FB／PP混杂纤维对混凝土性能的影响

Effects of fibrous brucite/polypropylene hybrid fibers on properties of concrete

为提高混凝土的韧性,添加水镁石纤维(FB)与聚丙烯纤维(PP)的混杂纤维制成纤维混凝土材料.进行了混凝土的工作性和力学性能试验,研究了纤维对塌落度、抗压强度、弯拉强度及劈裂抗拉强度的影响.实验结果表明:FB/PP混杂纤维可以明显提高混凝土的弯拉强度及劈裂抗拉强度,且优于单一纤维增强的效果.在总纤维用量为0.5%的情况下,随PP纤维比例的增加,混凝土的塌落度及抗压强度减少,但劈裂抗拉强度上升.混凝土的弯拉强度先上升,后下降.弯拉强度最大值出现在PP∶FB=0.2%∶0.3%左右.随水灰比的降低,单一FB纤维对混凝土强度的增强效果一般呈加强趋势,而FB/PP混杂纤维对混凝土弯拉强度增强效果降低,对混凝土的劈裂抗拉强度的增强效果加强.

Effects of mixed fibers of fibrous brucite （FB） and polypropylene （PP） on the slump, compressive strength, flexural strength and splitting tensile strength of the concrete were investigated. Results show that FB/PP mixed fibers are better than the single FB fibers or PP fibers in the concrete reinforcement, especially in the improvement of the flexural and splitting tensile strengths of the concrete. With the dosage increase of PP fibers at the conditions of total fiber quantity of 0. 5 % in volume of the concrete, the slump and the compressive strength of the concrete decrease, the splitting tensile strength rises, and the flexural strength of concrete goes up at first, than goes down. The best flexural strength of the concrete appears at about the FB ： PP ratio of 0. 2% versus 0. 3%. With the decrease of water to cement ratio, the reinforcement effect of the FB/PP mixed fibers on the flexural strengthened. strength of the concrete is weakened and that to the splitting tensile strength is