玄武岩纤维再生混凝土高温水冷损伤试验研究

Experimental Study on High-temperature Water Cooling Damage of Basalt Fiber Reinforced Recycled Concrete

为研究消防喷水灭火对纤维再生混凝土力学特性的影响,以玄武岩纤维(BF)体积掺量和历经最高温度为变化参数,共设计90个玄武岩纤维再生混凝土(BFRC)标准立方体试块,进行高温喷水冷却和抗压强度—声发射(AE)试验,探讨BF体积掺量和历经最高温度对BFRC力学性能的影响。结果表明,当温度升到1 000℃,试块表面脱落,骨料全部露出,试块的完整性遭到严重破坏;试块的剩余抗压强度在温度为200~400℃时下降趋缓,抵抗高温的效果明显;BFRC的高温喷水冷却受压损伤过程可分为初期压密与裂纹萌生阶段、裂纹扩展汇集阶段和峰后破坏阶段,各阶段的声发射振铃累计计数具有明显差异;拟合得到消防喷水灭火后BFRC抗压强度计算公式,可为评估不同BF体积掺量及历经最高温度对BFRC抗压强度的影响提供参考。

Using Basalt Fiber(BF)volume admixture and the highest duration temperature as the parameters of variation,a total of 90 standard cubic specimen blocks of Basalt Fiber Reclaimed Concrete(BFRC)were designed to conduct high temperature sprinkler cooling and compressive strength-acoustic emission(AE)tests in order to investigate the effect of BF volume admixture and the highest temperature elapsed on the mechanical properties of BFRC.The results show that the test piece's integrity is severely broken,its surface breaks off,and all of the aggregate is revealed when the temperature reaches 1000℃;The specimen's residual compressive strength gradually drops when the temperature is in the range of 200℃and 400℃,and the effect of resisting high temperatures is obvious;The first compression-tightening and crack-emergence stage,the crack extension and pooling stage,and the post-peak damage stage are the three phases of the high-temperature water-jet-cooled compressive damage process of the BFRC;There are clear differences in the cumulative counts of acoustic emission ringing at each stage;The formula for determining the compressive strength of BFRC following fire sprinkler installation may be used as a guide for assessing the impact of varying BF volume content and the maximum duration temperature on BFRC's compressive strength.