In this study, structural light-weight concretes produced by Pumice (LWC) and concretes with normal-weight aggregate (NWC) were investigated. Compressive strength and weight loss of the concretes were determined after being exposed to high temperatures (20, 100, 400, 800, 1000 degrees C). To achieve these objectives, 12 different types of concrete mixtures were produced. In producing the mixtures, silica fume (SF) was used to replace the Portland cement in the ratios of 0%, 5% and 10% by weight. Half of the mixtures were obtained by adding superplasticizers (SP) to the above mixtures in the ratio of 2% by weight. In conclusion; unit weight of LWC was 23% lower than that of NWC. The LWC containing 2% SP could retain 38% of the initial compressive strength. Rate of deterioration was higher in NWC when compared to LWC. The loss of compressive strengths increased depending on the ratio of using SF at about 800 degrees C and over. (C) 2008 Elsevier Ltd. All rights reserved.