玄武岩纤维对喷射混凝土力学性能及微观结构影响机制

《复合材料学报》优先在线发表论文。

摘  要：本文通过力学性能实验研究了玄武岩纤维（BF）对玄武岩纤维喷射混凝土（BF/SC）基本力学性能及韧性影响规律，同时借助扫描电子显微镜（SEM）以及核磁共振（NMR）实验对BF/SC的微观结构进行研究。结果表明：添加BF可以显著提高BF/SC的抗压强度、劈裂抗拉强度和抗弯强度；相较于素喷射混凝土，掺量为3kg/m3以及7.5kg/m3的BF/SC抗弯试块韧性较好，其能量吸收能力分别为素喷射混凝土的2.42倍和2.69倍。BF在混凝土内部具有较好的分散性，与喷射混凝土基体界面粘结性较好。适量BF有效地抑制了大体积孔隙的生成，其中掺量为3kg/m3 BF/SC大孔径孔隙占比仅为0.25%，但过多BF掺入会导致纤维结团以及孔隙率增加，因此在本文实验条件下纤维掺量为3kg/m3时喷射混凝土性能最好。

关键词：玄武岩纤维；喷射混凝土；纤维掺量；力学性能；微观结构

Abstract: The effect of basalt fiber (BF) on the mechanical properties and toughness of basalt fiber reinforced spray concrete (BF/SC) is studied through experimentation. The microstructure of BF/SC was studied by scanning electron microscope (SEM) and nuclear magnetic resonance (NMR).The results show that the compressive strength, splitting tensile strength and flexural strength of BF/SC are significantly increased by adding BF. Compared to the plain shotcrete, the flexural strength of BF/SC with 3kg/m3 and 7.5kg/m3 was better, and its energy absorption capacity is 2.42 times and 2.69 times as high as the plain shotcrete, respectively. BF have a good dispersion rate in the shotcrete, and displayed reasonable bonding within the shotcrete substrate. A proper amount of BF effectively inhibits the formation of large volume pores, in which the proportion of the large pore size of 3kg/m3 BF/SC is only 0.25%, and the addition of excessive BF leads to an increase of fiber agglomeration and porosity. At the same time, the optimum content of fiber was found to be 3kg/m3.

Keywords: basalt fiber; spray concrete; fiber content; toughness; microstructure

作者：焦华喆等，河南省地下空间开发及诱发灾变防治国际联合实验室 河南理工大学，焦作

通讯作者：陈新明，河南省地下空间开发及诱发灾变防治国际联合实验室 河南理工大学，焦作

全文详见中国知网学术期刊优先数字出版。