摘要
为研究纤维对高强再生骨料混凝土梁抗弯性能的影响,以粗骨料类型、纤维种类、纤维掺入方式和纤维体积掺量为变化参数完成了8根混凝土梁的四点弯曲试验,分析了不同参数对高强再生骨料混凝土梁破坏特征、裂缝宽度、挠度、开裂荷载、抗弯承载力和延性的影响。试验结果表明:掺入纤维的高强再生骨料混凝土梁和未掺入纤维的高强再生骨料混凝土梁破坏特征与高强天然骨料混凝土梁相似,均经历了弹性阶段、带裂缝工作阶段和破坏阶段;高强再生骨料混凝土梁的开裂荷载、刚度和变形性能较高强天然骨料混凝土梁均有所降低,且裂缝较宽,挠度较大;掺入聚乙烯醇/钢纤维有效抑制了裂缝的产生和进一步扩展,提高了开裂荷载,增强了变形性能;单掺聚乙烯醇纤维可使开裂荷载和延性显著提高,但抗弯承载力基本没有变化;单掺钢纤维与混掺聚乙烯醇-钢纤维均使再生骨料混凝土梁力学性能有所提高;与未掺纤维的再生骨料混凝土梁相比,混掺0.1vol%聚乙烯醇-1.5vol%钢纤维后,开裂荷载、抗弯承载力和延性分别提高了60.0%、4.2%和20.1%;利用规程对纤维增强再生骨料混凝土梁进行抗弯承载力计算,计算结果与实测结果吻合较好。
To study the flexural performance of fiber reinforced high-strength recycled aggregate concrete beams(FRHRACB),four-point flexural experimental investigates of eight concrete beams were completed.The main parameters were coarse aggregate types,types of fiber,fiber mixing methods and volumetric fiber dosage.The influences of different parameters on the failure modes,crack width,deflection,crack load,flexural capacity and ductility of recycled coarse concrete beams were analyzed.The experimental results show that the failure modes of recycled aggregate concrete beams with or without fiber are similar to those of natural aggregate concrete beams,which have an elastic stage,a working stage with cracks and a failure stage.The cracking load,stiffness and deformation performance of recycled aggregate concrete beams are lower than those of natural aggregate concrete beams.Furthermore,wider cracks and bigger deflection are found for recycled concrete beams.With the addition of polyvinyl alcohol/steel fibers,the generation and further expansion of cracks in recycled aggregate concrete beam are restrained.Meanwhile,the cracking load is increased,and the deformation performance is enhanced.Singlemixed polyvinyl alcohol fibers have obvious positive influence on the cracking load and ductility of recycled aggregate concrete beams,but almost no effect on the flexural capacity.However,single-mixed steel fibers and mixed polyvinyl alcohol-steel fibers improve the flexural performance of recycled aggregate concrete beams significantly.Compared with the recycled aggregate concrete beams without fiber,when 0.1vol%polyvinyl alcohol-1.5vol%steel fiber are added,the cracking load,the flexural capacity and ductility are improved by 60.0%,4.2%and 20.1%,respectively.According to the standard,the flexural bearing capacity of recycled aggregate concrete beams was calculated,and the calculation results agree well with the test results.
作者
牛海成
高锦龙
李博涵
范玉辉
王永贵
NIU Haicheng;GAO Jinlong;LI Bohan;FAN Yuhui;WANG Yonggui(School of Civil Engineering,Henan Polytechnic University,Jiaozuo 454000,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2022年第11期5499-5511,共13页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(U1904188)
河南省自然科学基金(182300410247)。
关键词
再生骨料混凝土梁
静力试验
聚乙烯醇纤维
钢纤维
延性
抗弯性能
recycled aggregate concrete beams
static experiment
polyvinyl alcohol fiber
steel fiber
ductility
flexural performance
