配筋对混凝土徐变的影响分析

Analysis of reinforcement influence on concrete creep

基于龄期调整的有效模量法和内力重分布机理,引入钢筋修正系数预测钢筋混凝土的徐变并且推导出相应的计算公式。通过对相关数据进行拟合分析,验证钢筋修正系数的有效性和实用性。在此基础上,提出基于现行公路桥涵设计规范徐变模型的配筋混凝土徐变计算公式,并分析老化系数、配筋率、加载龄期等参数对徐变的影响。研究结果表明:配筋对混凝土徐变具有抑制作用;当配筋率很小时,配筋对混凝土的相对抑制作用最强,随着配筋率增大,相对抑制作用逐渐降低;加载龄期和配筋对混凝土徐变的影响有叠加作用,并且这种叠加作用不只是简单的线性叠加。

Based on the age-adjusted effective modulus method（AEMM） and internal force redistribution mechanism,the reinforced correction coefficient was introduced to predict the creep of reinforced concrete and deduce the corresponding calculation formula. The validity and practicability of the reinforced correction coefficient were verified by fitting analysis of the related data. The calculation formula of reinforced concrete creep based on the current code for design of highway reinforced concrete and prestressed concrete bridges and culverts were proposed. Furthermore, the effects of different parameters such as aging coefficient, reinforcement ratio and loading age were analyzed. The results show that reinforcement exerts the inhibitory effect on concrete creep. The inhibitory effect is the strongest when the reinforcement ratio is small and it gradually weakens when the reinforcement ratio increases. Loading age and reinforcement exert additive influences on concrete creep, which is not a simple linear superposition.