摘要
近海及海洋工程结构的混凝土在服役过程中不仅会经受环境作用(如氯盐侵蚀),还会承受包括风、车辆、波浪荷载甚至地震作用等。荷载作用不仅会改变混凝土中微/细观结构形式,甚至产生新的裂纹,改变氯离子的渗透扩散途径,从而影响混凝土的渗透扩散特性。从低荷载水平和高荷载水平两个方面,分别综述了荷载对混凝土中氯离子渗透及扩散性能影响的试验研究、理论分析及数值分析角度的研究进展,发现已有研究工作特点为:试验研究多,理论研究少;饱和混凝土研究多,非饱和混凝土研究少;宏观模型研究多,微/细观非均质模型研究少。建议今后进行复杂环境、复杂应力状态下的试验研究,建立高/低水平荷载对氯离子扩散行为影响的统一理论及数值模型,实现荷载-环境耦合作用下的多场多尺度分析。
In coastal areas, concrete structures are not only subjected to environmental attacks （e. g. the penetration and diffusion of chloride ions） but also the mechanical loadings including wind loads, vehicle loads, wave loads and even seismic loads. The external mechanical stresses may change the micro-/meso-structure of concrete, and even cause new micro-cracks to be generated. This leads to the change of the penetration and diffusion boundary conditions of chloride ions, and finally the change of the permeability and diffusivity of chloride ions. From the viewpoints of lower and higher mechanical stress levels, the available experimental, theoretical and numerical efforts to study the effects of external loadings on chloride ions penetration and diffusion into concrete were introduced. One can note that the available efforts mainly focus on experimental tests rather than theoretical analysis. The concrete studied is mostly saturated instead of unsaturated. Moreover, the analysis is conducted based on the macro-scale model for the most part, without considering the meso-scale heterogeneity of concrete. Finally, it is suggested that experiments on chloride penetration and diffusion into concrete in the complex environment and complex stress state should be conducted. A model that unifies the influences of lower stress level and higher stress level needs to be established. The multi-field and multi-scale analysis of chloride diffusion in concrete under the coupling effects of mechanics and environment should be carried out in future.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2016年第1期107-125,共19页
Journal of Building Structures
基金
国家重点基础研究发展计划(973计划)项目(2011CB013600)
国家自然科学基金创新研究群体项目(51421005)
关键词
混凝土
荷载
裂纹
氯离子
渗透
扩散
concrete
mechanical loading
crack
chloride ions
permeability
diffusivity
