荷载与服役环境作用下混凝土耐久性的研究和进展

Research and Progress on Durability of Concrete under Combined Mechanical Load and Environment Actions

混凝土是基础设施建设不可或缺的工程材料,其耐久性是服役环境下混凝土结构寿命的重要保障。荷载作用引起混凝土材料微结构变化,荷载较大时,混凝土内的孔隙连通和微裂纹扩展影响到介质的渗透和传输。荷载和服役环境的叠加作用加速混凝土性能劣化,因此耦合作用下混凝土耐久性研究成为了国际关注的热点。综述了荷载与服役环境耦合作用下混凝土耐久性研究的探索和研究进展,总结了国内外在荷载-冻融循环、荷载-氯盐、荷载-碳化耦合作用下混凝土耐久性评价方法和表征参数等方面取得的重要突破,并介绍了荷载-冻融循环、荷载-氯盐耦合作用下混凝土寿命预测模型与方法的最新研究成果。最后,指出了现有荷载与典型服役环境作用下混凝土耐久性研究的局限性和后续的研究方向。

Concrete is an indispensable engineering material for infrastructure construction,and its durability is of great importance for the service life of concrete structures in service environments.External load causes the change of microstructure and pore structure of concrete,which affects the penetration and transportation of medium into the concrete matrix.When the load is large,micro cracks appear inside the concrete matrix and the connectivity increases gradually.The combined mechanical and environmental action leads to accelerated degradation of concrete performance.Therefore,durability of concrete under combined mechanical load and environmental actions has become a hot topic at home and abroad in recent years.The present paper reviews the exploration and research progress of concrete durability research under the combined mechanical load and environmental actions.The paper summarizes the important breakthroughs in the characterization parameters and evaluation of concrete durability under combined load and freeze-thaw cycles,load and chloride salt,load and carbonation,respectively.The latest research progress of the service life prediction models and methods for concrete under the combination of load and freeze-thaw cycles,load and chloride salts is introduced.In addition,the limitations of the existing research related to durability of concrete under combined mechanical load and environmental actions as well as the corresponding research prospective are outlined.