在预应力混凝土结构的计算中,徐变和干缩的影响是一个极重要的因素。由于混凝土构件因徐变和干缩而缩短,使所施加的预应力发生很大的损失。如在计算中对这种应力损失考虑不当,必致造成危险或浪费。在预应力混凝土结构研究成功以前,很多试验都是由于没有正确估计到混凝土徐变和干缩的巨大影响,以致日久所施加的预应力消失而告失败。我们现在虽然对混凝土徐变和干缩这种特性有了认识,各国的科学家们已经做过了无数次关于这方面的试验,但由于影响它的因素太多,至今还未能掌握其准确的规律;在实际计算中,还只能采用一些近似的规定。目前各国对这方面所做的规定还各不相同,其中德国预应力混凝土规范(DIN4227)的规定比较详细。它考虑了各种不同情况,因此 In the calculation of prestressed concrete structures, the influence of creep and shrinkage is a very important factor. Due to the creep and shrinkage of concrete components shortened, so that the applied prestress a great loss. If calculated in the loss of such improper stress, will cause danger or waste. Prior to the success of prestressed concrete structures, many tests failed due to the failure to properly predict the effects of creep and shrinkage on concrete. Although we now know the characteristics of concrete creep and shrinkage, scientists from all over the world have done countless experiments in this area, but because of the many factors that affect it, we have not yet mastered their accurate In the actual calculation, only some approximate rules can be adopted. At present, the regulations made by various countries in this area are still different. Among them, the provisions of German Prestressed Concrete Code (DIN4227) are more detailed. It considered a variety of different situations, therefore