Mechanical performance of sprayed engineered cementitious composite using wet-mix shotcreting process for repair applications

Abstract

This paper presents an experimental study on the fundamental performances of a sprayed engineered cementitious composite (ECC) in repair systems. ECC serving as a repair material has been expected to be highly effective in providing durable repaired structures because of the tight crack width control and high delamination resistance. For this study, a polyvinyl alcohol (PVA) fiber-reinforced ECC (PVA-ECC) that exhibits suitable properties for wet-mix shotcreting in the fresh state and strain-hardening behavior in the hardened state was sprayed and tested. The experimental results show that the sprayed ECC exhibits strain-hardening behavior with strain capacities comparable with the cast ECC with the same mixture proportion. It is also revealed that when sprayed ECC is used as a repair material, both load-carrying capacity and ductility represented by deformation capacity at peak load of repaired beams in flexure are obviously increased in comparison with those of commercial prepackaged mortar (PM) repaired beams. The significant enhancement of energy absorption capacity and tight crack width control in ECC repair systems using a wet-mix shotcreting process suggests that sprayed ECC can be effective in extending the service life of rehabilitated infrastructures.