高温作用下不同掺量玄武岩纤维混凝土力学性能研究

Study on Mechanical Properties of Basalt Fiber Reinforced Concrete Under High Temperature

为了研究高温作用下玄武岩纤维混凝土的力学性能,分析不同温度作用下的混凝土(玄武岩纤维掺量分别为0、0.2%和0.4%)的物理变化,并结合单轴压缩试验,进一步研究高温对混凝土力学性能的影响。结果表明:基准混凝土与玄武岩纤维混凝土随着温度的升高,其烧失量均逐渐增加,玄武岩纤维的掺加对高温作用下混凝土水分消散阻止作用较小;表面所产生裂纹数逐渐增加,基准混凝土所产生的裂纹无论是数量还是长度与宽度均为最大。可见,玄武岩纤维在混凝土高温时所起作用主要为减少混凝土爆裂现象的产生;抗压强度均表现为先升高后降低的趋势,其中相同温度时,玄武岩纤维混凝土强度始终高于基准混凝土,且随着纤维掺量的增加而增加;由于玄武岩纤维具有较好的阻裂效果,因此当试样破坏时,玄武岩纤维混凝土破坏程度小于基准混凝土。玄武岩纤维在高温作用下主要作用为减少爆裂现象对水分蒸发的影响较小。

In order to study the mechanical properties of basalt fiber reinforced concrete under high temperature,the physical changes of concrete(the basalt fiber content of 0,0.2%and 0.4%,respectively)under different temperatures were analyzed,and the uniaxial compression test was combined to further study the high temperature on mechanical properties of concrete.The results shows that the reference concrete and basalt fiber concrete increase with the temperature variation,The loss on ignition increases gradually,the addition of basalt fiber has less effect on the moisture dissipation of concrete under high temperature.The number of cracks generated on the surface gradually increases,and the cracks generated by the reference concrete are the largest in number,length and width.It shows that the role of basalt fiber in the high temperature of concrete is mainly reducing the occurrence of concrete bursting.The compressive strength shows an increasing trend at the first,and then it decreased.at the same temperature,The strength of basalt fiber concrete is always higher than that of the reference concrete,and increases with the variation of fiber content.Since the basalt fiber has a good crack resistance effect,when the sample was destroyed,the basalt fiber concrete was less damaged than that of the reference concrete.