Development of novel set-up for measuring performance of underwater concrete for repair applications

Abstract

Underwater Concrete Latexes including Styrene-Butadiene Rubber (SBR) and Antiwashout Agents (AWA) are widely used to improve adhesion and bonding properties of cementitious-based materials used for repair applications. The behavior of underwater concrete needs to be enhanced for it to withstand the extreme weather conditions exerted on it. To achieve this objective, a novel set-up, which roughly simulates real-life harsh casting environment, was implemented to observe the behavior of the poured concrete. Afterward, the effect of the added polymers on the stability of the intended flowable self-consolidating concrete (SCC) through placement and after the hardening phase were evaluated. Moreover, the bond properties to existing concrete substrate and steel bars are investigated in the presence of those latexes. Focus weight was directed towards highlighting the improved stability responses such as viscosity, flowability and washout resistance according to the European Guidelines for SCC. Results showed that introducing additives such as VMA and SBR to the mixture can boost the concrete characteristics to become normally casted underwater like it is casted above water.