Micromechanics based design approach for understanding the behaviour of an ECC beam

Abstract

This paper deals with micromechanics based design approach for modeling the flexural behaviour of a steel reinforced Polyvinyl Alcohol Engineered Cementitious Composite (PVA-ECC) beam. First, micromechanical models were developed to evaluate the peak tensile strength and strain of PVA-ECC. Then, generalised stress-strain relationships were derived for both uni-axial tension and compression. Next, Stress block parameters, which are associated with respective stress-strain relationships, were derived. Finally, a model for evaluating the flexural capacity of an ECC beam was developed. The results obtained by testing the model were in agreement with other analytical results available in the literature. However, to confirm the flexural behaviour and develop a unified design approach more experimental investigations are needed. Generally, the yielding behaviour of structural steel provides the ductility to reinforced concrete structures over normal loadings. However, during earthquake excitation and heavy impact conditions structures undergo large deformations. To withstand such loads they need to have more ductility that is inherent. In this context, it is noteworthy that ductility of reinforcements prevents concrete from brittle cracking. However, ductility related concerns can be solved to a large extent by using ductile concrete materials such as Slurry Infiltrated Fibre Concrete (SIFCON), Slurry Infiltrated Mat Concrete (SIMCON) , Polyethylene Engineered Cementitious Composite (PE-ECC) and Polyvinyl Alcohol Engineered Cementitious Composite (PVA-ECC) in structural constructions.