摘要
为研究不同龄期再生混凝土损伤性能,以龄期、取代率为变量设计了45个试件进行直剪试验,获取了再生混凝土直剪破坏形态及荷载-位移曲线,分析了取代率、龄期对试件损伤的影响,并建立了分段式损伤本构模型。研究结果表明,7天龄期再生混凝土直剪破坏以界面破坏为主,在14天龄期、28天龄期转换为界面破坏、粗骨料剪断共存;直剪作用下再生混凝土荷载-位移曲线可分为线性段、上升段及下降段三段,与破坏过程中弹性阶段、弹塑性阶段及塑性阶段对应;取代率低的再生混凝土试件损伤出现时间相对较晚,28天龄期再生混凝土损伤出现最早但发展速度慢;使用分段式模型建立再生混凝土直剪全过程本构曲线,并给出本构曲线参数取值表,拟合曲线与实测曲线吻合良好。
In order to study the damage performance of recycled aggregate concrete at different ages,45 specimens were designed for direct shear tests,considering the effects of age and replacement ratio,and the direct shear damage morphology and load-displacement curves of recycled aggregate concrete were obtained,and the effects of replacement ratio and age on the damage of specimens were analyzed,and a segmental damage constitutive model was established.The results showed that the direct shear damage of recycled aggregate concrete at the age of 7 days was dominated by interface damage,and the coexistence of interface damage and coarse aggregate shear at the age of 14 days and 28 days;the load-displacement curves of recycled aggregate concrete under direct shear can be divided into linear,ascending and descending segments,which correspond to the elastic,elasto-plastic and plastic phases of the damage process;the damage of recycled aggregate concrete specimens with low replacement rate appears relatively late,and the damage of recycled aggregate concrete at the age of 28 days appears earliest but develops slowly;the segmental model is used to establish the intrinsic structure curve of recycled aggregate concrete in direct shear,and the table of parameters of the intrinsic structure curve is given,and the fitted curve is in good agreement with the measured curve.
作者
晏方
邱新生
付善春
杨子泉
郑振斌
Yan Fang;Qiu Xinsheng;Fu Shanchun;Yang Ziquan;Zheng Zhenbin(School of Civil Engineering,Xinyang University,Xinyang,Henan 464000,China;Xinyang Key Laboratory of Assembly Building,Xinyang University,Xinyang,Henan 464000,China;Shenfei Construction Engineering Co.Ltd,Xinyang,Henan 464000,China)
出处
《黑龙江工业学院学报（综合版）》
2023年第7期137-144,共8页
Journal of Heilongjiang University of Technology(Comprehensive Edition)
基金
河南省高等学校重点科研项目(项目编号:23B560013)
信阳学院校级科研项目(项目编号:2022-XJLYB-016)。
关键词
再生混凝土
直剪
龄期
损伤本构
recycled aggregate concrete
direct shear
age
damage constitutive
