摘要
为研究聚丙烯粗纤维轻骨料混凝土梁弯曲荷载挠度曲线中的二次峰值问题以及拟合弯曲强度与纤维掺量间的定量关系,在轻骨料混凝土中掺入聚丙烯粗纤维,聚丙烯粗纤维掺量分别为0kg/m3、3kg/m3、6kg/m3和9kg/m3。采用四点弯曲试验,研究纤维掺量与轻骨料混凝土间的增强关系,同时引入二次峰值荷载模型,通过与其他文献数据对比,探讨弯曲荷载挠度曲线二次峰值现象的影响因素。结果表明,当聚丙烯粗纤维掺量为6kg/m3时,增强和增韧效果较好;弯曲强度和纤维掺量间拟合的定量关系式中ατ=3.360,与选取文献报道的ατ值相比,未出现二次峰值现象的ατ数值较小,而出现二次峰值荷载现象的ατ值均较大,较大的ατ值与弯曲荷载挠度曲线形成二次峰值荷载有关;对于聚丙烯纤维轻骨料混凝土梁弯曲荷载挠度曲线出现的二次峰值问题,二次峰值荷载模型给出了较好的解释。
In order to study the problem of secondary peak load of polypropylene fiber reinforced concrete beams in the bending deflection curve and the quantitative relationship between fitting flexural strength and fiber content,the lightweight aggregate concrete was mixed with polypropylene fiber,the polypropylene fiber content was 0 kg/m3,3 kg/m3,6 kg/m3 and 9 kg/m3,respectively.Four-point bending beam test was adopted to study the relationship between the fiber content and the lightweight aggregate concrete.By introducing secondary peak load model and by comparing with other literature data,the influential factors of the secondary peak load of the bending load deflection curve were discussed.The results show that when polypropylene fiber content is 6 kg/m3,bending toughness and flexural strength are better.In the fitting quantitative relationship between flexural strength and the fiber contentατ=3.360,compared with theατvalue in the selected literature,the value ofατwhich the secondary peak does not appear is smaller,while the value ofατwhich the secondary peak load appears is larger.The largerατvalue is related to the secondary peak load of the bending load deflection curve formation.The problem of secondary peak of polypropylene fiber lightweight aggregate reinforced concrete beam in the bending deflection curve can be better explained by secondary peak load model.
作者
牛建刚
刘江森
王佳雷
NIU Jiangang;LIU Jiangsen;WANG Jialei(School of Civil Engineering,Inner Mongolia University of Science and Technology,Baotou 014010;School of Civil Engineering,Central South University,Changsha 410083)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第14期2407-2411,2417,共6页
Materials Reports
基金
国家自然科学基金(51368042)
内蒙古自治区青年科技英才支持计划(NJYT-18-A06)
关键词
聚丙烯纤维
轻骨料混凝土梁
弯曲强度
二次峰值荷载模型
polypropylene fiber
lightweight aggregate reinforced concrete beam
flexural strength
secondary peak loadmodel
