Development of engineered cementitious composite with moderate tensile properties using polyester fibers

Abstract

In recent years, the use of reinforced cementitious composites has increased manifold for structural rehabilitation purposes. The present study concerns the development of a special variant of ECC, which is low-cost but has moderate tensile strength and ductility. Widely available polyester fiber was chosen, which was about ten times cheaper but about four times weaker than the preferred but expensive PVA fibers. Micromechanics-based mathematical model was used for fiber optimization to attain the multiple and strain hardening phenomena of the ECC. Different ECC mixes were prepared to investigate the effect of the matrix toughness on the tensile properties of ECC. ECC, with a strong matrix, failed to attain multiple cracking after 28-days of tensile testing because the fracture toughness exceeded the fiber bridging energy. The matrix was made weaker by increasing the amount of fly ash, and the desired strain hardening phenomena was achieved after 28-days of tensile testing. A low-cost ECC was developed, which used 3% polyester fiber by volume; the tensile strength and strain capacity of ECC was 2.17 MPa and 1.88%, respectively.