土木外文翻译--高温下钢筋混凝土中钢筋的性能(编辑修改稿)

土木外文翻译--高温下钢筋混凝土中钢筋的性能(编辑修改稿)内容摘要：

and splitting tensile strength of the S220 steel rebars are reducing with the increase of temperatures over 800176。 C. A similar behavior can be seen from the test results of S420ribbed steel rebars (Figure 2). All high temperature subjected steel specimens became more ductile temperatures above 800176。 C. Figure 1: Stressstrain curve of S220 steel rebar. Figure 2: Stressstrain curve of S420ribbed steel rebar. . Yield Strength Yield strength of both reinforcing steel rebars was affected with the elevated exposure temperatures. It can be concluded from Figure 3 that there is no variation in yield strength of reinforcing steels with cover up to 300176。 C. Plain reinforcing steel rebars have experienced the strain hardening already for this temperature. According to Eurocode and TS EN 1993, before 400176。 C there is no 20 decrease in yield strength, but after this temperature a significant yield strength loss occurs [9]. The yield strength losses of both S220 and S420 steel rebars were 46% and 84% for 800176。 C exposure temperature, respectively. For further increase of temperature at 950176。 C, yield strength decreases were 64% and 89%, respectively. According to these results, the remaining yield strength of S220 steel reinforcing rebar is higher than S420ribbed steel rebar after hightemperature exposure. Figure 3: Yield strength of steel rebars against temperature. . Tensile Strength The tensile strength variation of steel reinforcement rebars exposed to elevated temperatures is given in Figure 4. On the light of these results, there was no significance reducing of tensile strength for both types of steel rebars up to 500176。 C tensile strength losses of both S220 and S420 steel rebars were 51% and 85% for 800176。 C exposure temperature, respectively. For the highest exposure temperature at 950176。 C, tensile strength decreases were 60% and 90%, respectively. According to these results, the remaining tensile strength of S220 steel reinforcing rebar is higher than S420ribbed steel rebar after hightemperature exposure. However, it should be considered that the possibility of plete strength loss of steel rebars at high temperatures when a structure is subjected to a huge fire. The remaining strengths of both reinforcing steel rebars after 500176。 C are lower than the design strengths of these steels. Consequently, the remaining strength of the steel rebars in structures is influenced with the exposure time and type of fire depending on the heat transfer through concrete cover to steel parts [10]. Figure 4: Tensile strength of steel rebars against temperature. . Elongation The relation between high temperature and splitting elongation ratio can be seen from Figure 5. The figure is demonstrated that both steel rebars show a same elongation behavior under elevated temperatures. The elongation ratios of S220 steel rebars are higher than S420 rebars depending on the ductile fracture behavior of this steel. After a fire inside the reinfor。