摘要
为考虑型钢对混凝土内部湿度扩散的阻碍作用,结合纤维模型和B3模型提出最大湿度扩散系数和表面交换系数求解公式,采用纤维模型法分析内置方钢管混凝土柱干燥收缩变形的发展规律及主要影响因素,并在B3收缩预测模型中引入修正系数,基于参数分析提出了内置方钢管混凝土柱的干燥收缩预测模型,通过试验验证收缩预测模型和湿度参数公式的可靠性。分析和试验结果表明:最大湿度扩散系数取决于混凝土强度,而表面交换系数与构件截面尺寸有关;由于方钢管阻碍了混凝土内部的湿度扩散,内置方钢管混凝土柱的收缩变形和发展趋势显著低于常规钢筋混凝土柱的;与B3模型相比,提出的收缩预测模型可有效考虑型钢对混凝土湿度分布的影响,其对预测内置方钢管混凝土柱的干燥收缩变形具有更高的精度。
To consider the hindrance of section steel on the moisture diffusion in concrete,the formulas of the maximum moisture diffusion coefficient and the surface factor were proposed based on the fiber model and the B3 model.The development law and main influencing factors of the dry shrinkage of square steel reinforced concrete(SSRC)columns were analyzed by the fiber model,and the drying shrinkage prediction model of SSRC columns was proposed by introducing modified coefficients into the B3 model.Then,the effectiveness of the proposed shrinkage prediction model and moisture parameter formulas was verified by experiments.Analysis and test results show that the maximum moisture diffusion coefficient depends on the concrete strength,while the surface factor is related to the column size.The drying shrinkage of SSRC columns is significantly lower than that of reinforced concrete(RC)columns,resulting from the hindrance of square steel on the moisture diffusion.Moreover,compared with the B3 model,the proposed shrinkage prediction model considering the effect of section steel has higher prediction accuracy on the drying shrinkage of SSRC columns.
作者
吴杰
魏霄
杨永华
朱大宇
WU Jie;WEI Xiao;YANG Yonghua;ZHU Dayu(College of Civil Engineering,Tongji University,Shanghai 200092,China;College of Civil Engineering,Shanghai Normal University,Shanghai 200234,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2021年第S02期339-347,共9页
Journal of Building Structures
基金
国家自然科学基金项目(51878475)
关键词
型钢混凝土柱
方钢管
干燥收缩
模型试验
B3模型
湿度扩散系数
表面交换系数
steel reinforced concrete column
square steel tube
drying shrinkage
model test
B3 model
moisture diffusion coefficient
surface factor
