【摘要】 在聚羧酸减水剂控制新拌混凝土坍落度条件下研究了添加矿物掺合料和聚丙烯纤维对混凝土开裂性的影响。结果表明:在20%～40%掺量范围,粉煤灰或矿渣粉均能明显提高混凝土抗裂性能;粉煤灰提高混凝土抗裂性能的效果优于矿渣粉,二者复掺能显著提高混凝土的抗裂性能。聚丙烯纤维的长度对混凝土总开裂面积影响相对较小,但对裂缝宽度影响较大,纤维长度为粗集料最大粒径的3/5时,混凝土抗裂性能最佳。根据本实验结果,聚丙烯纤维的掺量宜选择在0.9～1.2 kg/m3。更多还原

【Abstract】 Effect of mineral admixture and polypropylene fiber on concrete crack property was investigated with polycarboxylate superplasticizer(PCA) controlling the slump of fresh concretes.The results showed that fly ash(FA)or blast furnace slag(BFS) could improve crack resistance of concrete significantly in the range of 20% to 40%.Crack resistance of concrete was improved better by FA than BFS when they were applied at the same content.The addition of the combination of FA and BFS was better in the improvement of concrete crack resistance.The length of polypropylene fiber(PPF) had less effect on total cracking area of concrete,but had greater effect on crack width of concrete.Crack resistance of concrete was the best when fiber length was 3/5 of the maximum particle size of coarse aggregate.Based on the results of this experiment,the optimum content of PPF was 0.9-1.2 kg/m3.更多还原