Properties of fly ash geopolymer concrete in seawater environment

Abstract

This paper presents properties of fly ash geopolymer concrete subjected to continuous immersion in 3.5% NaCl solution and accelerated wetting drying at 80OC and 24-hour cycle in NaCl solution. Three geopolymer mixtures and a control mix with target strength of higher than 55 MPa were evaluated. Change in compressive strength, effective porosity, and weight were observed. There was no significant decrease in strength for both geopolymer and OPC after exposed to the continuous immersion and cyclic wetting drying. Continuous immersion for 365 days changed the effective porosity of the geopolymer concrete. The effect of a change in porosity could be seen from a marginal weight change of the geopolymer concrete. The geopolymer concrete was found to perform better under cyclic exposure than the OPC concrete judging from the compressive strength, porosity and weight change were considered.