部分预应力混凝土梁裂缝闭合性能的试验研究

２５根梁的试验结果表明，部分预应力混凝土梁具有良好的裂缝闭合性能，影响其裂缝闭合性能的主要因素有预应力度、裂面接触效应、混凝土徐变和加卸载的历史等。在分析试验结果的基础上，提出了确定裂缝闭合弯矩（或应力）的力学模型和计算公式。建议公式的物理概念明确，计算简便，计算值与试验值符合良好。

Experimental Research on Crack Closing of Partially Prestressed Concrete Beams

The test results of 25 specimens show that the cracks in partially prestressed concrete struc- tures are able to close after removing some loading , and that the major factors affecting crack clos- ing are degree of prestressing, crack surface contact effect , creep of concrete and loading history . Based on the test results, the calculation model and the method for predicting crack closing mo- ments ( or stresses) are presented. The formulas proposed in this paper are clear in physical con- cept and simple in calculation .Good agreement has been obtained between theoretical values and the test results .