In this study, the mechanical properties of structural rebars have been investigated after exposure of elevated temperatures. The mortar was prepared with CEM I 42.5N cement and fired clay. The S 420a, circle divide 16 mm ribbed steel bars were used to prepare 56 x 56 x 290, 76 x 76 x 310, 96 x 96 x 330 and 116 x 116 x 350 mm specimens with the covers of 20, 30, 40 and 50 mm against elevated temperatures up to 800 degrees C. The rebars were embedded in mortars to prepare specimens, and then specimens were exposed to 20, 100, 200, 300, 500 and 800 degrees C temperatures for 3 h, individually. After cooling process, specimens were cured for 28 days. The mechanical tests were conducted on cooled specimens, and the ultimate tensile strength, yield strength and elongation of mortar specimens at various temperatures were also determined at the end of the experiments. @ 2007 Elsevier Ltd. All rights reserved.