Performance of Fly Ash Blended Cement Laterized Concrete in Sulphate Environment

Abstract

The deterioration of concrete structures owing to the existence of sulphate in soils, groundwater and marine environments is an eminent observable fact. The use of blended cements incorporating supplementary cementing materials is becoming regular in such aggressive environments. This paper presents the results of an research on the performance of 36 Fly ash (FA)/ordinary Portland cement (OPC) blended cement Laterized concrete (LATCON) mixtures with immersion period of 28 and 90 days in environments characterized by the presence of magnesium sulphate (2%, 4% and 8%). The concrete mixtures comprise a combination of 20% FA substitute to OPC and 10%, 20%, 30% content of laterite replacement to sand as fine aggregate and granite stone as coarse aggregate with water-to-binder ratio of 0.55. Background experiments like strength and fresh properties, pozzolanic activity were conducted. Deterioration of concrete due to sulphate attack was evaluated by assessing concrete weight loss at 28 and 90 days immersion period. The results show that, as the MgSO4 concentration increases, the compression strength decreases.