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结合江苏省江六高速公路京杭运河大桥工程建设,对大桥主梁现浇高性能混凝土进行收缩和徐变试验,结果表明:高性能混凝土前期收缩和徐变发展较快,120d以后徐变趋于稳定。随掺合料增加,混凝土的收缩和徐变性能降低,并且早期徐变速率减小;减小砂率、水胶比也降低了收缩和徐变。在国内外徐变预测模型的基础上,提出双曲幂函数和指数函数模型,该模型考虑了材料参数和环境因素对收缩徐变的影响,并按照该模型拟合出混凝土徐变度计算公式,为实际工程中混凝土徐变性能预测提供了科学依据。
Combined with the construction of Jinghang Canal Bridge of Jiangli Expressway in Jiangsu Province, shrinkage and creep tests on the cast-in-situ HPC of the main girder of the bridge are carried out. The results show that the shrinkage and creep of high performance concrete develops rapidly and the creep tends to increase after 120 days stable. With the increase of admixture, the shrinkage and creep properties of concrete decrease, and the early creep rate decreases; reducing the sand rate, water-cement ratio also reduces the shrinkage and creep. Based on the prediction models of creep at home and abroad, the hyperbolic power function and exponential function model are proposed. The model takes into account the influence of material parameters and environmental factors on the shrinkage and creep. According to the model, the creep degree of concrete is calculated , Which provides a scientific basis for the prediction of creep properties of concrete in practical engineering.