FACTORS INFLUENCING THE SULFATE RESISTANCE OF CONRETE

Cement is the most popular building material for the civil engineering structure. The performance of these structures in the terms of stability and strength has resisted by time, but the life span of these structures has been always a concern. From the environmental aspect this is becoming chemically more aggressive. Atmosphere is found to have increment of sulfur dioxide concentrations, carbon dioxide and chloride concentrations. Sulfur oxides are harmful for the concrete, whereas chloride is harmful for the reinforcing steel. As e consequence, the life span of the reinforced concrete structures is evidently threatened compared to the estimated life span for almost 90 years. The impact of sulfate ions in deterioration of concrete is studied intensively. Concrete is the most widely used material, because of its performance in the concrete strengths. But a serious problem might come by a result of the chemical attack, concrete cracks and consequently the deterioration of concrete. The reaction of sulfate ions (SO42-) with the cement hydrated products is a volume increasing reaction, which leads to changing in volume and it is shown as sulfate attack of concrete. Based on the available literature, this study presents the use of composite cements, which by time will be affected by the parameters related to the sulfate resistance of cement and concrete.