不同长度玄武岩纤维改性水泥性能研究

Study on the of Cement Modified with Different Lengths of Basalt Fiber

玄武岩纤维(BF)合理的长度及掺量对水泥基复合材料的工作性能及力学性能有显著影响。试验对比研究了长度为3、6、9 mm BF,当掺量为0.2%、0.4%、0.6%、0.8%时,BF水泥基复合材料的流动度及抗折、抗压性能的变化,并探讨了试块在7 d、14 d热稳定性能的变化。结果表明,BF越长,掺量越高,BF水泥基复合材料流动度显著下降。与空白试块的流动度267 mm相比,掺0.8%9 mm BF水泥基材料的流动度下降至207 mm。水泥基中加入合理掺量与长度的BF时,能显著提高水泥基复合材料的抗拉、抗压强度。当长度为9 mm BF掺量小于0.4%时,BF水泥基复合材料的抗折、抗压强度综合性能最优。此外,BF水泥基复合材料在7 d和14 d具有类似的热降解行为,且14 d试块的热稳定性优于7 d试块的热稳定性。同样龄期下,与空白试块相比,BF水泥基试块的热稳定性明显提升。

The reasonable length and mass fraction of basalt fiber(BF)in the cement have a significant impact on the the fluidity and physical properties.The effects of BF length(3 mm,6 mm,9 mm),with mass fraction(0.2%,0.4%,0.6%,0.8%)on fluidity,flexural and compressive strength of BF cement based composites have been studied in this case.In addition,the thermal stability of samples in 7 d and 14 d has also been investigated,respectively.It could be found that the fluidity of the BF cement motars gradually decrease with the increase of the length and the mass fraction of BF.Compared with Blank sample(267 mm),the fluidity of cenemt motar with 0.8%BF of 9 mm length is decreased to 207 mm.The variation law of the influence of fiber length and fiber mass fraction on the flexural and compressive strength of BF cement based composite are revealed.The results show that the flexural and compressive strength of the BF cement based composites could be increased within the reasonable mass fraction and length of BF.When the mass fraction of BF of 9 mm length is less than 0.4%,the BF cement based composites have the optimal comprehensive performance of the flexural and compressive strength.In addition,the BF cement based composites exhibit the similar thermal degradation behavior within 7 d and 14 d.Compared with Blank sample,the thermal stability of BF cement based composites could be significantly improved after incorporating a certain amount of BF into the cement matrix.