摘要
为研究无黏结预应力再生混凝土叠合梁构件的受弯性能,以再生混凝土在叠合梁中的位置、叠合层高度、构件的配筋率为参数,对1根预应力普通混凝土整浇梁、1根预应力再生混凝土整浇梁和6根预应力再生混凝土叠合梁构件进行弯曲加载试验,分析了试验梁构件的受力过程和破坏形态,探讨了各参数对试验梁构件极限承载力的影响。基于试验数据,对承载力极限状态下无黏结预应力再生混凝土叠合梁承载力进行了验证。结果表明:当再生混凝土应用于预应力叠合梁受弯构件时,跨中截面沿高度的应变变化规律与截面平截面假定一致,普通混凝土与再生混凝土之间有较好的相互作用,能够协同受力,共同变形;无黏结预应力钢绞线的应力增量曲线为三折线,当再生混凝土位于预制层时,配筋相同条件下,预制层高度增加会延缓梁内纵向受力普通钢筋受拉屈服;相同预制层高度时,提高纵向钢筋强度可以有效提高梁的性能;与普通混凝土梁相比,再生混凝土梁裂缝数量相对较多,达到极限荷载时裂缝延伸高度相对较小;再生混凝土位于叠合层时,裂缝数量有所增加,裂缝间距相对较小;随着预制层高度和构件配筋率增加,试验梁平均裂缝间距逐渐增大。
In order to study the flexural behavior of unbonded prestressed recycled concrete composite beam members,the position of recycled concrete in the composite beam,the height of the composite layer,and the reinforcement ratio of the members were taken as parameters,one prestressed ordinary concrete cast-in-place beam,one prestressed recycled concrete cast-in-place beam and six prestressed recycled concrete composite beam members were subjected to bending loading tests.The stress process and failure modes of the test beam members were analyzed,and the effects of various parameters on the ultimate bearing capacity of test beam members were discussed.Based on the experimental data,the bearing capacity of the unbonded prestressed recycled concrete composite beam under the ultimate bearing capacity state was verified.The results show that when recycled concrete is applied to the bending members of prestressed composite beam members,the strain change law along the height of the mid-span section is consistent with the assumption of the plane section,and there is a good interaction between ordinary concrete and recycled concrete,so they can cooperate to force and deformation.The stress increment curve of the unbonded prestressed steel strand is a three-fold line.When the recycled concrete is located in the precast layer,under the same condition of reinforcement,the increasing of the precast layer height will delay the tensile yield of the ordinary longitudinal stressed steel bars in the beam.With the same precast layer height,improving the strength of the longitudinal steel bars can effectively improve the performance of the beam.Compared with ordinary concrete beams,the number of cracks in recycled concrete beams is relatively large,and the crack extension height is relatively small when reaching the ultimate load.When the recycled concrete is located in the laminated layer,the number of cracks increases,and the crack spacing is relatively small.With the increases of precast layer height and member reinforcement ratio,the average crack spacing of test beams gradually increases.
作者
程东辉
王楷文
宋超
CHENG Dong-hui;WANG Kai-wen;SONG Chao(School of Civil Engineering,Northeast Forestry University,Harbin 150040,Heilongjiang,China)
出处
《建筑科学与工程学报》
CAS
北大核心
2022年第2期52-60,共9页
Journal of Architecture and Civil Engineering
基金
哈尔滨市科技创新人才研究专项基金项目(2012RFXXS111)
中央高校基本科研业务费创新团队与重大项目培育资金项目(2572016EBC1)。
关键词
预应力叠合梁
再生混凝土
静力试验
受弯性能
极限承载力
prestressed composite beam
recycled concrete
static test
flexural behavior
ultimate bearing capacity
