Effect of morphological parameters of natural sand on mechanical properties of engineered cementitious composites

Engineered Cementitious Composite (ECC) is an advanced construction material exhibiting tensile strain-hardening and multiple-cracking behavior. The tensile performance of ECC is known to be sensitive to the amount and size of sand used. Most studies on ECC have been performed with fine silica sand, while limited studies used coarser sand. However, the influence of morphological parameters of sand on the mechanical performance of ECC has not yet been explored, which is the focus of the present study. The morphological parameters (including particle roundness and sphericity) of sand were objectively determined using image analysis and computer algorithms, while the ECC compressive and tensile properties were experimentally measured. It was concluded that decreasing sand particle roundness and sphericity led to enhancements in compressive strength, ultimate tensile strength and tensile strain capacity of ECC. Gabbro sand, with the lowest roundness and sphericity among the four natural sand types studied, resulted in the best ECC mechanical properties. This natural sand can serve as an effective alternative to the typical manufactured fine silica sand used in ECC with reduced material cost and environmental impact. The findings of this study support the broader utilization of local natural sand in ECC in practical applications.