【摘要】 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。更多还原

【Abstract】 Combined with the construction of Jinghong Canal Bridge of Jiangliu Highway,shrinkage and creep property of the cast-in-situ high performance concrete of bridge girder was researched.The results showed early shrinkage and creep development of the high performance concrete was relatively rapid,and creep tended to be stable 120 days later.With the admixture increasing,shrinkage and creep of the concrete were reduced.Meanwhile, early creep rate deceased.Similar results applied to the reduction of sand rate and water-cement ratio.Based on creep prediction models both at home and abroad,hyperbolic power function and exponential function model were put forward,taking the influence of material parameter and environmental factors on shrinkage and creep into consideration.In accordance with the model,concrete creep formula was given out and would provide a relatively scientific basis for practical prediction of concrete creep.更多还原