The Effect of Recycled Sand on the Tensile Properties of Engineered Cementitious Composites

Abstract

This research aims to investigate the feasibility of replacing natural sand (NS) with recycled sand (RS) to enhance the mechanical property of engineered cementitious composites (ECC). For a comparative study, ECCs incorporating natural sands (NS) and recycled sands with different sieve sizes were taken as experimental subjects. The results demonstrated that RS-ECC possessed better tensile properties featuring saturated cracks and superior strain-hardening behavior than that of NS-ECC. The highest tensile strain capacity of RS-ECC was up to 7%. Meanwhile, the compressive and flexural strengths of RS-ECC were over 50 and 20 MPa. The pseudo-strain-hardening (PSH) index of the RS-ECC-20 grid and RS-ECC-12 grid were 141 and 201, which increased by 46% and 70% than that of NS-ECC. Furthermore, the thicker weak ITZ and comparatively aggregate/ITZ ratio were found in the RE-ECC by a microstructure test, which revealed and explained the mechanism for the lower matrix fracture toughness of RS-ECC.

A contribution to the study of mortars prepared with recycled sand

“…Moreover, the excessive exploitation of river sand, which generally causes a multitude of environmental problems, has pushed the majority of governments around the world to issue rules for the purpose of limiting or preventing the illegal extraction of river sand (Dong et al,, 2022).…”

Optimisation of the Mechanical Properties and Mix Proportion of Multiscale-Fibre-Reinforced Engineered Cementitious Composites

“…The micromechanical model of ECCs is focused on microstructural and microscopic phenomena [5,16]. The damage of cement matrix composites starts from the microscopic scale [17][18][19], where many cracks are generated in the microstructure; stress concentration occurs at the cracks. These small and irregular cracks develop and accumulate rapidly, and when the cracks reach saturation, macroscopic main cracks can be observed; eventually, the main cracks crack completely, leading to the destruction of the material.…”