Influence mechanism of basalt fibre on the toughness and microstructure of spray concrete
-
摘要: 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的影响规律,同时借助扫描SEM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SC,掺量为3 kg/m3及7.5 kg/m3的BF/SC抗弯试块韧性较好,其能量吸收能力分别为素SC的2.42倍和2.69倍。BF在SC内部具有较好的分散性,与SC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3 kg/m3的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及孔隙率增加,因此在本文实验条件下纤维掺量为3 kg/m3时BF/SC性能最好。Abstract: The effect of basalt fiber (BF) on the mechanical properties and toughness of basalt fiber reinforced spray concrete (BF/SC) was studied through the experiment. The microstructure of BF/SC was studied by 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 SC, the flexural strength of BF/SC with 3 kg/m3 and 7.5 kg/m3 are better, and are energy absorption capacity are 2.42 times and 2.69 times as high as the plain SC, respectively. BF has a good dispersion rate in the SC, and displays reasonable bonding within the SC substrate. A proper amount of BF effectively inhibits the formation of large volume pores, in which the proportion of the large pore size of 3 kg/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 is found to be 3 kg/m3.
-
Key words:
- basalt fiber /
- spray concrete /
- fiber content /
- toughness /
- microstructure
点击查看大图
计量
- 文章访问数: 875
- PDF下载量: 194
- 被引次数: 0