SULFATE ATTACK ON PLAIN AND BLENDED CEMENTS IN SEA WATER

As part of a comprehensive program to study the effect of the conjoint presence of chlorides and sulfates on the sulfate resistance of hydrated cements, this study was conducted to investigate the sulfate attack of two plain cements (Type I and Type V) and three blended cements made with fly ash, silica fume and blast furnace slag in marine environments. The performance of these cements was evaluated by exposing the specimens to a fresh sea water for a period of two years and measuring the strength development, reduction in compressive strength, and expansion of the mortar specimens, visual inspection, weight change of the concrete specimens; and mineralogical analysis using x-ray diffraction technique of cement paste specimens. The results of these tests indicated that the sulfate attack was somewhat hindered on plain and blended cements despite the high sulfate concentration in the sea water medium which is classified as “aggressive” and the relatively long exposure period