Experimental investigation and numerical simulation on uniaxial tensile behavior of hybrid PVA-ECC

Engineered Cementitious Composites (ECC) with multiple cracking and strain-hardening characteristics can meet the high requirements of infrastructure for safety and durability, however, the high cost of oiled polyvinyl alcohol (PVA) fiber in ECC limits the extensive application of ECC. The price of regular unoiled PVA fiber is relatively lower, therefore, hybrid PVA-ECC with redesigned mix proportion of unoiled and oiled PVA fibers can reduce the cost of PVA-ECC, and it exhibits satisfactory mechanical properties at the same time, offering a wider application prospect than the oiled PVA-ECC. The tensile stress-strain relation of hybrid PVA-ECC is an important property for structural design, however, the lack of theoretical method for predicting tensile stress-strain relation of hybrid PVA-ECC hinders the application of hybrid PVA-ECC in practical engineering. Based on the micromechanical model of multiple cracking, the crack space calculation model, the series spring model and the random probability distribution model, the numerical simulation model for predicting tensile behavior of hybrid PVA-ECC was proposed. The mix proportion of hybrid PVA-ECC was redesigned based on the characteristics of different PVA fibers. The uniaxial tensile test was conducted to investigate the uniaxial tensile behavior of hybrid PVA-ECC and to provide a reference for validating the numerical model.