3 were firstly mixed. Subsequently, the fresh cement mortars were casted into 40 × 40 × 160 mm molds. After casted, the mortars were cured for 24 h in a standard curing room (> 95% RH and 20°C). Then the mortars were moved from the molds and cured in 20°C water. After 7, 28 and 90 curing days, the flexural strengths were firstly measured, and subsequently the portions of the fractured mortars were used to test the compressive strengths. All the strengths were tested by a mechanical testing machine according to the Chinese standard GB/T 17671 − 1999. For strength measurements, the average values of replicate specimens were recorded. 2.3.3 Deformation The tests on volume deformation of the samples were performed according to literature [ 22 , 25 ]. For the deformation measurement of all the samples, the fresh cement mortars were casted into 25 × 25 × 280 mm molds. The molds were placed in a standard curing room for 24 h, and then all the mortar samples were demoulded from the molds. Subsequently, the initial length of the mortar prisms was measured and then transported in 20°C water. The length changes of the mortar specimens cured for different ages were measured, and meanwhile the average values of three replicate mortar specimens were needed. 2.3.4 Hydration products Firstly, the blended cement pastes with water-to-binder ratio of 0.5 were prepared. Subsequently, these pastes were cured in water for a certain age, then soaked in anhydrous alcohol for 24 h to stop hydration and dried in drying oven at 40°C for 1 days. Finally, the hydration assemblages of these samples were analyzed through using XRD at a scanning rate of 5 °/min from 5 to 80 ° 2θ. 2.3.5 Pore structure The pore structure of the mortar sample was measured by using low-field nuclear magnetic resonance (LF-NMR) with 0.28 ± 0.05 T magnetic field operating at a frequency of 11 MHz (MacroMR 12-025V). The samples were firstly vacuum saturated with distilled water for 24 h, then wiped with a wet towel and wrapped with three layers of seal tape to prevent water evaporation. LF-NMR can test the transverse relaxation time ( T 2 ) of free water in the capillary pores of cement-based materials [ 27 , 28 ]. The nuclear magnetic signal was proportional to the porosity of the tested sample. The proportionality factor was calibrated by the measured signal for standard samples with known water content. The longer the T 2 is, the larger the pore size is. Based on the fast exchange theory, the measured T 2 distribution was converted into pore size distribution according to Eq. ( 3 ) [ 28 , 29 ]: $$\:\frac{1}{{T}_{2}}\approx\:{\rho\:}_{2}\times\:\left(\frac{S}{V}\right)={\rho\:}_{2}\times\:\frac{2}{{r}_{p}}$$ 3 Where T 2 is the relaxation time of water in pores, ρ 2 is the T 2 surface relaxivity, r p is the pore radius, and S/V is the ratio of the pore surface area and the pore volume. Therefore, the porosity (water content ) and pore distributions of the mortar samples can be calculated with mathematical inversion technique. Table 2 Mix proportions of cement pastes (wt.%) ID Water Binder PC CDM CDB C0 50 100 0 0 CDM10 50 90 10 0 CDM20 50 80 20 0 CDM30 50 70 30 0 CDB10 50 90 0 10 CDB20 50 80 0 20 CDB30 50 70 0 30 3. Results and Discussion 3.1 Hydration heat Generally speaking, the hydration process of cement can be generally classified into four stages: (1) initial reaction period, (2) induction period, (3) acceleration period, and (4) deceleration period [ 30 , 31 ]. Figure 6 manifests the hydration heat rate variations of different samples from 0 to 72 hours. The hydration evolution tendencies of the specimens with CDM anc CDB were similar to the typical heat flow curve of reference sample (C0). Compared to the C0 sample, the additions of 10 ~ 30% CDM and CDB did not change the duration of its induction period shown in Fig. 7 (a), and caused no distinct delay of the time required to reach the hydration heat peak during the acceleration period shown in Fig. 7 (b). It indicated that CDM and CDB did not affect obviously the nature of cement hydration. Nevertheless, CDM and CDB reduced the hydration heat peak of cement, and the heat peak decreased with the increase of CDM and CDB contents [ 18 ]. Figure 8 manifests the cumulative heat release curves of the C0 sample and the samples with CDM and CDB. For all the samples, a large amount of heat was released rapidly during the first 24 h [ 25 ], and the hydration heat release gradually slowed down after 24 h. Further analysis found that the cumulative hydration heat curves of all the samples was similar in the first 6 h, indicating that the soluble substances dissolved from the C0 paste and the pastes with CDM and CDB were rapid and synchronous at early stages. However, as the hydration reaction continued (from 6 to 72 hours), the cumulative hydration heat decreased obviously with increasing CDM and CDB contents. Compared to the C0 paste, the 72-hour ultimate hydration heat values of the CDM10, CDM20, CDM30, CDB10, CDB20 and CDB30 pastes were decreased 9.5%, 18.4%, 26.1%, 8.0%, 19.8% and 26.3%, respectively. 3.2 Strength Figure 9 presents the flexural and compressive strength evolution of the C0 mortar and the mortars with CDM and CDB. In comparison to the C0 mortar, an obvious decline of the flexural and compressive strength was observed when replacing CDM and CDB at the ages of 7 days and 28 days, and that the strength decreased with increasing the CDM and CDB contents. It indicated that the incorporation of CDM and CDB had adverse impacts on the early strength of cement materials. However, the additions of CDM and CDB could promote the later strength growth. The strengths of the CDM10 and CDB10 mortars were higher than those of the C0 mortar at the ages of 90 days. Compared to the control, the 90 days flexural strengths of the CDM10 and CDB10 mortars were enhanced by 2.4% and 7.3%, the 90 days compressive strengths were enhanced by 3.7% and 8.6%, respectively. Additionally, the 90 days strengths of the mortars with 20% CDM and CDB were also very close to those of the C0 mortar. When the substitution ratio of cement was 30%, the incorporation of CDM and CDB might enhance the dilution effect and cause a certain reduction in strength. Nevertheless, a certain reduction in strength is approved owing the lower price of CDM and CDB attributed to the fact that the raw materials are construction wastes and calcination temperature is relative lower than that of cement clinker production. 3.3 Deformation Figure 10 shows the free deformation curves of the C0 mortar and the mortars with CDM and CDB. The C0 mortar emerged a certain shrinkage in 20°C water, and the ultimate shrinkage value reached − 0.0142% at the age of 90 days. Compared to the C0 mortar, the mortars with CDM and CDB exhibited a rapid expansion in early ages, and then the expansion curves flattened out in later ages. Additionally, with the increase of CDM and CDB contents, the expansion value increased gradually. The ultimate expansion values of the CDM10, CDM20, CDM30, CDB10, CDB20 and CDB30 mortars were 0.0092%, 0.0162%, 0.022%, 0.0155%, 0.0183% and 0.0282%, respectively. This indicated that expansive characteristics of CDM and CDB was close to those of ordinary MgO expansive agents as reported in the previous literature [ 32 , 33 ]. The hydration of MgO in CDM and CDB could produce a certain expansion, and compensated the shrinkage of pure cement-based materials. 3.4 Hydration products Figure 11 manifests the XRD patterns of the C0 paste and the pastes with CDM and CDB cured for 90 days. As shown in Fig. 11 , the diffraction peaks of quartz and merwinite were prominent attributed to their low reactivity in the cement hydration process. The weak diffraction peaks of β-C 2 S existed in these pastes, indicating that the remaining amounts of β-C 2 S were relative low at later ages [ 34 ]. Ettringite and portlandite as two main hydration products of cement clinkers were found obviously, meanwhile other hydration assemblages also existed. The existence of calcite might be due to a certain amount of limestone powder incorporated into PC and the slight carbonation of these pastes. The existence of monocarboaluminate might be due to the reaction of calcite and Al phases in these pastes [ 35 , 36 ]. Additionally, obvious diffraction peaks of brucite were also observed in the pastes with CDM and CDB due to the hydration of periclase in CDM and CDB. The brucite contents of these pastes cured for 90 days are given in Table 3 quantitatively obtained by XRD Rietveld analysis. For the C0 paste, a slight amount of brucite was generated attributed to the fact that PC contained a minuscule amount of MgO. However, the generation of small amounts of brucite could not compensate the shrinkage of the C0 paste effectively. For the pastes with CDM and CDB, the contents of brucite increased with the increase of the CDM and CDB contents. This is explained by the fact that the hydration of MgO contained in CDM and CDB facilitates the generation of brucite, then promoting the expansion of the mortars. Table 3 The contents of brucite in cement pastes cured for 90 days (wt.%) Sample C0 CDM10 CDM20 CDM30 CDB10 CDB20 CDB30 1.9 5.7 6.4 6.9 6.3 6.5 7.1 3.5 Pore structure To analyze the impacts of CDM and CDB on the microstructure of cement materials, the pore structure of all the 90-days samples were measured by LF-NMR. Figure 12 manifests the pore size distributions of all the specimens, the pores of all the specimens ranged from 0.003 to 100 µm. According to the effect of the pores with different diameters on the properties of cementitious materials, the pore > 0.1 µm is definitely harmful [ 5 ]. Compared with the C0 mortar, the CDM20, CDM30, CDB20 and CDB30 mortars had more pores with the diameter of 0.003-0.1 µm, as shown in Fig. 12 . However, the addition of 10% CDM and CDB reduced the pore volume of the pore with the diameter less than 0.1 µm. Additionally, the contents of > 0.1 µm pores were also decreased with the additions of 10–30% CDM and CDB. Table 4 shows the porosities of all the mortar samples. The total porosities of the CDM10 and CDB10 mortars were obvious lower than that of the C0 mortar. The total porosities of the CDM20 and CDB20 mortars were only slight higher than that of the C0 mortar. Therefore, the mortars with 10–20% CDM and CDB still exhibited excellent mechanical properties. Table 4 Porosities of cement mortars cured for 90 days (vol.%) Sample C0 CDM10 CDM20 CDM30 CDB10 CDB20 CDB30 Porosity 13.66 13.12 14.15 15.09 12.84 13.97 15.12 3.6 Discussion It was demonstrated that the additions of CDM and CDB notably reduced the hydration heat release of cement paste, indicating that CDM and CDB was positive to avoid the cracks caused by temperature shrinkage in cement-based materials. The decrease in the hydration heat release may be attributed to the lower content of cement clinker in the pastes containing CDM and CDB compared to the C0 paste. Additionally, the early-age hydration reactivity of quartz, merwinite, and β-C 2 S in CDM and CDB exhibited relatively lower than the cement clinker. The additions of CDM and CDB also reduced the early-age strengths of PC mortars, mainly due to the formation of lower proportions of hydration products in the paste. However, CDM and CDB increased the strengths at later stages. This observation showed that the incorporations of CDM and CDB had obvious positive effects on the long-term properties. This may be explained by that the hydration of β-C 2 S in CDM and CDB produced more hydration products at later stages, resulting in the pore structure densification, thereby contributing to the later strength development [ 37 ]. It should be noticed whether or not the hydration of MgO in CDM and CDB also influenced the strength. The contents of MgO in CDM and CDB were 18.1% and 22.3%, respectively, and their proportions in the mixed cements ranged from 10–30%, resulting in MgO percentages in the mixed cements of 1.8–6.6%. Previous studies proved that ordinary MgO expansive agents do not, or only slightly decrease the strengths of cement and concrete, when the amount of MgO is less than 6% [ 22 , 38 – 39 ]. Thus, the hydration of MgO in CDM and CDB should not be recognized as the main factor controlling the strengths of mortars. On the other hand, with sufficient supply of water, the CDM and CDB addition promoted the formation of brucite, which was generated to induce expansion for compensating the shrinkage of cement materials. Moreover, the brucite contents increased with the increase of CDM and CDB contents, as shown in Table 3 , thus causing an obvious increase in expansion. In addition, the ultimate expansion of all the cement mortars with 10–30% CDM and CDB did not exceed 0.06%, which is the maximum expansion of MgO concrete without compromising its soundness according to DL/T 5296 − 2013. Accordingly, the incorporation of appropriate addition of CDM and CDB could produce the mixed cements with low hydration heat, non-shrinkage and high strength in comparison to PC, meanwhile also promoting the application of WDP, EM and WB in cement materials. 4. Conclusions Producing new SCMs (CDM and CDB) by calcining the mixtures of WDP and EM, WDP and WB in 1100 °C is feasible. The major mineral compositions of CDM and CDB are β-C 2 S, periclase, quartz and merwinite. The incorporations of CDM and CDB did not affect obviously the hydration process of Portland cement, but decreased the hydration heat. This is positive to avoid the cracks caused by temperature shrinkage in cement-based materials. Replacement of PC with 10-30% CDM and CDB resulted in strength decrease at early stages. However, the blended cement mortars with 10-20% CDM and CDB gained equivalent or higher strengths at later stages in comparison to the reference C0 mortar. This is mainly related to the pore structure densification and the reduced porosity attributed to the hydration of β-C 2 S in CDM and CDB. Additionally, the incorporations of CDM and CDB produced gentle expansions compared to the reference C0 mortar due to the generation of brucite attributed to the hydration of periclase in CDM and CDB. Moreover, the brucite contents increased with the increase of CDM and CDB contents, then causing an obvious increase in expansion. Declarations Acknowledgements This work is supported by the National Natural Science Foundation of China (52208279), Natural Science Foundation of Jiangsu Province of China (BK20220639), Natural Science Foundation of the Jiangsu Higher Education Institution of China (20KJB560007) and Postgraduate Research & Practice Innovation Program of Jiangsu Province (SJCX24_1931). Compliance with ehical standards Conflict of interest The authors declared that they have no conflict of interest in the submission of this manuscript, and manuscript is approved by all authors for publication. I would like to declare on behalf of my co-authors that the work described was original research that has not been published previously, and not under consideration for publication elsewhere, in whole or in part. All the authors listed have approved the manuscript that is enclosed. References Jang JG, Kim GM, Kim HJ, Lee HK (2016) Review on recent advances in CO 2 utilization and sequestration technologies in cement-based materials. Construction and Building Materials 127:762-773. Brito JD, Kurda R (2021) The past and future of sustainable concrete: a critical review and new strategies on cement-based materials. Journal of Cleaner Production 281:123558. Aprianti E (2017) A huge number of artificial waste material can be supplementary cementitious material (SCM) for concrete production-a review part II. Journal of Cleaner Production 142: 4178-4194. Scrivener KL, Martirena F, Bishnoi S, Maity S (2018) Calcined clay limestone cements (LC3). Cement and Concrete Research 114:49-56. He ZH, Du SG, Chen D (2018) Microstructure of ultra high performance concrete containing lithium slag. Journal of Hazardous Materials 353:35-43. Samad S, Shah A (2017) Role of binary cement including supplementary cementitious material (SCM), in production of environmentally sustainable concrete: A critical review. International Journal of Sustainable Built Environment 6(2):663-674. Mohammadi A, Ramezanianpour AM (2023) Investigating the environmental and economic impacts of using supplementary cementitious materials (SCMs) using the life cycle approach. Journal of Building Engineering 79:107934. Juenger MCG, Snellings R, Bernal SA (2019) Supplementary cementitious materials: New sources, characterization, and performance insights. Cement and Concrete Research 122: 257-273. Duan HB, Miller TR, Liu G, Tam VWY (2019) Construction debris becomes growing concern of growing cities. Waste Management 83:1-5. Gao WB, Zhang HG, Ren Q, Zhong YJ, Jiang ZW (2023) A low-carbon approach to recycling engineering muck to produce non-sintering lightweight aggregates: Physical properties, microstructure, reaction mechansim, and life cycle assessment. Journal of Cleaner Production 385:135650. Alcharchafche MAS, Al-mashhadani MM, Aygörmez Y (2022) Investigation of mechanical and durability properties of brick powder-added white cement composites with three different fibers. Construction and Building Materials 347:128548. Jiao N, Wan X, Ding JW, Zhang XR, Xue CR (2024) Mechanical properties and microstructure of lime-treated shield tunnel muck improved with carbide slag and soda residue. Construction and Building Materials 428:136419. Zhang HY, Ma JY, Chen Z, Wu B (2024) Effect and mechanism of recycled clay brick powder on compressive strength of different types of concretes. Journal of Building Engineering 94:109983. Zeng H, Li Y (2024) Effect of waste stone powder on compressive strength and pore structure of concrete in extreme low temperature and complex environment. Journal of Building Engineering 95:110108. Chen D, Yang T, Liu KW, Wang AG (2021) Influence of dolomite powder fineness on hydration of blended cements at different curing temperatures. Revista Română de Materiale / Romanian Journal of Materials 51(3):395-404. Zhang X, Luo Y, Yao W (2022) Effects of dolomite powder on the properties of C30 and C50 concretes. Fullerenes, Nanotubes and Carbon Nanostructures 30(9):896-905. Xu JT, Lu DY, Zhang SH, Xu ZZ, Hooton RD (2021) Reaction mechanism of dolomite powder in Portland-dolomite cement. Construction and Building Materials 270:121375. Hu HB, Yao W, Wei YQ (2023) Recycling waste dolomite powder in cement paste: early hydration process, microscale characteristics, and life-cycle assessment. Science of the Total Environment 902:166008. Wu HX, Gao JM, Liu C, Guo ZH, Luo X (2024) Reusing waste clay brick powder for low-carbon cement concrete and alkali-activated concrete: A critical review. Journal of Cleaner Production 449:141755. Lei JS, Yang Y, Chen XH (2024) Mechanics and permeability properties of ecological concrete mixed with recycled engineering muck particles. Journal of Building Engineering 91: 109560. Xu LL, Deng M (2005) Dolomite used as raw materials to produce MgO-based expansive agent. Cement and Concrete Research 35(8):1480-1485. Cao FZ, Liu Y, Yan PY (2021) Properties and mechanism of the compound MgO expansive agent (CMEA) produced by calcining the mixture of dolomite and serpentine tailings. Construction and Building Materials 277:122331. Scrivener KL, Füllmann T, Gallucci E, Walenta G, Bermejo E (2004) Quantitative study of Portland cement hydration by X-ray diffraction/Rietveld analysis and independent methods. Cement and Concrete Research 34(9):1541-1547. Álvarez-Pinazo G, Cuesta A, García-Maté M, Santacruz I, Losilla ER, De la Torre AG, León-Reina L, Aranda MAG (2012) Rietveld quantitative phase analysis of Yeelimite-containing cements. Cement and Concrete Research 42:960-971. Chen D, Mo LW, Wang AG, Liu KW, Zhang SP, Yang T (2023) The hydration, strength and deformation of Portland composite cements containing light-burnt dolomite and metakaolin. Advances in Cement Research 35(3):135-143. Guo H, Wang Z, Zhao X, Liu J, Ji X, Shi W (2022) Effects of dolomite powder on properties of environment-friendly cement asphalt emulsion composites. Journal of Cleaner Production 369:133321. Liu H, Sun ZP, Yang JB, Ji YL (2021) A novel method for semi-quantitative analysis of hydration degree of cement by 1 H low-field NMR. Cement and Concrete Research 141, 106329. Chen D, Mo LW, Liu KW, Wang AG, Zhang SP, Di QF, Yan J (2022) Hydration and pore structure evolution of white cement paste at early age based on 1 H low-field nuclear magnetic resonance. Revista Română de Materiale / Romanian Journal of Materials 52(2):203-208. Jiang ZL, Pan YJ, Lu JF, Wang YC (2022) Pore structure characterization of cement paste by different experimental methods and its influence on permeability evaluation. Cement and Concrete Research 159:106892. Scrivener K, Ouzia A, Juilland P, Mohamed AK (2019) Advances in understanding cement hydration mechanisms. Cement and Concrete Research 124:105823. Briki Y, Zajac M, Haha MB, Scrivener K (2021) Impact of limestone fineness on cement hydration at early age. Cement and Concrete Research 147:106515. Zhang J (2022) Recent advance of MgO expansive agent in cement and concrete. Journal of Building Engineering 45:103633. Cao FZ, Yan PY (2019) The influence of the hydration procedure of MgO expansive agent on the expansive behavior of shrinkage-compensating mortar. Construction and Building Materials 202:162-168. Krishnan S, Zunino F, Bishnoi S, Scrivener K (2023) Characterisation and hydration kinetics of β-C 2 S synthesised with K 2 SO 4 as dopant. Cement and Concrete Research 167:107119. Ji GX, Chi HH, Sun KK, Peng XQ, Cai YM (2024) Effect of limestone waste on the hydration and microstructural properties of cement-based materials. Construction and Building Materials 443:137784. Tang J, Wei SF, Li WF, Ma SH, Ji PH, Shen XD (2019) Synergistic effect of metakaolin and limestone on the hydration properties of Portland cement. Construction and Building Materials 223:177-184. Zhang JT, Zhang WS, Ye JY, Ren XH, Liu L, Shen WG (2021) Influence of alkaline carbonates on the hydration characteristics of β-C 2 S. Construction and Building Materials, 296:123661. Mo LW, Liu M, Tabbaa AA, Deng M, Lau WY (2015) Deformation and mechanical properties of quaternary blended cements containing ground granulated blast furnace slag, fly ash and magnesia. Cement and Concrete Research 71:7-13. Sherir MAA, Hossain KMA, Lachemi M (2016) Self-healing and expansion characteristics of cementitious composites with high volume fly ash and MgO-type expansive agent. Construction and Building Materials 127:80-92. Cite Share Download PDF Status: Published Journal Publication published 23 Oct, 2025 Read the published version in Materials and Structures → Version 1 posted Reviewers agreed at journal 20 Dec, 2024 Reviewers invited by journal 13 Dec, 2024 Editor invited by journal 27 Nov, 2024 Editor assigned by journal 26 Nov, 2024 First submitted to journal 25 Nov, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5019108","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":389985345,"identity":"d1a64aca-b4a0-4ccd-8ff4-245bf61fd348","order_by":0,"name":"deng chen","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIiWNgGAWjYDCCA0D8ocJGTp69+eCDhIoa4rQwzjiTZmzYcyzZ4MGZY8RpYeZtO5zYcCNHTfJhCzNhHXzHew+/4G1jNmZsyGGrSGxgY+Bv707Aq0XyzLk0C4lzbHLsDGeP3UjcIcMgcebsBrxaDG7kmBkYlPEYMzb2pd1IPMPGYCCRS0DL/TdmBglsEokNh3nMChLbmInQcoPH+MGBNoPEhmM8ZgxEaZE8k2PG2HAmARjIbMkSCWeO8RD0C9/xM8af/1T8l5OXf3zw44+KGjn+9l78WoCATQKZx0NIOQgwfyBG1SgYBaNgFIxgAABHwVF/dytReAAAAABJRU5ErkJggg==","orcid":"","institution":"Suzhou University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"deng","middleName":"","lastName":"chen","suffix":""},{"id":389985346,"identity":"a3a2fe0c-4260-487c-b1ab-14fdafede2f6","order_by":1,"name":"Ji-da Lu","email":"","orcid":"","institution":"Suzhou University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Ji-da","middleName":"","lastName":"Lu","suffix":""},{"id":389985347,"identity":"89e3083d-45d5-4434-a617-e2459363f2d2","order_by":2,"name":"Li-wu Mo","email":"","orcid":"","institution":"Nanjing Tech University","correspondingAuthor":false,"prefix":"","firstName":"Li-wu","middleName":"","lastName":"Mo","suffix":""},{"id":389985348,"identity":"181b5462-a0ef-4830-b01d-553657e97978","order_by":3,"name":"Kai-wei Liu","email":"","orcid":"","institution":"Anhui Jianzhu University","correspondingAuthor":false,"prefix":"","firstName":"Kai-wei","middleName":"","lastName":"Liu","suffix":""},{"id":389985349,"identity":"1a27744a-cc78-44d8-b956-74064b4ba40f","order_by":4,"name":"Ai-guo Wang","email":"","orcid":"","institution":"Anhui Jianzhu University","correspondingAuthor":false,"prefix":"","firstName":"Ai-guo","middleName":"","lastName":"Wang","suffix":""},{"id":389985350,"identity":"ef06dc8e-33ab-4391-993e-9d179f0023a7","order_by":5,"name":"Tao Yang","email":"","orcid":"","institution":"Yancheng Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Tao","middleName":"","lastName":"Yang","suffix":""}],"badges":[],"createdAt":"2024-09-02 14:21:54","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5019108/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5019108/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1617/s11527-025-02843-2","type":"published","date":"2025-10-23T16:17:01+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":71549100,"identity":"04059373-435e-4ee3-93df-b4d71469fb58","added_by":"auto","created_at":"2024-12-16 15:32:34","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":490814,"visible":true,"origin":"","legend":"\u003cp\u003eThe morphology pictures of WDP, EM and WB\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/2cdf04f4efdd8f349f71c4a9.png"},{"id":71549101,"identity":"6b0bb264-af34-4a97-9294-e8dfabcb46a7","added_by":"auto","created_at":"2024-12-16 15:32:34","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":100164,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns of WDP, EM and WB\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/599e24264504ed259eb52c70.png"},{"id":71550931,"identity":"4a34e52a-98b6-4087-8a78-ee7caf3e926c","added_by":"auto","created_at":"2024-12-16 15:48:35","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":95441,"visible":true,"origin":"","legend":"\u003cp\u003eParticle size distributions of PC, WDP, EM and WB\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/3df6e1081394842dc1906f16.png"},{"id":71549102,"identity":"97ef0e1c-f79a-4b76-aefb-523c87e16791","added_by":"auto","created_at":"2024-12-16 15:32:34","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":342905,"visible":true,"origin":"","legend":"\u003cp\u003eThe morphology pictures of CDM and CDB\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/c407c6bdaaf083f67970d56e.png"},{"id":71550458,"identity":"5241da06-0268-4c89-a028-e1f16e3660ca","added_by":"auto","created_at":"2024-12-16 15:40:34","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":96035,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns of CDM and CDB\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/ba8aa82c6bc7381fa6169db3.png"},{"id":71550459,"identity":"889b5c79-564a-412a-b7a5-40b1f2cdb92d","added_by":"auto","created_at":"2024-12-16 15:40:35","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":58889,"visible":true,"origin":"","legend":"\u003cp\u003eParticle size distributions of CDM and CDB\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/69ca6176760e0d2ba3ff0c80.png"},{"id":71550461,"identity":"48803205-b870-4dbb-bf4a-16e78fde6da6","added_by":"auto","created_at":"2024-12-16 15:40:35","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":154138,"visible":true,"origin":"","legend":"\u003cp\u003eHydration heat rate curves of cements\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/d1955b75a87fe3b22f5cf56d.png"},{"id":71549147,"identity":"68ee2d50-5b9c-4301-adec-1ae1ea504434","added_by":"auto","created_at":"2024-12-16 15:32:40","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":110607,"visible":true,"origin":"","legend":"\u003cp\u003eCumulative hydration heat curves of cements\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/256a6f9fe3f914a343433224.png"},{"id":71549109,"identity":"f79ef30b-9f65-4bc1-84e3-913a4aa04e54","added_by":"auto","created_at":"2024-12-16 15:32:35","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":174801,"visible":true,"origin":"","legend":"\u003cp\u003eMechanical properties of cement mortars\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/d2b89be3b905386f8e57ba0c.png"},{"id":71549117,"identity":"fd7c5059-be40-480d-b562-69ec1ad5a399","added_by":"auto","created_at":"2024-12-16 15:32:35","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":169317,"visible":true,"origin":"","legend":"\u003cp\u003eDeformation of cement mortars cured in 20 °C water\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/a11cb31dede1fff59d3bf5c5.png"},{"id":71549111,"identity":"d7473359-61f3-46ae-8238-93f889a36697","added_by":"auto","created_at":"2024-12-16 15:32:35","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":206107,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns of cement pastes cured for 90 days\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/9223482193a43bb799310654.png"},{"id":71550932,"identity":"fc8f1aa7-97a9-4adb-9c59-2bd65b62d54a","added_by":"auto","created_at":"2024-12-16 15:48:35","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":153592,"visible":true,"origin":"","legend":"\u003cp\u003ePore size distributions of cement mortars cured for 90 days\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/2f0673fef2561025f5b142c3.png"},{"id":94490652,"identity":"e67b3df1-ec5e-420f-a881-c021631c8a48","added_by":"auto","created_at":"2025-10-27 17:13:30","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2972035,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5019108/v1/1c9c3721-f5c1-4dfd-812d-0fed618455b7.pdf"}],"financialInterests":"","formattedTitle":"Performances of cement-based materials incorporating new SCMs produced by the co-calcination of construction wastes with waste dolomite powder","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eOver the past several decades, the manufacture of Portland cement (PC) has consumed large energy and emitted harmful greenhouse gases into atmosphere, causing severe environmental issues in the world [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The application of supplementary cementitious materials (SCMs) can reduce largely the production of cement clinker, thus reducing the greenhouse gas emissions and promoting the sustainable development of cement industry. Meanwhile, SCMs engage in pozzolanic or latent hydraulic reactions and contribute to strength and durability of cement materials also at higher cement clinker replacement [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, the conventional SCMs such as silica fume, fly ash and slag are becoming scarce due to the adjustment of energy structure and the strict environmental policies in many regions of the word [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Hence, it is significant to exploit new SCMs which can still retain the excellent performance of cement materials.\u003c/p\u003e \u003cp\u003eOn the other hand, rapid urbanization often leads to massive amounts of construction activities resulting in both the consumption of raw materials and generation of construction and demolition wastes (CDW). For example, engineering muck (EM) is a typical construction waste generated in the process of exploiting large-scale underground spaces, such as subway passages and underground shopping malls. Waste bricks (WB) mainly come from the demolition of masonry structures and brick-concrete structures. It was estimated that 2.4 Bt of these wastes were generated annually in China in the past decade [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. CDW not only take up the land but also may contain some hazardous materials, the mixture of which can cause risks to the soil environment. The utilization of CDW including EM and WB as SCMs in cement-based materials is an effective approach to recycling the wastes. Many studies have been conducted to evaluate the impacts of EM and WB on the strength and durability of cement-based materials [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, the simple additions of these wastes cause a distinct reduction in the strength of blended concrete. Moreover, the mix of these wastes also weakens the durability of cement-based materials [\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Therefore, the utilization rate of these wastes including EM and WB still remains lower compared to the use of other common SCMs.\u003c/p\u003e \u003cp\u003eWaste dolomite powder (WDP) is a solid waste of dolomite quarries, which is often discarded in the finish processing of dolostone. In terms of environmental and economic benefits, the addition of WDP can replace a small amount of cement without weakening seriously the strength and durability of cement materials [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. However, WDP in cement paste cured at 20\u0026deg;C was rarely involved in hydration reaction after 90 days [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. It can be inferred that WDP can be only used as an inert mineral material. Therefore, the application of WDP in cement-based materials is also relatively limited compared with the utilization of other common SCMs. WDP is mainly composed of dolomite (molecular formula: CaMg(CO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e) [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. SiO\u003csub\u003e2\u003c/sub\u003e is the main chemical composition of EM and WB [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Xu [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] and Cao [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] tried to calcine dolomite with serpentine (molecular formula: Mg\u003csub\u003e6\u003c/sub\u003e[Si\u003csub\u003e4\u003c/sub\u003eO\u003csub\u003e10\u003c/sub\u003e](OH)\u003csub\u003e8\u003c/sub\u003e) at 950\u0026ndash;1150\u0026deg;C to generate C\u003csub\u003e2\u003c/sub\u003eS and MgO, as shown in Eq.\u0026nbsp;(1).\u003c/p\u003e \u003cp\u003eMg\u003csub\u003e6\u003c/sub\u003e[Si\u003csub\u003e4\u003c/sub\u003eO\u003csub\u003e10\u003c/sub\u003e](OH)\u003csub\u003e8\u003c/sub\u003e)\u0026thinsp;+\u0026thinsp;8CaMg(CO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e =14MgO\u0026thinsp;+\u0026thinsp;4C\u003csub\u003e2\u003c/sub\u003eS\u0026thinsp;+\u0026thinsp;16CO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;4H\u003csub\u003e2\u003c/sub\u003eO (1)\u003c/p\u003e \u003cp\u003eTherefore, can these wastes also react to form new SCMs which contain C\u003csub\u003e2\u003c/sub\u003eS and MgO through calcining the mixtures of WDP and EM or WB? The new SCMs may be mainly based on C\u003csub\u003e2\u003c/sub\u003eS and MgO, C\u003csub\u003e2\u003c/sub\u003eS can contribute to the long-term mechanical properties, MgO can compensate for the shrinkage of cement materials. However, the effects of calcined the mixtures of WDP and EM or WB on the properties of PC have not yet been reported.\u003c/p\u003e \u003cp\u003eIn this study, the mixtures of WDP and EM, WDP and WB were calcined at high temperature, respectively. The impacts of calcined dolomite-muck (CDM) and calcined dolomite-brick (CDB) on the performances of PC were investigated, the reaction mechanism of CDM and CDB in pastes was also studied. The results of this study manifest that CDM and CDB as new SCMs may have the potential applications in cement and concrete.\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003e2.1 Raw materials\u003c/h2\u003e\n \u003cp\u003eThe Portland cement used in this study met the Chinese national standard GB175-2007 specification with a grade of 42.5. WDP was gained from a dolomite quarry in Suzhou, Jiangsu Province (China). EM and WB were obtained from construction waste landfill field in Suzhou, Jiangsu Province (China). WDP, EM and WB were washed clean by water and dried in a drying oven at 60\u0026deg;C for 48 h, and then ground in a ball mill with motor speed of 48 rpm separately for 30 min to obtain fine powders, as presented in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. The chemical compositions of PC, WDP, EM and WB are given in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. The mineralogical compositions of WDP, EM and WB are presented in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e, measured by X-ray diffractometer (XRD) (Rigaku Smartlab). WDP is mainly composed by dolomite, WB contains mainly quartz and EM contains albite, quartz and muscovite. The particle distribution curves of PC, WDP, EM and WB are given in Fig. 3, and the average diameters of PC, WDP, EM and WB are 12.2 \u0026micro;m, 6.6 \u0026micro;m, 7.2 \u0026micro;m and 11.6 \u0026micro;m, respectively.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eChemical compositions of PC, WDP, EM and WB (wt.%)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"9\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eFe\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCaO\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMgO\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eK\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNa\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLoss\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e63.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.13\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWDP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e33.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e19.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e44.29\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eEM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e63.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8.15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e69.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e14.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.51\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003e2.2 Preparation of CDM and CDB\u003c/h2\u003e\n \u003cp\u003eTo control Ca/Si mole ratio is 2:1 in the CDM and CDB, forming C\u003csub\u003e2\u003c/sub\u003eS, the mass ratios of WDP to EM and WDP to WB were set respectively to be 3.68:1 and 4.09:1, calculated according to the chemical compositions of WDP, EM and WB. The dried powders were mixed in a blender for 20 min to ensure the uniformity. Subsequently, water with the mass fraction of 10% was added to the powders to help molding, then the mixing continued for another 5 min. Each 50 g mixtures were compressed in a cylindrical mold to obtain the raw material cakes. Subsequently, the cakes were calcined at 900\u0026deg;C, 1000\u0026deg;C and 1100\u0026deg;C in an electric furnace for 1 h and 2 h, respectively, and then cooled to room temperature rapidly. MgO and CaO were firstly generated due to the decomposition of WDP during calcining process. Subsequently, CaO might react with SiO\u003csub\u003e2\u003c/sub\u003e contained in EM or WB to form C\u003csub\u003e2\u003c/sub\u003eS. Free CaO in the calcined mixtures hydrates in the first several days after casting of concrete. Great expansion generates in concrete before its sufficient mechanical strength is formed. The volume of micro pores in hardened binder paste increases to damage its microstructure [\u003cspan class=\"CitationRef\"\u003e22\u003c/span\u003e]. Therefore, the optimum calcination temperature and holding time should be chose to promote the solid-phase reaction of CaO and SiO\u003csub\u003e2\u003c/sub\u003e to form C\u003csub\u003e2\u003c/sub\u003eS, and consuming free CaO as much as possible. To determine the optimum calcination regime, the contents of free CaO in all the calcined mixtures were tested according to Chinese national standard GB/T 176\u0026ndash;2017. The optimum calcination temperature and holding time are 1100\u0026deg;C and 2 h attributed to that the content of free CaO under this calcination regime is 0.0%. Therefore, the CDM and CDB calcined at 1100\u0026deg;C for 2 h were produced and then ground in a ball mill. The ball mill included four specification spherical zirconia balls, with weight ratio of 10 mm: 8 mm: 5 mm: 3 mm\u0026thinsp;=\u0026thinsp;1:3:6:2. The CDM and CDB were milled for 20 min with motor speed of 48 rpm, respectively. After that, the zirconia balls were separated, then the CDM and CDB powders were obtained, as presented in Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003eThe XRD patterns of CDM and CDB are presented in Fig. \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e. The mainly mineral compositions of CDM and CDB are \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS, periclase, quartz and merwinite. XRD-Rietveld method [\u003cspan class=\"CitationRef\"\u003e23\u003c/span\u003e] was also adopted for quantitative analysis of the phases in CDM and CDB. Powder patterns of the samples were analyzed by the Rietveld method as implemented in the GSAS software package by using a pseudo-Voigt peak shape function with the asymmetry correction included to obtain Rietveld Quantitative Phase Analysis (RQPA) [\u003cspan class=\"CitationRef\"\u003e24\u003c/span\u003e]. The simplest approach to derive the phase content is the approximation that the sample is only composed of crystalline phases with known structures. However, if the sample contains amorphous phases, and/or some amounts of unaccounted crystalline phases, the analyzed weight fractions will be overestimated. In our case, ZnO used as internal standard was mixed with the test specimens. The overall content of amorphous phases and unaccounted crystalline phases is derived according to Eq.\u0026nbsp;(2) [\u003cspan class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u0026nbsp;\u003cspan class=\"mathinline\"\u003e\\(\\:\\text{A}\\text{C}\\text{n}=\\frac{1-\\raisebox{1ex}{${W}_{st}$}\\!\\left/\\:\\!\\raisebox{-1ex}{${R}_{st}$}\\right.}{100-{W}_{st}}\\)\u003c/span\u003e\u0026nbsp;\u003c/span\u003e\u0026times;10\u003csup\u003e4%\u003c/sup\u003e (2)\u003c/p\u003e\n \u003cp\u003eWhere \u003cem\u003eACn\u003c/em\u003e is the overall content of amorphous phases and unaccounted crystalline phases, \u003cem\u003eW\u003c/em\u003e\u003csub\u003e\u003cem\u003est\u003c/em\u003e\u003c/sub\u003e is the weight fraction added of the internal standard which is precisely known, \u003cem\u003eR\u003c/em\u003e\u003csub\u003e\u003cem\u003est\u003c/em\u003e\u003c/sub\u003e is the Rietveld refined weight fraction of the internal standard. Once the \u003cem\u003eACn\u003c/em\u003e content of the sample under study is known, the initial RQPA can be recalculated to yield the real sample phase contents. The contents of \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS, periclase, quartz and merwinite in CDM are 33.7%, 18.1%, 6.4% and 31.5%, and the contents of \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS, periclase, quartz and merwinite in CDB are 39.0%, 22.3%, 8.2% and 23.6%, respectively. Besides, a small amounts of amorphous phases and unaccounted crystalline phases also exist in CDM and CDB. The particle distribution curves of CDM and CDB are presented in Fig. 6, and the average diameters of CDM and CDB are 10.7 \u0026micro;m and 14.3 \u0026micro;m, respectively.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003e2.3 Test methods\u003c/h2\u003e\n \u003cp\u003eTo investigated the impacts of CDM and CDB on the hydration, strength, and deformation of PC, PC was substituted separately by 0\u0026ndash;30% CDM and CDB. Accurate weighing was done firstly and then the mixtures were mixed well. The mix proportions of cement pastes are presented in Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\n \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\n \u003ch2\u003e2.3.1 Hydration heat\u003c/h2\u003e\n \u003cp\u003eThe hydration heat flow curves of different cement samples were tested, after mixing homogeneously with water at a constant water-to-binder ratio of 0.5 by using an 8-channel isothermal calorimeter (Calmetrix I-cal 8000 HPC) [\u003cspan class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e]. The curing temperature is 20\u0026deg;C. The 72-h hydration heat values of all the specimens were recorded to investigate the hydration reaction process.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\n \u003ch2\u003e2.3.2 Strength\u003c/h2\u003e\n \u003cp\u003eFor the strength test of all the samples, the water, binder and sand with the mass ratio of 0.5:1:3 were firstly mixed. Subsequently, the fresh cement mortars were casted into 40 \u0026times; 40 \u0026times; 160 mm molds. After casted, the mortars were cured for 24 h in a standard curing room (\u0026gt;\u0026thinsp;95% RH and 20\u0026deg;C). Then the mortars were moved from the molds and cured in 20\u0026deg;C water. After 7, 28 and 90 curing days, the flexural strengths were firstly measured, and subsequently the portions of the fractured mortars were used to test the compressive strengths. All the strengths were tested by a mechanical testing machine according to the Chinese standard GB/T 17671\u0026thinsp;\u0026minus;\u0026thinsp;1999. For strength measurements, the average values of replicate specimens were recorded.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\n \u003ch2\u003e2.3.3 Deformation\u003c/h2\u003e\n \u003cp\u003eThe tests on volume deformation of the samples were performed according to literature [\u003cspan class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e25\u003c/span\u003e]. For the deformation measurement of all the samples, the fresh cement mortars were casted into 25 \u0026times; 25 \u0026times; 280 mm molds. The molds were placed in a standard curing room for 24 h, and then all the mortar samples were demoulded from the molds. Subsequently, the initial length of the mortar prisms was measured and then transported in 20\u0026deg;C water. The length changes of the mortar specimens cured for different ages were measured, and meanwhile the average values of three replicate mortar specimens were needed.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\n \u003ch2\u003e2.3.4 Hydration products\u003c/h2\u003e\n \u003cp\u003eFirstly, the blended cement pastes with water-to-binder ratio of 0.5 were prepared. Subsequently, these pastes were cured in water for a certain age, then soaked in anhydrous alcohol for 24 h to stop hydration and dried in drying oven at 40\u0026deg;C for 1 days. Finally, the hydration assemblages of these samples were analyzed through using XRD at a scanning rate of 5 \u0026deg;/min from 5 to 80 \u0026deg; 2\u0026theta;.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e\n \u003ch2\u003e2.3.5 Pore structure\u003c/h2\u003e\n \u003cp\u003eThe pore structure of the mortar sample was measured by using low-field nuclear magnetic resonance (LF-NMR) with 0.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 T magnetic field operating at a frequency of 11 MHz (MacroMR 12-025V). The samples were firstly vacuum saturated with distilled water for 24 h, then wiped with a wet towel and wrapped with three layers of seal tape to prevent water evaporation. LF-NMR can test the transverse relaxation time (\u003cem\u003eT\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sub\u003e) of free water in the capillary pores of cement-based materials [\u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e]. The nuclear magnetic signal was proportional to the porosity of the tested sample. The proportionality factor was calibrated by the measured signal for standard samples with known water content. The longer the \u003cem\u003eT\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sub\u003e is, the larger the pore size is. Based on the fast exchange theory, the measured \u003cem\u003eT\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sub\u003e distribution was converted into pore size distribution according to Eq. (\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e) [\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e]:\u003c/p\u003e\n \u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e$$\\:\\frac{1}{{T}_{2}}\\approx\\:{\\rho\\:}_{2}\\times\\:\\left(\\frac{S}{V}\\right)={\\rho\\:}_{2}\\times\\:\\frac{2}{{r}_{p}}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003eWhere \u003cem\u003eT\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sub\u003e is the relaxation time of water in pores, \u003cem\u003e\u0026rho;\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sub\u003e is the \u003cem\u003eT\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sub\u003e surface relaxivity, \u003cem\u003er\u003c/em\u003e\u003csub\u003e\u003cem\u003ep\u003c/em\u003e\u003c/sub\u003e is the pore radius, and \u003cem\u003eS/V\u003c/em\u003e is the ratio of the pore surface area and the pore volume. Therefore, the porosity (water content ) and pore distributions of the mortar samples can be calculated with mathematical inversion technique.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eMix proportions of cement pastes (wt.%)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eID\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eWater\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"3\"\u003e\n \u003cp\u003eBinder\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePC\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDM\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDB\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCDM10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCDM20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCDM30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCDB10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCDB20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCDB30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"3. Results and Discussion","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003e3.1 Hydration heat\u003c/h2\u003e\n \u003cp\u003eGenerally speaking, the hydration process of cement can be generally classified into four stages: (1) initial reaction period, (2) induction period, (3) acceleration period, and (4) deceleration period [\u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e]. Figure 6 manifests the hydration heat rate variations of different samples from 0 to 72 hours. The hydration evolution tendencies of the specimens with CDM anc CDB were similar to the typical heat flow curve of reference sample (C0). Compared to the C0 sample, the additions of 10\u0026thinsp;~\u0026thinsp;30% CDM and CDB did not change the duration of its induction period shown in Fig. \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e(a), and caused no distinct delay of the time required to reach the hydration heat peak during the acceleration period shown in Fig. \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e(b). It indicated that CDM and CDB did not affect obviously the nature of cement hydration. Nevertheless, CDM and CDB reduced the hydration heat peak of cement, and the heat peak decreased with the increase of CDM and CDB contents [\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eFigure\u0026nbsp;8 manifests the cumulative heat release curves of the C0 sample and the samples with CDM and CDB. For all the samples, a large amount of heat was released rapidly during the first 24 h [\u003cspan class=\"CitationRef\"\u003e25\u003c/span\u003e], and the hydration heat release gradually slowed down after 24 h. Further analysis found that the cumulative hydration heat curves of all the samples was similar in the first 6 h, indicating that the soluble substances dissolved from the C0 paste and the pastes with CDM and CDB were rapid and synchronous at early stages. However, as the hydration reaction continued (from 6 to 72 hours), the cumulative hydration heat decreased obviously with increasing CDM and CDB contents. Compared to the C0 paste, the 72-hour ultimate hydration heat values of the CDM10, CDM20, CDM30, CDB10, CDB20 and CDB30 pastes were decreased 9.5%, 18.4%, 26.1%, 8.0%, 19.8% and 26.3%, respectively.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003e3.2 Strength\u003c/h2\u003e\n \u003cp\u003eFigure 9 presents the flexural and compressive strength evolution of the C0 mortar and the mortars with CDM and CDB. In comparison to the C0 mortar, an obvious decline of the flexural and compressive strength was observed when replacing CDM and CDB at the ages of 7 days and 28 days, and that the strength decreased with increasing the CDM and CDB contents. It indicated that the incorporation of CDM and CDB had adverse impacts on the early strength of cement materials. However, the additions of CDM and CDB could promote the later strength growth. The strengths of the CDM10 and CDB10 mortars were higher than those of the C0 mortar at the ages of 90 days. Compared to the control, the 90 days flexural strengths of the CDM10 and CDB10 mortars were enhanced by 2.4% and 7.3%, the 90 days compressive strengths were enhanced by 3.7% and 8.6%, respectively. Additionally, the 90 days strengths of the mortars with 20% CDM and CDB were also very close to those of the C0 mortar. When the substitution ratio of cement was 30%, the incorporation of CDM and CDB might enhance the dilution effect and cause a certain reduction in strength. Nevertheless, a certain reduction in strength is approved owing the lower price of CDM and CDB attributed to the fact that the raw materials are construction wastes and calcination temperature is relative lower than that of cement clinker production.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n \u003ch2\u003e3.3 Deformation\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e shows the free deformation curves of the C0 mortar and the mortars with CDM and CDB. The C0 mortar emerged a certain shrinkage in 20\u0026deg;C water, and the ultimate shrinkage value reached \u0026minus;\u0026thinsp;0.0142% at the age of 90 days. Compared to the C0 mortar, the mortars with CDM and CDB exhibited a rapid expansion in early ages, and then the expansion curves flattened out in later ages. Additionally, with the increase of CDM and CDB contents, the expansion value increased gradually. The ultimate expansion values of the CDM10, CDM20, CDM30, CDB10, CDB20 and CDB30 mortars were 0.0092%, 0.0162%, 0.022%, 0.0155%, 0.0183% and 0.0282%, respectively. This indicated that expansive characteristics of CDM and CDB was close to those of ordinary MgO expansive agents as reported in the previous literature [\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e]. The hydration of MgO in CDM and CDB could produce a certain expansion, and compensated the shrinkage of pure cement-based materials.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\n \u003ch2\u003e3.4 Hydration products\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e11\u003c/span\u003e manifests the XRD patterns of the C0 paste and the pastes with CDM and CDB cured for 90 days. As shown in Fig. \u003cspan class=\"InternalRef\"\u003e11\u003c/span\u003e, the diffraction peaks of quartz and merwinite were prominent attributed to their low reactivity in the cement hydration process. The weak diffraction peaks of \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS existed in these pastes, indicating that the remaining amounts of \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS were relative low at later ages [\u003cspan class=\"CitationRef\"\u003e34\u003c/span\u003e]. Ettringite and portlandite as two main hydration products of cement clinkers were found obviously, meanwhile other hydration assemblages also existed. The existence of calcite might be due to a certain amount of limestone powder incorporated into PC and the slight carbonation of these pastes. The existence of monocarboaluminate might be due to the reaction of calcite and Al phases in these pastes [\u003cspan class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e36\u003c/span\u003e]. Additionally, obvious diffraction peaks of brucite were also observed in the pastes with CDM and CDB due to the hydration of periclase in CDM and CDB.\u003c/p\u003e\n \u003cp\u003eThe brucite contents of these pastes cured for 90 days are given in Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e quantitatively obtained by XRD Rietveld analysis. For the C0 paste, a slight amount of brucite was generated attributed to the fact that PC contained a minuscule amount of MgO. However, the generation of small amounts of brucite could not compensate the shrinkage of the C0 paste effectively. For the pastes with CDM and CDB, the contents of brucite increased with the increase of the CDM and CDB contents. This is explained by the fact that the hydration of MgO contained in CDM and CDB facilitates the generation of brucite, then promoting the expansion of the mortars.\u003c/p\u003e\n \u003cp\u003e\u003c/p\u003e\u0026nbsp;\u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eThe contents of brucite in cement pastes cured for 90 days (wt.%)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSample\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eC0\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDM10\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDM20\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDM30\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDB10\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDB20\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDB30\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\n \u003ch2\u003e3.5 Pore structure\u003c/h2\u003e\n \u003cp\u003eTo analyze the impacts of CDM and CDB on the microstructure of cement materials, the pore structure of all the 90-days samples were measured by LF-NMR. Figure \u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e manifests the pore size distributions of all the specimens, the pores of all the specimens ranged from 0.003 to 100 \u0026micro;m. According to the effect of the pores with different diameters on the properties of cementitious materials, the pore\u0026thinsp;\u0026gt;\u0026thinsp;0.1 \u0026micro;m is definitely harmful [\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e]. Compared with the C0 mortar, the CDM20, CDM30, CDB20 and CDB30 mortars had more pores with the diameter of 0.003-0.1 \u0026micro;m, as shown in Fig. \u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e. However, the addition of 10% CDM and CDB reduced the pore volume of the pore with the diameter less than 0.1 \u0026micro;m. Additionally, the contents of \u0026gt;\u0026thinsp;0.1 \u0026micro;m pores were also decreased with the additions of 10\u0026ndash;30% CDM and CDB. Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e shows the porosities of all the mortar samples. The total porosities of the CDM10 and CDB10 mortars were obvious lower than that of the C0 mortar. The total porosities of the CDM20 and CDB20 mortars were only slight higher than that of the C0 mortar. Therefore, the mortars with 10\u0026ndash;20% CDM and CDB still exhibited excellent mechanical properties.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003ePorosities of cement mortars cured for 90 days (vol.%)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSample\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eC0\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDM10\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDM20\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDM30\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDB10\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDB20\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCDB30\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePorosity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\n \u003ch2\u003e3.6 Discussion\u003c/h2\u003e\n \u003cp\u003eIt was demonstrated that the additions of CDM and CDB notably reduced the hydration heat release of cement paste, indicating that CDM and CDB was positive to avoid the cracks caused by temperature shrinkage in cement-based materials. The decrease in the hydration heat release may be attributed to the lower content of cement clinker in the pastes containing CDM and CDB compared to the C0 paste. Additionally, the early-age hydration reactivity of quartz, merwinite, and \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS in CDM and CDB exhibited relatively lower than the cement clinker.\u003c/p\u003e\n \u003cp\u003eThe additions of CDM and CDB also reduced the early-age strengths of PC mortars, mainly due to the formation of lower proportions of hydration products in the paste. However, CDM and CDB increased the strengths at later stages. This observation showed that the incorporations of CDM and CDB had obvious positive effects on the long-term properties. This may be explained by that the hydration of \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS in CDM and CDB produced more hydration products at later stages, resulting in the pore structure densification, thereby contributing to the later strength development [\u003cspan class=\"CitationRef\"\u003e37\u003c/span\u003e]. It should be noticed whether or not the hydration of MgO in CDM and CDB also influenced the strength. The contents of MgO in CDM and CDB were 18.1% and 22.3%, respectively, and their proportions in the mixed cements ranged from 10\u0026ndash;30%, resulting in MgO percentages in the mixed cements of 1.8\u0026ndash;6.6%. Previous studies proved that ordinary MgO expansive agents do not, or only slightly decrease the strengths of cement and concrete, when the amount of MgO is less than 6% [\u003cspan class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e39\u003c/span\u003e]. Thus, the hydration of MgO in CDM and CDB should not be recognized as the main factor controlling the strengths of mortars.\u003c/p\u003e\n \u003cp\u003eOn the other hand, with sufficient supply of water, the CDM and CDB addition promoted the formation of brucite, which was generated to induce expansion for compensating the shrinkage of cement materials. Moreover, the brucite contents increased with the increase of CDM and CDB contents, as shown in Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e, thus causing an obvious increase in expansion. In addition, the ultimate expansion of all the cement mortars with 10\u0026ndash;30% CDM and CDB did not exceed 0.06%, which is the maximum expansion of MgO concrete without compromising its soundness according to DL/T 5296\u0026thinsp;\u0026minus;\u0026thinsp;2013. Accordingly, the incorporation of appropriate addition of CDM and CDB could produce the mixed cements with low hydration heat, non-shrinkage and high strength in comparison to PC, meanwhile also promoting the application of WDP, EM and WB in cement materials.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003col\u003e\n \u003cli\u003eProducing new SCMs (CDM and CDB) by calcining the mixtures of WDP and EM, WDP and WB in 1100\u0026nbsp;\u0026deg;C is feasible. The major mineral compositions of CDM and CDB are \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS, periclase, quartz and merwinite. The incorporations of CDM and CDB did not affect obviously the hydration process of Portland cement, but decreased the hydration heat. This is positive to avoid the cracks caused by temperature shrinkage in cement-based materials.\u003c/li\u003e\n \u003cli\u003eReplacement of PC with 10-30% CDM and CDB resulted in strength decrease at early stages. However, the blended cement mortars with 10-20% CDM and CDB gained equivalent or higher strengths at later stages in comparison to the reference C0 mortar. This is mainly related to the pore structure densification and the reduced porosity attributed to the hydration of \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS in CDM and CDB. Additionally, the incorporations of CDM and CDB produced gentle expansions compared to the reference C0 mortar due to the generation of brucite attributed to the hydration of periclase in CDM and CDB. Moreover, the brucite contents increased with the increase of CDM and CDB contents, then causing an obvious increase in expansion.\u0026nbsp;\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work is supported by the National Natural Science Foundation of China (52208279), Natural Science Foundation of Jiangsu Province of China (BK20220639), Natural Science Foundation of the Jiangsu Higher Education Institution of China (20KJB560007) and\u0026nbsp;Postgraduate Research \u0026amp; Practice Innovation Program of Jiangsu Province (SJCX24_1931).\u003c/p\u003e\n\u003ch3\u003eCompliance with ehical standards\u003c/h3\u003e\n\u003ch3\u003eConflict of interest\u003c/h3\u003e\n\u003cp\u003eThe authors declared that they have no conflict of interest in the submission of this manuscript, and manuscript is approved by all authors for publication. I would like to declare on behalf of my co-authors that the work described was original research that has not been published previously, and not under consideration for publication elsewhere, in whole or in part. All the authors listed have approved the manuscript that is enclosed.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eJang JG, Kim GM, Kim HJ, Lee HK (2016) Review on recent advances in CO\u003csub\u003e2\u003c/sub\u003e utilization and sequestration technologies in cement-based materials. Construction and Building Materials 127:762-773.\u003c/li\u003e\n\u003cli\u003eBrito JD, Kurda R (2021) The past and future of sustainable concrete: a critical review and new strategies on cement-based materials. Journal of Cleaner Production 281:123558.\u003c/li\u003e\n\u003cli\u003eAprianti E (2017) A huge number of artificial waste material can be supplementary cementitious material (SCM) for concrete production-a review part II. Journal of Cleaner Production 142: 4178-4194.\u003c/li\u003e\n\u003cli\u003eScrivener KL, Martirena F, Bishnoi S, Maity S (2018) Calcined clay limestone cements (LC3). Cement and Concrete Research 114:49-56.\u003c/li\u003e\n\u003cli\u003eHe ZH, Du SG, Chen D (2018) Microstructure of ultra high performance concrete containing lithium slag. Journal of Hazardous Materials 353:35-43.\u003c/li\u003e\n\u003cli\u003eSamad S, Shah A (2017) Role of binary cement including supplementary cementitious material (SCM), in production of environmentally sustainable concrete: A critical review. International Journal of Sustainable Built Environment 6(2):663-674.\u003c/li\u003e\n\u003cli\u003eMohammadi A, Ramezanianpour AM (2023) Investigating the environmental and economic impacts of using supplementary cementitious materials (SCMs) using the life cycle approach. Journal of Building Engineering 79:107934.\u003c/li\u003e\n\u003cli\u003eJuenger MCG, Snellings R, Bernal SA (2019) Supplementary cementitious materials: New sources, characterization, and performance insights. Cement and Concrete Research 122: 257-273. \u003c/li\u003e\n\u003cli\u003eDuan HB, Miller TR, Liu G, Tam VWY (2019) Construction debris becomes growing concern of growing cities. Waste Management 83:1-5.\u003c/li\u003e\n\u003cli\u003eGao WB, Zhang HG, Ren Q, Zhong YJ, Jiang ZW (2023) A low-carbon approach to recycling engineering muck to produce non-sintering lightweight aggregates: Physical properties, microstructure, reaction mechansim, and life cycle assessment. Journal of Cleaner Production 385:135650.\u003c/li\u003e\n\u003cli\u003eAlcharchafche MAS, Al-mashhadani MM, Ayg\u0026ouml;rmez Y (2022) Investigation of mechanical and durability properties of brick powder-added white cement composites with three different fibers. Construction and Building Materials 347:128548.\u003c/li\u003e\n\u003cli\u003eJiao N, Wan X, Ding JW, Zhang XR, Xue CR (2024) Mechanical properties and microstructure of lime-treated shield tunnel muck improved with carbide slag and soda residue. Construction and Building Materials 428:136419.\u003c/li\u003e\n\u003cli\u003eZhang HY, Ma JY, Chen Z, Wu B (2024) Effect and mechanism of recycled clay brick powder on compressive strength of different types of concretes. Journal of Building Engineering 94:109983.\u003c/li\u003e\n\u003cli\u003eZeng H, Li Y (2024) Effect of waste stone powder on compressive strength and pore structure of concrete in extreme low temperature and complex environment. Journal of Building Engineering 95:110108.\u003c/li\u003e\n\u003cli\u003eChen D, Yang T, Liu KW, Wang AG (2021) Influence of dolomite powder fineness on hydration of blended cements at different curing temperatures. Revista Rom\u0026acirc;nă de Materiale / Romanian Journal of Materials 51(3):395-404.\u003c/li\u003e\n\u003cli\u003eZhang X, Luo Y, Yao W (2022) Effects of dolomite powder on the properties of C30 and C50 concretes. Fullerenes, Nanotubes and Carbon Nanostructures 30(9):896-905.\u003c/li\u003e\n\u003cli\u003eXu JT, Lu DY, Zhang SH, Xu ZZ, Hooton RD (2021) Reaction mechanism of dolomite powder in Portland-dolomite cement. Construction and Building Materials 270:121375.\u003c/li\u003e\n\u003cli\u003eHu HB, Yao W, Wei YQ (2023) Recycling waste dolomite powder in cement paste: early hydration process, microscale characteristics, and life-cycle assessment. Science of the Total Environment 902:166008.\u003c/li\u003e\n\u003cli\u003eWu HX, Gao JM, Liu C, Guo ZH, Luo X (2024) Reusing waste clay brick powder for low-carbon cement concrete and alkali-activated concrete: A critical review. Journal of Cleaner Production 449:141755.\u003c/li\u003e\n\u003cli\u003eLei JS, Yang Y, Chen XH (2024) Mechanics and permeability properties of ecological concrete mixed with recycled engineering muck particles. Journal of Building Engineering 91: 109560.\u003c/li\u003e\n\u003cli\u003eXu LL, Deng M (2005) Dolomite used as raw materials to produce MgO-based expansive agent. Cement and Concrete Research 35(8):1480-1485.\u003c/li\u003e\n\u003cli\u003eCao FZ, Liu Y, Yan PY (2021) Properties and mechanism of the compound MgO expansive agent (CMEA) produced by calcining the mixture of dolomite and serpentine tailings. Construction and Building Materials 277:122331.\u003c/li\u003e\n\u003cli\u003eScrivener KL, F\u0026uuml;llmann T, Gallucci E, Walenta G, Bermejo E (2004) Quantitative study of Portland cement hydration by X-ray diffraction/Rietveld analysis and independent methods. Cement and Concrete Research 34(9):1541-1547.\u003c/li\u003e\n\u003cli\u003e\u0026Aacute;lvarez-Pinazo G, Cuesta A, Garc\u0026iacute;a-Mat\u0026eacute; M, Santacruz I, Losilla ER, De la Torre AG, Le\u0026oacute;n-Reina L, Aranda MAG (2012) Rietveld quantitative phase analysis of Yeelimite-containing cements. Cement and Concrete Research 42:960-971.\u003c/li\u003e\n\u003cli\u003eChen D, Mo LW, Wang AG, Liu KW, Zhang SP, Yang T (2023) The hydration, strength and deformation of Portland composite cements containing light-burnt dolomite and metakaolin. Advances in Cement Research 35(3):135-143.\u003c/li\u003e\n\u003cli\u003eGuo H, Wang Z, Zhao X, Liu J, Ji X, Shi W (2022) Effects of dolomite powder on properties of environment-friendly cement asphalt emulsion composites. Journal of Cleaner Production 369:133321.\u003c/li\u003e\n\u003cli\u003eLiu H, Sun ZP, Yang JB, Ji YL (2021) A novel method for semi-quantitative analysis of hydration degree of cement by \u003csup\u003e1\u003c/sup\u003eH low-field NMR. Cement and Concrete Research 141, 106329.\u003c/li\u003e\n\u003cli\u003eChen D, Mo LW, Liu KW, Wang AG, Zhang SP, Di QF, Yan J (2022) Hydration and pore structure evolution of white cement paste at early age based on \u003csup\u003e1\u003c/sup\u003eH low-field nuclear magnetic resonance. Revista Rom\u0026acirc;nă de Materiale / Romanian Journal of Materials 52(2):203-208.\u003c/li\u003e\n\u003cli\u003eJiang ZL, Pan YJ, Lu JF, Wang YC (2022) Pore structure characterization of cement paste by different experimental methods and its influence on permeability evaluation. Cement and Concrete Research 159:106892.\u003c/li\u003e\n\u003cli\u003eScrivener K, Ouzia A, Juilland P, Mohamed AK (2019) Advances in understanding cement hydration mechanisms. Cement and Concrete Research 124:105823.\u003c/li\u003e\n\u003cli\u003eBriki Y, Zajac M, Haha MB, Scrivener K (2021) Impact of limestone fineness on cement hydration at early age. Cement and Concrete Research 147:106515.\u003c/li\u003e\n\u003cli\u003eZhang J (2022) Recent advance of MgO expansive agent in cement and concrete. Journal of Building Engineering 45:103633.\u003c/li\u003e\n\u003cli\u003eCao FZ, Yan PY (2019) The influence of the hydration procedure of MgO expansive agent on the expansive behavior of shrinkage-compensating mortar. Construction and Building Materials 202:162-168.\u003c/li\u003e\n\u003cli\u003eKrishnan S, Zunino F, Bishnoi S, Scrivener K (2023) Characterisation and hydration kinetics of \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS synthesised with K\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4 \u003c/sub\u003eas dopant. Cement and Concrete Research 167:107119.\u003c/li\u003e\n\u003cli\u003eJi GX, Chi HH, Sun KK, Peng XQ, Cai YM (2024) Effect of limestone waste on the hydration and microstructural properties of cement-based materials. Construction and Building Materials 443:137784.\u003c/li\u003e\n\u003cli\u003eTang J, Wei SF, Li WF, Ma SH, Ji PH, Shen XD (2019) Synergistic effect of metakaolin and limestone on the hydration properties of Portland cement. Construction and Building Materials 223:177-184.\u003c/li\u003e\n\u003cli\u003eZhang JT, Zhang WS, Ye JY, Ren XH, Liu L, Shen WG (2021) Influence of alkaline carbonates on the hydration characteristics of \u0026beta;-C\u003csub\u003e2\u003c/sub\u003eS. Construction and Building Materials, 296:123661.\u003c/li\u003e\n\u003cli\u003eMo LW, Liu M, Tabbaa AA, Deng M, Lau WY (2015) Deformation and mechanical properties of quaternary blended cements containing ground granulated blast furnace slag, fly ash and magnesia. Cement and Concrete Research 71:7-13.\u003c/li\u003e\n\u003cli\u003eSherir MAA, Hossain KMA, Lachemi M (2016) Self-healing and expansion characteristics of cementitious composites with high volume fly ash and MgO-type expansive agent. Construction and Building Materials 127:80-92.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"materials-and-structures","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"maas","sideBox":"Learn more about [Materials and Structures](http://link.springer.com/journal/11527)","snPcode":"11527","submissionUrl":"https://www.editorialmanager.com/maas/default2.aspx","title":"Materials and Structures","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"admixtures, hydration, strength, deformation, microstructure","lastPublishedDoi":"10.21203/rs.3.rs-5019108/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5019108/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn this study, new types of supplementary cementitious materials (SCMs) were manufactured by the calcination of construction wastes such as engineering muck (EM) and waste brick (WB) in the presence of waste dolomite powder (WDP). The impacts of calcined dolomite-muck (CDM) and calcined dolomite-brick (CDB) on the performances of Portland cement were investigated, the reaction mechanism of CDM and CDB in pastes was also analyzed. Results showed that the mineral compositions of CDM and CDB are β-C\u003csub\u003e2\u003c/sub\u003eS, periclase, quartz and merwinite. The incorporations of CDM and CDB decreased obviously the hydration heat and strengths of cement-based materials at early stages. However, the blended cement mortars with 10-20% CDM and CDB obtained similar or higher strengths at later stages compared to the control mortar. This is attributed to the hydration of β-C\u003csub\u003e2\u003c/sub\u003eS in CDM and CDB, resulting in the pore structure densification and the lower porosity at later ages. In addition, the mortars with CDM and CDB also produced gentle expansions attributed to the hydration of periclase in CDM and CDB, which is beneficial for mitigating the shrinkage.\u003c/p\u003e","manuscriptTitle":"Performances of cement-based materials incorporating new SCMs produced by the co-calcination of construction wastes with waste dolomite powder","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-16 15:32:27","doi":"10.21203/rs.3.rs-5019108/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2024-12-20T07:55:44+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-12-13T13:35:31+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Materials and Structures","date":"2024-11-27T21:57:22+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-11-26T17:27:35+00:00","index":"","fulltext":""},{"type":"submitted","content":"Materials and Structures","date":"2024-11-26T00:52:58+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"materials-and-structures","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"maas","sideBox":"Learn more about [Materials and Structures](http://link.springer.com/journal/11527)","snPcode":"11527","submissionUrl":"https://www.editorialmanager.com/maas/default2.aspx","title":"Materials and Structures","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"f8929f94-8872-4d57-9070-f279dbbf7eab","owner":[],"postedDate":"December 16th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-10-27T16:33:31+00:00","versionOfRecord":{"articleIdentity":"rs-5019108","link":"https://doi.org/10.1617/s11527-025-02843-2","journal":{"identity":"materials-and-structures","isVorOnly":false,"title":"Materials and Structures"},"publishedOn":"2025-10-23 16:17:01","publishedOnDateReadable":"October 23rd, 2025"},"versionCreatedAt":"2024-12-16 15:32:27","video":"","vorDoi":"10.1617/s11527-025-02843-2","vorDoiUrl":"https://doi.org/10.1617/s11527-025-02843-2","workflowStages":[]},"version":"v1","identity":"rs-5019108","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5019108","identity":"rs-5019108","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}