摘   要：对锈蚀开裂的混凝土构件进行受损程度的评估时，裂缝宽度往往是重要指标之一。为使对锈蚀构件的评估定量化，获得混凝土保护层裂缝宽度和钢筋锈蚀程度的关系便成为首要的问题，用膨胀螺栓对混凝土试件的预留孔持续施加径向位移（变形），以此模拟钢筋锈蚀产物的膨胀，对94个混凝土试件进行了扩孔试验，直到试件出现裂缝并且裂缝继续扩展，这被称为机械扩孔法。试验过程中，用游标卡尺测定径向膨胀，以及用专用裂缝宽度笔测得相应的裂缝宽度。对试验数据进行分析和曲线拟合，得到包括混凝土抗拉强度、保护层厚度、钢筋直径等影响因素的裂缝扩展模型，结果与文献观测值基本吻合。

Abstract: In evaluation of corrosion degree of reinforced concrete structure, and in order to make this evaluation to be in quantification, it becomes a very important thing for getting the relationship between the cracks width of cover concrete and the corrosion degree of reinforcement. Therefore, the tests to be called mechanically expanded hole are carried out, i.e. a pre-left hole in concrete speciment is continuously enlarge by a expanded bolt to the direction of radiation untill the cracking is happened and the cracks are extended without cease, by which the expansion of products of corroded steel is simulated. Both radius expansion rate of the pre-left holes and cracks width of cover concrete are simultaneously recorded during the test process, and based on the analysing of data taken from the tests a model of cracks extention is built up, including the factors of concrete tensile strength, concrete cover width and diameter of reiforcement.