Concrete shrinkage and creep effect prediction model and the influence factors analysis

摘要

It is a complex problem that forecast and control the shrinkage and creep of concrete and influence on the performance of the structures. Through the comparison of all kinds of common model, the article have also analysed the main influence factors about the concrete shrinkage and creep effect. The results showed that JTJ 85 model for shrinkage and creep effect tends to conservative calculation; the creep coefficient and shrinkage strain of JTG D62 model and the CEB-FIP model were basically consistent; and ACI 209 model underestimated the concrete shrinkage and creep effect. Theoretical depth of components was more sensitive to concrete shrinkage strain, and creep coefficient was smaller sensitivity; The effect of concrete creep increases with the decreasing of age at loading, when age of loading percentage increased from three to 28 days, the concrete creep effect of the terminal value reduced about 80%; The influence of environment average relative humidity on shrinkage and creep effect is more sensitive, when environment average relative humidity increased from 50% to 80%, creep coefficient nearly reduced about 30%, and shrinkage strain decreased 50%, in comparison, the influence of environment relative humidity chance on the concrete shrinkage effect is greater than that on creep effect.