摘要
黏结滑移性能是再生混凝土技术应用于工程实际的一项重要课题。考虑再生粗骨料取代率(30%、50%、70%)和再生混凝土强度等级(C20、C40)2个参数,制作5组再生混凝土试件进行中心拔出试验。得到不同种类再生混凝土的荷载-滑移曲线,曲线可分为微滑、滑移、劈裂、破碎、残余5个阶段。定义了初始黏结滑移模量E0及峰值黏结滑移割线模量Eu,E0/Eu数值越大,混凝土黏结性能越好。当混凝土强度等级相同,再生粗骨料取代率小于70%时,黏结强度随取代率的增大而增大;当取代率相同,黏结强度随混凝土强度等级增加而增大。基于试验与理论分析,给出了再生粗骨料取代率与极限黏结强度的方程以及黏结滑移本构关系方程,模型结果与试验结果吻合良好。
Bond-slip behavior is an important project of recycled concrete in applying to engineering practice.Considering 2 parameters which are recycled coarse aggregate replacement ratio(30%,50%,70%)and recycled concrete strength grade(C20,C40),5 sets of recycled concrete specimen are made to carry out central pull out test.The load-slip curves of different recycled concrete are recorded and these curve′s trend can be divided into 5 stages micro-slipping,slipping,splitting,crushing and residual.Initial bond slip modulus E0 and peak bond slip secant modulus Eu are defined.The greater the value E0/Eu,the better the concrete′s bonding performance.When the strength grade of concrete is same and the recycled coarse aggregate replacement ratio is less than 70%,concrete′s bond strength increase with replacement ratio.When replacement ratio is same,the bond strength increase with strength grade.On the basis of experimental theory analysis,the relation equation of recycled coarse aggregate replacement ratio with bond strength and bond-slip constitutive equation are given.The model result agree well with test result.
作者
何振军
韩秀
张晓洁
张学生
HE Zhenjun;HAN Xiu;ZHANG Xiaojie;ZHANG Xuesheng(College of Civil Engineering,North China University of Technology,Beijing 100144,China;College of Civil Engineering and Architecture,Dalian University,Dalian 116622,China;Beijing Urban Construction Group Co.,Ltd.,Beijing 100000,China)
出处
《混凝土》
CAS
北大核心
2019年第2期35-39,43,共6页
Concrete
基金
北方工业大学2018年毓优团队项目(201839)
关键词
再生混凝土
黏结滑移
拉拔
取代率
强度等级
recycled concrete
bond-slip
pull-out
replacement ratio
strength grade
