Tensile performance and impact resistance of Strain Hardening Cementitious Composites (SHCC) with recycled fibers

Strain Hardening Cementitious Composites (SHCC) are fiber reinforced composites exhibiting strain hardening and multiple cracking behaviors. The Polyvinyl Alcohol (PVA) fibers used in SHCC are expensive for normal civil engineering applications, so one kind of Polyethylene terephthalate (PET) fibers recycled from waste plastics are used in this study as a substitute of PVA fibers. Uniaxial tensile test was carried out on SHCC samples made with PVA or PET fibers where the PET-SHCC was found to behave poorer than the PVA-SHCC due to the weaker bond between PET fibers and matrix. Nevertheless, in the modified Charpy impact test which was designed to evaluate the impact energy absorption ability of SHCC, the PET-SHCC dissipated a great amount of energy comparable to that by PVA-SHCC, indicating that PET fibers can provide excellent impact resistance to cementitious composites. To reveal the mechanism of impact energy absorption, a physical model was developed to simulate the impact test, which can well support the experimental observations. Based on above findings, a hybrid mix of 1 vol% PVA fibers and 1 vol% PET fibers is recommended for practical applications to provide adequate tensile performance and excellent impact resistance with eco-friendly ingredients at low cost.