混杂纤维混凝土高温后力学性能研究

MECHANICAL PROPERTIES OF HYBRID FIBER REINFORCED CONCRETE AT HIGH TEMPERATURE

为研究玄武岩-纤维素混杂纤维混凝土高温后的力学性能,对不同玄武岩纤维长度(6 mm、12 mm、30 mm)及不同温度(20℃、200℃、400℃、600℃)下的混杂纤维混凝土进行了立方体抗压及劈裂抗拉试验。结果表明:普通混凝土在200℃下抗压强度达到峰值,而混杂纤维混凝土的抗压强度则在400℃时达到最高,随后抗压强度逐渐减小;普通混凝土与纤维混凝土的劈裂抗拉强度均随温度升高而下降,600℃后,混凝土的劈裂抗拉强度残余率仅剩64.9%;当玄武岩纤维长度为12 mm时,混杂纤维混凝土的耐高温能力最强,在600℃时,其抗压强度、劈裂抗拉强度残余率分别为84.8%、68.6%。

In order to study the mechanical properties of basalt-cellulose hybrid fiber concrete after high temperature, cubic compressive and splitting tensile tests were carried out for different basalt fiber lengths (6 mm, 12 mm, 30 mm) and different temperatures (20 ℃, 200 ℃, 400 ℃, 600 ℃). The test results show that the compressive strength of ordinary concrete achieves the maximum strength at 200 ℃, while the hybrid fiber concrete reaches the maximum strength at 400 ℃, and then the compressive strength decreases gradually. The splitting tensile strength of ordinary concrete and fiber concrete decreases with the increase of temperature. After 600 ℃, the residual tensile strength of concrete is only 64.9%. When the basalt fiber length is 12 mm, the high temperature resistance of the hybrid fiber concrete is the strongest. At 600 ℃, the residual compressive strength and the residual splitting tensile strength are 84.8% and 68.6%, respectively.