基于SEM的玄武岩纤维混凝土力学性能及微观结构研究

Study on Mechanical Properties and Microstructure of BFRC Based on SEM

主要研究了玄武岩纤维的掺入对混凝土抗压、抗拉以及抗折性能的影响,并通过SEM电镜扫描以及孔隙率测定对玄武岩纤维混凝土的微观结构进行分析。试验发现玄武岩纤维混凝土的抗压、抗拉以及抗折强度相对于素混凝土最大提升率分别为28.2%,22.7%及15.3%。均匀分布的玄武岩纤维能在混凝土内部形成致密的三维空间网状结构,极大地提升了混凝土界面微观区域的力学稳定性,抑制了混凝土界面区微裂纹的产生与发展;但掺入较多的纤维也会使界面区增多导致混凝土孔隙率增加,进而使混凝土抗压强度降低。试验发现纤维掺量为3kg/m^3时,混凝土抗压强度最大。

This paper mainly studies the influence of basalt fiber incorporation on compressive strength, tensile strength and flexural properties of concrete, and analyzes the microstructure of basalt fiber concrete by SEM scanning electron microscope and porosity measurement. The test results show that the compressive, tensile and flexural strength of basalt fiber reinforced concrete are 28.2%, 22.7% and 15.3% respectively. The uniform distribution of basalt fiber can form a dense three-dimensional reticular structure in the concrete, greatly enhance the mechanical stability of concrete interface micro region, inhibit the generation and development of interfacial micro crack in concrete; but the incorporation of more fiber will make the interface area to increase porosity of concrete increases, and the compressive strength of concrete decreases. It is found that the compressive strength of concrete is the largest when the fiber content is 3 kg/m^3.