The influence of clay composition on the severity of attack due to thaumasite sulfate attack (TSA) on concrete made with CEM I and CEM I blended with 10% Limestone Filler (LF) was investigated. Concrete specimens were exposed to weathered Lower Lias Clay (LLC), for which the water soluble sulfate corresponded to the BRE sulfate class of DS-2, for 12 months at 5 and 20 C. A parallel study was carried out in which specimens of the same concretes were placed in sulfate solutions equivalent to DS-2 and DS-4 at the same temperatures. It was found that concrete exposed to clay with sulfate design class DS-2 deteriorated at a faster rate than corresponding specimens in DS-2 solution and at a similar or greater rate to those exposed to the DS-4 sulfate solution. This suggests that the aggressively of clay and resulting concrete deterioration could exceed what might be observed in concrete exposed to equivalent standard test solutions.
Journal / conference name:
Construction and Building Materials