冻融环境下混凝土力学性能退化模型  

Mechanical Property Deterioration Model for Concrete in Environment with Freezing-thawing

作　　者：祝金鹏[1] 李术才[1] 刘宪波 刘敏 

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061 [2]山东省公路桥梁建设有限公司,山东济南250014

出　　处：《建筑科学与工程学报》2009年第1期62-67,共6页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(50574053);山东省博士后创新项目(200703072)

摘　　要：基于混凝土冻融试验和混凝土细观力学对混凝土冻融后的力学性能变化进行了研究,建立了混凝土随冻融循环次数变化的强度折减模型和弹性模量折减模型。在混凝土冻融试验方面,采用快速冻融方法对混凝土试件和根据混凝土配合比制成的砂浆试件进行了100、200、300次的冻融循环,利用大型混凝土静、动三轴试验系统检测了冻融循环对海水中混凝土抗压强度、弹性模量及应力-应变关系的影响;在混凝土细观力学方面,对混凝土试件进行了数值模拟,为考虑各组成相的非均匀性,各组成相的材料性质按照Weibull分布来赋值,同时为反映冻融对混凝土的影响,砂浆的强度和弹性模量均以砂浆冻融试验所得结果为准。结果表明:该方法为进一步开展混凝土结构在冻融作用下的劣化机理与计算模型的研究提供了依据。Based on the freezing-thawing test and micro-mechanics of concrete, the mechanical properties of concrete after freezing thawing were studied, and the strength reduction model and elastic modulus reduction model were built with the changes of freezing-thawing cycles of concrete. In aspects of freezing-thawing test, the compressive tests of concrete specimens and mortar specimens which were made according to the ratio of concrete suffering 100, 200 and 300 cycles of freezing-thawing were completed. Using the large static-dynamic triaxial test system for concrete, the influences of cycles of freezing-thawing on the compressive strength of concrete, elastic moduli and stress strain relationships were tested. In aspects of micro-mechanics, examination of the concrete specimen was numerically simulated. To consider the non-uniformity of the various components, the nature of the material of the various components was assigned in accordance with the Weibull distribution. In order to reflect the impact of freezing-thawing to concrete, the strength and elastic modulus of mortar specimens were both assigned according to the results of mortar freezing thawing test. The results show that this method can offer references for further research on deterioration mechanism and calculation model of reinforced concrete structures in actions of freezing-thawing cycles.

关 键 词：混凝土 强度折减模型 冻融循环 细观数值模拟 力学性能 

分 类 号：TU375[建筑科学—结构工程]