混凝土徐变计算模型及其实用性评述

CALCULATION MODEL FOR CONCRETE CREEP AND ITS PRACTICAL APPLICATION

混凝土的徐变预测关系到结构长期性能的合理确定。目前已有多种混凝土徐变预测模型,为便于设计和研究,对各计算模型的影响因素进行了分析和综述。基于试验实测和参考文献结果,对各预测模型对高强混凝土徐变、早龄混凝土的压缩/拉伸徐变的实用性进行了评价。结果表明:JTG D62―2012和GL 2000模型较适用于高强混凝土;GL 2000模型较适用于早龄混凝土的压缩和拉伸徐变,但压缩徐变误差超过26.4%,拉伸徐变误差大于46.1%,其他预测模型的误差不可接受。因此,既有的混凝土徐变模型不适用于早龄混凝土的拉伸与压缩徐变预测。如要对早龄结构进行受力分析,需采用反映早龄混凝土结构拉伸/压缩徐变特性的徐变模型。

The concrete creep prediction is related to the reasonable determination of the long-term performance of a structure. At present, a variety of concrete creep prediction models have been developed. In order to facilitate design and research, the influencing factors of various calculation models are analyzed and summarized. Based on the experimental measurements and reference results, the applicability of various prediction models for high strength concrete creep and early age concrete compression/tensile creep is evaluated. The results showed that： JTG D62 2012 and GL 2000 model is more suitable for high strength concrete. GL 2000 model is suitable for early age concrete compressive/tensile creep, but the compression creep error exceeds 26.4%, the tensile creep error is greater than 46.1%, and the error of the other prediction models are not acceptable. Therefore, the existing creep model of concrete is not suitable for early age concrete tension and compression creep prediction. For the analysis of an early age structure, the creep model which reflects the tensile/compression creep characteristics of early age concrete structures is needed.