摘要
为了研究钢纤维全再生粗骨料混凝土的力学性能,以钢纤维体积掺量为变化参数,设计制作了36个试件进行立方体与圆柱体单轴抗压及棱柱体抗折试验。观察了试件的破坏过程及形态,获取了圆柱体单轴受压的应力-应变全曲线及棱柱体抗折的荷载-跨中挠度曲线,分析了钢纤维掺量对全再生粗骨料混凝土抗压及抗折的力学性能影响,并进行了各强度指标换算。结果表明:随着钢纤维掺量的增加,不同加载制度下立方体抗压试件的破坏形态整体性更好而圆柱体更差,钢纤维棱柱体抗折试件破坏时跨中裂缝在5~8 mm;掺钢纤维为提高全再生粗骨料混凝土抗压强度时建议掺量为1.5%;与不掺纤维相比,不同钢纤维掺量对圆柱体抗压强度影响不明显,部分试件有所降低,破坏时的峰值应变整体增大;随着钢纤维掺量的增加,圆柱体的静压弹性模量先增大后减小,其轴压韧性比逐渐增大;掺钢纤维不影响全再生粗骨料混凝土的初始韧性,峰值后的残余弯曲韧性随纤维掺量的增加不断增大。
In order to study the mechanical properties of steel fiber reinforced fully recycled coarse aggregate concrete,a total of 36 specimens with varying parameters of volume ratio of steel fiber were designed and manufactured for uniaxial compression test of cube and cylinder and bending test of prism.The failure process and modes were observed.And the stress-strain curves of the cylinder under uniaxial compression and the load-deflection curves of the prism under bending were obtained respectively.The influence of vol ume ratio of steel fiber on mechanical properties of recycled coarse aggregate concrete under uniaxial compression and bending was analyzed.Then the strength indexes were converted.The test results show that with the increase of volume ratio of steel fiber,under different loading systems,the integrity of the failure mode of the cube compression specimens is better,but the cylinder is worse.When the steel fiber reinforced prismatic specimens are damaged,the mid span cracks are 5-8 mm.In order to improve the cube compressive strength of fully recycled coarse aggregate concrete with steel fiber,the recommended volume ratio of steel fiber is 1.5%.Compared with the specimens without fiber,the influence of different volume ratio of steel fiber on the compressive strength of cylinder is not obvious,some of the specimens are reduced,a nd the peak strain at failure increases as a whole.With the increase of volume ratio of steel fiber,the static pressure elastic modulus of the cylinder first increases and then decreases,and the axial compression toughness ratio of cylinder under uniaxial compression gradually increases.Steel fiber does not affect the initial toughness of fully recycled coarse aggregate concrete,and the residual flexural toughness increases with the increase of volume ratio of steel fiber.
作者
苏炜炜
陈宗平
廖浩宇
周星宇
SU Weiwei;CHEN Zongping;LIAO Haoyu;ZHOU Xingyu(College of Civil Engineering and Architecture,Guangxi University,530004 Nanning,China;College of Civil Engineering and Architecture,Nanning University,541699 Nanning,China;Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education,Guangxi University,530004 Nanning,China)
出处
《应用力学学报》
CAS
CSCD
北大核心
2022年第5期947-957,共11页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金资助项目(No.51578163)
八桂学者专项(No.桂政发【2019】79)
南宁市科学研究与技术开发计划重大项目(No.20223024)
广西重点研发计划资助项目(No.桂科AB21220012)
广西科技基地和人才专项资助项目(No.桂科AD21075031)。
关键词
钢纤维
全再生粗骨料
单轴受压
抗折
强度换算
steel fiber
fully recycled coarse aggregate
uniaxial compression
flexura
strength index conversion
