PVA纤维尾矿砂水泥基复合材料断裂能试验研究

Experimental investigation on the fracture energy of green PVA-tailings cement-based composites

通过10组40根预制切口EDFTCC梁的三点弯曲试验、电子显微镜微观扫描和RFPA软件的模拟,探究不同纤维掺量和不同细骨料种类对EDFTCC断裂能的影响。试验结果表明:PVA纤维能显著提高EDFTCC材料的断裂能,纤维最佳掺量建议为2%;纤维体积掺量不大于2%时,纤维分散性能良好,无结团现象,断裂能与纤维掺量呈线性增长关系,PVA纤维在基体中通过均匀分布能够与基体有效粘结,达到抑制裂缝数量和扩展的效果;尾矿砂制备EDFTCC的抗压强度和断裂能较天然砂的降低6%~10%,尾矿砂可部分替代天然砂制备PVA纤维尾矿砂水泥基复合材料。

On the base of three-point bending experiments of.a total 40 specimens in 10 groups,scanning election microscopy and RFPA system, the influencing rules of PVA fibers and aggregate types on the fracture energy of green PVA-tailings cementbased composites are investigated in this paper. Experimental results show that 2% of the fiber volume content is the best and the fracture energy of EDFTCC increases obvious linearly with the increment of PVA fiber. PVA fiber can be effective bonding with the substrate and has advantage of inhibition of crack development,no cluster phenomenon. The EDFTCC made by tail sand is reduced by 6%-10% compared with the natural sand on every performance. Tail sand can partly replace natural sand in preparation of PVA tail sand cement base composite materials.