Abstract: This paper puts forward flexibility coefficient to evaluate the ameliorative effect of polymer cement concrete because many coefficient such as increasing percent of intensity of tension and the ratio of intensity of compression and tension can't appraise it wen．And this paper tests and computes flexibility coefficient of polymer cement concrete．Last this paper shows the flexibility coefficient can estimate the rupture property of polymer cement concrete by the relativity of flexibility coefficient and rupture property．

Key words: polymer cement concrete, flexibility coefficient, ameliorative effect, the relativity of flexibility coefficient and rupture property

摘要： 笔者通过论述抗折强度提高的百分比及压折比等参数不能很好的评价聚合物改性水泥砼的改性效果，提出 用柔度系数的概念来评价聚合物改性水泥砼的改性效果，并且测试计算了羧基丁苯改性水泥砼的柔度系数。最后 从柔度系数与断裂性能的相关性说明柔度系数能定性地评价聚合物改性水泥砼的断裂性能．

关键词: 改性水泥砼, 柔度系数, 改性效果, 与断裂性能的相关性