PVA纤维增强砖骨料再生混凝土数值模拟及尺寸效应研究  

Numerical Simulation and Size Effect Study on PVA Fiber-reinforced Brick Aggregate Recycled Concrete

作　　者：纪泳丞[1] 王大洋 贾艳敏[1] JI Yongcheng;WANG Dayang;JIA Yanmin(School of Civil Engineering and Transportation,Northeast Forestry University,Harbin 150040,China)

机构地区：[1]东北林业大学土木与交通学院,哈尔滨150040

出　　处：《材料导报》2025年第3期137-147,共11页Materials Reports

基　　金：国家自然科学基金面上项目(52370128)。

摘　　要：与刚性纤维相比,聚乙烯醇(PVA)纤维具有更细的直径和在混凝土中更加复杂的分布。采用两种建模方法分别建立了PVA纤维增强再生混凝土(FFF-BAC)的细观模型。其中,细观模型1(M1):水泥砂浆基质和PVA纤维结合视为一种特殊的工程水泥基复合材料(S-ECC),并与砖粗骨料(BA)、界面过渡区(ITZ)组合成FFF-BAC。细观模型2(M2):FFF-BAC为水泥砂浆、PVA、BA、ITZ组合成的四相材料。结合文献中S-ECC的试验结果,计算S-ECC的应力-应变关系。分别建立M1、M2,并与FFF-BAC单轴压缩试验结果进行比较,结果表明,M1与测试结果更加一致,各项参数的最大误差为11.0%。基于M1研究了FFF-BAC截面的损伤破坏过程,预测了BA掺量对抗压强度的影响,探究了不同尺寸的FFF-BAC的破坏模式,建立了可预测不同BA掺量的FFF-BAC抗压强度的尺寸效应公式。Compared to rigid fibers,PVA fibers have a finer diameter and a more complex distribution in concrete.Two modeling methods were used to establish a microscopic model of PVA fiber reinforced recycled concrete(FFF-BAC).Model 1(M1):considering the combination of cement mortar matrix and PVA fiber as a special engineering cement-based composite material(S-ECC),and combined with brick aggregate(BA)and interface transition zone(ITZ)to form FFF-BAC.Model 2(M2):FFF-BAC is considered as a four phase material composed of cement mortar,fiber,BA,and ITZ.M1 and M2 were established respectively,and compared with the uniaxial compressive strength test results of flexible fiber reinforced brick aggregate recycled concrete(FFF-BAC),to verify the accuracy of the two models.The results indicate that the M1 simulation is more consistent with the experimental results,with a maximum error of 11.0%for each parameter.The damage and failure process of FFF-BAC was studied,and the effect of BA content on compressive strength was predicted based on M1.The failure modes of different sizes of FFF-BAC were explored.Combining Bazant's size effect formula,a size effect formula for FFF-BAC considering BA content was established.

关 键 词：再生混凝土 砖骨料 细观模拟 抗压强度 尺寸效应 

分 类 号：TU501[建筑科学—建筑技术科学]