聚丙烯纤维和粗骨料对超高性能混凝土抗拉强度的影响研究  

Effects of Polypropylene Fiber and Coarse Aggregate on Tensile Strength of Ultra High Performance Concrete

作　　者：陈倩[1] CHEN Qian(Wuhan University,Wuhan,Hubei 430072,China)

机构地区：[1]武汉大学

出　　处：《水利与建筑工程学报》2019年第6期113-116,199,共5页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金重点项目资助(51738011)

摘　　要：向超高性能混凝土中掺入适量粗骨料,可在不降低其力学性能的前提下有效减少胶凝材料的用量,降低其成本。同时,为改善混凝土固有的抗拉强度低的缺陷,将聚丙烯纤维和钢纤维混杂掺入混凝土中可取得较好成果。考虑聚丙烯纤维体积掺量和长径比、粗骨料掺量3个因素,设计并制作了18组共54个超高性能混凝土试块,通过试验研究分析聚丙烯纤维特征参数和粗骨料掺量对含粗骨料超高性能混凝土劈裂抗拉强度的影响规律。结果表明,试验参数范围内,随着聚丙烯纤维体积掺量的增加,UHPC的劈裂抗拉强度呈现先减后增再减的规律;随着聚丙烯纤维长径比的增大,呈现先减后增的规律;聚丙烯纤维最佳配比为体积掺量0.10%,长径比167;掺入质量分数为15%的粗骨料不会降低UHPC的劈裂抗拉强度,但当粗骨料掺量提高到30%时,UHPC的劈裂抗拉强度降低明显。The amount of cementitious materials can be effectively reduced by adding appropriate coarse aggregate into UHPC without reducing its mechanical properties.Meanwhile,in order to improve the inherent weakness of concrete in tensile strength,mixing polypropylene fiber and steel fiber into concrete can get better results.In consideration of three factors of mass fraction(0%,15%,30%)of coarse aggregate,aspect ratio(167,280,396)and volume fraction(0%,0.05%,0.10%,0.15%)of polypropylene fiber,18 batches specimens of UHPC were poured.Splitting tensile test was conducted to analyze the tensile strength of UHPC,focusing on the effect of polypropylene fiber parameters and mass fraction of coarse aggregate on the splitting tensile strength.Results of the test showed that,in the studied range,the splitting tensile strength of UHPC decreases first then increases and then decreases again with the increase in volume fraction of polypropylene fiber;with the increase in aspect ratio of polypropylene fiber,the splitting tensile strength decreases first and then increases;the optimum polypropylene fiber proportion is with an aspect ratio of 167 and a volume fraction of 0.10%;the addition of coarse aggregate with a mass fraction of 15%do not have any negative effects on the splitting tensile strength of UHPC,but when the mass fraction of coarse aggregate increases to 30%,the splitting tensile strength of UHPC decreases significantly.

关 键 词：超高性能混凝土(UHPC) 聚丙烯纤维 粗骨料 抗拉强度试验 

分 类 号：TU528.572[建筑科学—建筑技术科学]