Effect of elevated temperature on the propeties of concrete produced with fly ash and silica fume

Abstract

This paper studies on the properties of concrete produce with coal ash as aggregate and binder from Ordinary Portland cement (OPC), fly ash (FA), silica fume (SF). OPC has been partially replaced by 16 % FA and 5.3 wt.% SF. The samples were mixed and moulded into 70.7 × 70.7 × 70.7 mm cubes. After curing 7 days under standard conditions, the samples were dried at 100 ^oC for 24 hours, and heated at temperature leves of 200, 400, 600 and 800^oC for 2 hours, then cooled to room tempereture. Bulk density and compresive strength were determined at each firing temperature. The temperarute up to 800 ^oC, their bulk density loss of 2 % and relative residual compressive strength of 58 %. The change in the interfacial tranzition zone of cement harder and aggregate (ITZ) with increasing temperature determined by scanning electron microscop (SEM).