砂胶比对混杂纤维增强水泥基复合材料力学性能的影响

Influence of sand-binder ratio on mechanical properties of hybrid fiber reinforced cementitious composites

采用标准砂制作新型混杂纤维增强水泥基复合材料试件,研究砂胶比对于复合材料弯曲、压缩力学性能的影响。试验结果显示,对于不掺纤维的素砂浆,0.50砂胶比下试件的力学性能更好;对于单掺钢纤维砂浆,0.45和0.55砂胶比下试件的力学性能相似,高于0.50砂胶比下的力学性能;对于钢纤维-PVA纤维两掺纤维增强砂浆,0.45砂胶比下试件的力学性能较好;对于钢纤维-PVA纤维-碳酸钙晶须三掺纤维增强砂浆,0.55砂胶比下试件的力学性能较好。此结果表明,新型混杂纤维体系中由于引入微观纤维,不仅改善了传统混杂纤维体系的增强效果,还可提高骨料的用量,从而有利于节省胶凝材料和提高复合材料体积稳定性。

The new hybrid fiber reinforced cement-based composite specimens were made by standard sand,the influence of sand-binder ratios on bending and compression mechanical properties of the composites were studied.The test results show that for the non-fibrous plain mortar,the mechanical properties of the test-piece are better at 0.50 sand-binder ratio.For the single-doped steel fiber mortar,the mechanical properties of the test-piece at 0.45 and 0.55 sand-binder ratio are similar and higher than those at the sand-binder ratio of 0.50.For the steel fiber-PVA fiber reinforced mortar,the mechanical properties of the test-piece at 0.45 sand-binder ratio are better.For the steel fiber-PVA fiber-calcium carbonate whisker reinforced mortar,the mechanical properties of the test-piece at 0.55 sand-binder ratio are better.The results show that the introduction of microscopic fibers in the new hybrid fiber system not only improves the reinforcing effect of the traditional hybrid fiber system,but also increases the dosage of aggregate,which is beneficial to save the cementitious material and improve the volume stability of the composite.