Impact of particle shape of crushed natural and recycled fine aggregate on fresh and hardened mortar properties

Abstract Increasing the amount of crushed natural and recycled fine aggregate in mortar and concrete can help reduce the depletion of resources and increase the recycling rate of construction and demolition waste. Differences in particle shape and angularity influence fresh and hardened mortar and concrete properties. Here a multiple linear regression analysis is performed to investigate the impact of particle shape and angularity on rheological and strength properties of mortar. Shape and angularity are quantified by micro computed tomography. Mortar mixtures with five different materials and varying other mix design parameters like water to cement ratio, binder to aggregate ratio and shape of grading curve are produced. Results indicate that particle shape and angularity have a complex impact on fresh and hardened mortar properties that often interact with other mix design parameters. Careful composition of the aggregate fraction with respect to shape and angularity is necessary to maintain sufficient mortar properties.