竖向荷载作用下预制叠合剪力墙收缩徐变效应研究

Investigation of shrinkage and creep effect of precast superimposed shear wall under axial load

为研究预制叠合剪力墙在竖向荷载作用下的收缩徐变效应,制作了一片小尺寸预制叠合剪力墙,对试件施加竖向荷载,得到了预制叠合剪力墙的收缩徐变反应.基于龄期修正有效弹性模量法(AEMM),考虑剪力墙结构长期收缩徐变效应引起的截面内力重分布,建立了长期竖向荷载作用下叠合剪力墙的收缩徐变及截面应力计算模型.经过比较,采用GL2000收缩徐变预测模型计算得到的结果与试验曲线吻合良好.在此基础上,比较了十年服役周期内,混凝土强度等级、纵向钢筋配筋率、环境湿度、初始加载龄期和轴压比对预制叠合剪力墙的收缩徐变效应的影响.

To investigate the shrinkage and creep effect of precast superimposed reinforced concrete shear wall(SRCSW)under axial load,one SRCSW specimen with reduced scale was manufactured.The micro strain developed by shrinkage effect and creep response of SRCSW specimen was documented when applied by the long term axial load.Considering the internal force redistribution caused by reinforcement during the long-term shrinkage and creep effect of SRCSW,the analytical model for calculating the stain response and the stress of cross-section were performed by using the age-adjusted effective modulus method(AEMM).The predicted result calculated by GL2000 model is in better agreement with the test result when compared to the other prediction models.Finally,the factors such as concrete grade,longitudinal reinforcement ratio,environmental humidity,initial loading age,as well as axial load ratio,which would affect the shrinkage and creep behavior of the analytical model under constant axial force for ten years,were discussed by parametric analysis.