Manufactured sand particle size and mechanical behaviour of strain-hardening cementitious composites

Resumen

This study investigates the replacement of natural sand with manufactured sand in PVA fibre-reinforced strain-hardening cementitious composites (SHCC), with emphasis on the influence of maximum particle size on mechanical behaviour. Five mixtures were produced using natural sand and manufactured sand with maximum particle sizes ranging from 0.30 to 2.36 mm. The mixtures were experimentally evaluated through compressive, uniaxial tensile, and bending tests, together with fracture characterization of the corresponding plain matrices. The results show that replacing natural sand with fine manufactured sand (0.30 mm) does not significantly affect compressive strength, Young’s modulus, or tensile and flexural performance. Increasing particle size had negligible influence on compressive properties but significantly affected post-cracking behaviour. Although first-cracking stress increased, tensile strain capacity, flexural deflection capacity and crack number decreased for the largest particle size investigated (2.36 mm), indicating reduced strain-hardening stability and earlier crack localization. A strong exponential correlation was identified between tensile strain capacity and flexural deflection capacity. Manufactured sand is therefore a viable alternative, provided that particle size is carefully controlled to maintain a balance between strength and ductility.