Abstract: The informed methods of calculating concrete creep are analyzed, and a new calculation model of creep is proposed after synthesizing the research achievements of others.This method distinguishes elasticity of aggregate from hysteretic elasticity of mortar matrix; adopts Kelvin chain to display the aging action and the time of hysteresis on concrete;introduces time- ratio factor to take account of the response speed of time on hysteresis.Through the analysis in the case study, the results indicate that the variable process of concrete experiences hysteretic elasticity all time, but doesn' t do at the dead state;the time-ratio factor affects more obviously on concrete material characteristics under structure unloading or reloading conditions.

Key words: creep, recoverable creep, hysteretic/delayed elastic modulus, new method, time-ratio factor

摘要： 分析了已有的混凝土徐变计算方法,提出了一种新的徐变计算方法,该方法分离了以骨料为主的弹性和以砂 浆基质为主的滞弹性;采用了Kelvin链来模拟黏弹性并表现了混凝土的老化作用和滞后效应的时间;引入滞后效 应时间比例因子考虑时间对混凝土滞后效应的响应速度。实例分析结果表明:混凝土结构变化过程受其滞弹性影 响较大而最终状态几乎不受影响,时间比例因子在结构卸载或反复荷载的作用下对混凝土材料的特性影响明显。

关键词: 徐变, 徐变恢复, 滞弹模, 新方法, 时间比例因子