Design of an explicit crack bridging constitutive model for engineered cementitious composites using polyvinyl alcohol (PVA) or polyethylene (PE) fiber

Abstract

This paper aims to establish an explicit crack bridging model that can link engineered cementitious composites (ECC) behavior from single fiber to single crack scale, which is great of designing ECC featuring pseudo tensile strain hardening and multiple cracks expanding by tailoring microstructure and materials selection. In this study, fiber bridging stress was divided into three parts including fiber bridging stress with no rupture, fiber debonding fracture stress, and fiber pullout fracture stress. Subsequently, the fundamental crack bridging model was emerged when fiber bridging stress with no rupture subtracted from the fiber rupture stress in debonding and pullout stage. Moreover, two-way pullout and Cook-Gordon effect were also considered to establish the complete model. It was found that the two-way pullout situation of polyvinyl alcohol (PVA) fiber has a significant influence on the crack opening width due to its slip hardening property, while the Cook-Gordon effect presents a faint crack width increment for PVA-ECC. However, the Cook-Gordon effect makes a significant contribution to the crack opening width of the composite produced by polyethylene (PE). This building intelligible model presents a better prediction for ECC through the comparison of experimental data or real average crack width in previous models, thus confirming the validity of this model.