纤维对复合矿物掺合料混凝土强度影响的研究

Study on the effect of fiber on the strength of composite mineral admixture concrete

采用单掺与正交的方法,研究了玄武岩纤维与聚丙烯纤维对混凝土7 d和28 d抗压强度的影响,分析了两种纤维分别提升混凝土强度的机理。结果表明,玄武岩纤维与聚丙烯纤维限制早期混凝土内部微裂缝的产生,二者最佳掺量分别为0.1%和0.15%,此时抗压强度相较于对照组,分别提升了13%和9.5%。正交实验得出三因素对混凝土抗压强度影响顺序依次是玄武岩纤维>矿物掺合料>聚丙烯纤维,此时正交实验最佳配合比为:粉煤灰∶矿渣=1∶1.25(球磨15 min),玄武岩纤维掺量0.125%,聚丙烯纤维掺量0.175%,28 d混凝土的抗压强度为68.6 MPa。

The effects of basalt fibers and polypropylene fibers on the 7 d and 28 d compressive strength of concrete were investigated by using single-mixing and orthogonal methods,and the mechanisms of the two types of fibers to enhance the strength of concrete were analyzed,respectively.The results showed that basalt fibers and polypropylene fibers limited the generation of microcracks within the concrete at early stage,and the optimal dosage of the two was 0.1%and 0.15%,respectively,at which time the compressive strength was improved by 13%and 9.5%,respectively,compared with the control group.Orthogonal test concluded that the three factors on the compressive strength of concrete in the order of basalt fiber→mineral admixture→polypropylene fiber,at this time,the best orthogonal test ratio is:fly ash∶slag=1∶1.25(ball milled for 15 min),basalt fiber dosage of 0.125%,polypropylene fiber dosage of 0.175%,the 28 d compressive strength of concrete is 68.6 MPa.