EXPERIMENTAL INVESTIGATION OF SELF PROTECTED UNDER WATER ANTIWASH OUT RESISTANCE CONCRETE IN MARINE AND FRESH WATER

Underwater construction projects such as man-made islands, piers, and bridge foundations often face the challenge of washout, especially in marine environments where tidal forces and direct exposure to seawater can deteriorate freshly placed concrete. Washout not only reduces material efficiency but also affects the durability and strength of the structure. To mitigate these issues, this study introduces a self-protected underwater concrete incorporating an anti-washout admixture (AWA), specifically VITCON 2014 AWA, to improve washout resistance in both marine and freshwater environments. The experimental program evaluated the effect of AWA on the concrete’s rheological and durability properties. Key tests included non-dispersion testing (Plunge Test, CRD C61), workability measurements (slump test, flow table, L-box, and U-box), and pH assessments in both marine and freshwater. Parameters such as varying water-to-cement ratios and AWA dosages were examined. Results indicate a significant reduction in mass loss and improved cohesion in the mixes containing AWA, with enhanced viscosity contributing to superior washout resistance. The modified concrete showed stable behavior in underwater placement conditions, demonstrating improved performance against segregation and loss of cement paste. The study concludes that anti-washout admixtures are effective in producing durable underwater concrete suitable for marine applications, with enhanced workability and stability under turbulent conditions.