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.

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