Abstract: Since there is cement ooncrete，the crack problem have had been obsessing people．The existence of crack not only affects the appearance the building，but also influences the rigidity ofthe construction number and the capability of the whole structure，pursuantly it affeets the normlal usage of the building．So how to resolve this problem becomes the focus of people's attention gradually．This text has analyzed the concrete crack type and the cause of the crack in brief，and given an experiment on the cement sand syrup，the result has proved that the effection of the polypropylene fiber is remarkable．

Key words: the concrete crack, plain cement sand syrup, polypropylene fiber cement sand syrup, resist the plastic and corky crack

摘要： 自从有水泥砼以来，裂缝问题就一直困扰着人们．裂缝的存在不仅影响建筑物的外观，而且影响构件的刚度 和结构的整体性，从而影响建筑物的正常使用．如何解决这一问。题渐渐成为人们关注的焦点．本文简单分析了砼裂 缝类型及成因，并通过水泥砂浆抗塑性干缩开裂试验说明聚丙烯纤维在水泥基材料抗塑性干缩开裂能力方面的作 用．

关键词: 砼裂缝, 素水泥砂浆, 聚丙烯纤维水泥砂浆, 抗塑性干缩开裂