超高韧性水泥基复合材料加固混凝土三点弯曲梁断裂过程的研究  

STUDY ON FRACTURE PROCESS OF CONCRETE THREE-POINT BENDING BEAMS RETROFITTED WITH UHTCC

作　　者：朱榆[1] 徐世烺[2] 

机构地区：[1]辽宁省建设科学研究院,沈阳110005 [2]浙江大学建筑工程学院,杭州310058

出　　处：《工程力学》2011年第3期69-77,共9页Engineering Mechanics

基　　金：国家自然科学基金重点项目(50438010)

摘　　要：该文利用超高韧性水泥基复合材料(UHTCC)所具备的较好的裂缝控制能力、较高的耗能能力、耐腐蚀性以及与混凝土之间良好的粘结性能,将其浇注在混凝土三点弯曲梁的受拉面,对加固后的混凝土三点弯曲梁的断裂过程进行了研究。首先由界面变形一致的假定,忽略了UHTCC未开裂区域的弹性变形,提出了UHTCC总裂缝宽度wu的确定方法,得到了σ-wu的简化模型,根据该简化模型便可以确定任意时刻UHTCC内的应力值;随后对UHTCC加固混凝土三点弯曲梁的裂缝扩展全过程进行了分析,并引入适用于UHTCC加固混凝土三点弯曲梁的起裂韧度K Iicni和失稳韧度K Iucn两个断裂参数,利用双K断裂准则对加固后的混凝土三点弯曲梁的裂缝扩展过程进行了描述,并通过试验对双K判定准则的适用性进行了验证。Ultra High Toughness Cementitious Composites（UHTCC） can be used as reinforcement material because of its good performances on crack control,energy consumption,corrosion resistance etc.The fracture process of concrete three-point bending beams retrofitted with UHTCC on tension face was studied.Based on the assumption that the interface deformation is consistent and by neglecting the elastic deformation of uncracked regions of UHTCC,a method for determining the total crack width wu of UHTCC is proposed and a simplified model of σ-wu is obtained subsequently.According to the simplified model,stress value of UHTCC can be determined.Through the analysis of whole process of crack propagation of concrete three-point bending notched beams retrofitted with UHTCC,the initial fracture toughness and the unstable toughness applicable for reinforced concrete were introduced.The double-K fracture criterion is used for describing the whole process of crack propagation of concrete three-point bending beams retrofitted with UHTCC,and then the applicability of the criterion is verified by tests.

关 键 词：超高韧性水泥基复合材料 加固 混凝土 三点弯曲梁 断裂 双K断裂准则 

分 类 号：TU599[建筑科学—建筑技术科学] TU375.1