高温中纤维矿渣混凝土强度劣化及其计算方法

Strength Deterioration and Its Calculation Method of Fiber Slag Concrete in High Temperature

通过高温中纤维矿渣微粉混凝土强度试验,探讨了温度、矿渣掺量、钢纤维掺量和聚丙烯纤维掺量对高温中混凝土强度的影响。结果表明,高温中纤维矿渣微粉混凝土强度随温度的升高不断劣化,400℃可作为抗压强度劣化的分界点,劈拉强度和抗折强度随温度升高呈斜直线下降,降幅大于抗压强度;钢纤维能显著提高高温中混凝土强度,聚丙烯纤维和矿渣微粉对高温中混凝土的爆裂和强度劣化均有一定程度的影响。在统计分析的基础上,提出了考虑温度和钢纤维掺量影响的高温中纤维矿渣微粉混凝土强度计算公式。

Through the strength tests of fiber reinforced granulated blast furnace slag concrete in high temperature, the influences of temperature, replacement ratio of slag powder, steel fiber content and polypropylene fiber content on the strength of concrete in high temperature are analyzed. The results indicate that the strength of concrete deteriorates as the temperature grows, the demarcation point of the deterioration of compressive strength is 400℃. The splitting tensile strength and flexural strength decrease along the inclined straight line as the temperature grows, and the decreasing range is more than that of the compressive strength. The addition of steel fiber can evidently increase the strength of fiber reinforced granulated blast furnace slag concrete in high temperature. Both polypropylene fiber and slag powder have the effect on the bursting and strength deterioration of concrete in the high temperature. Based on the statistical analysis, the calculation formulas of strength of fiber reinforced granulated blast furnace slag concrete are put forward which concerns the effect of temperature and mixing amount of steel fiber.