荷载作用下混凝土中氯离子传输的数值分析方法  

Numerical analysis method for transport of chloride ions in concrete under load effect

作　　者：金立兵[1] 王珍 梁新亚 段海静 JIN Libing;WANG Zhen;LIANG Xinya;DUAN Haijing(School of Civil Engineering and Architecture,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学土木建筑学院,河南郑州450001

出　　处：《混凝土》2020年第9期60-64,共5页Concrete

基　　金：国家自然科学基金项目(51509084,51508162)。

摘　　要：为了得到荷载作用下氯离子在混凝土中传输的数值模拟方法,通过对海工混凝土长期暴露试验进行数值分析,验证了多因素作用下氯离子传输模型和数值分析方法的有效性,该模型综合考虑了水灰比、时间、结合效应、温度、湿度、混凝土劣化的影响;在此基础上,将荷载对混凝土中氯离子传输的影响等效为荷载引起的混凝土孔隙率变化,实现荷载与氯离子传输之间的耦合作用。对弯曲荷载作用下混凝土中氯离子侵蚀试验进行数值分析,数值分析结果与试验结果吻合较好。分析了不同应力状态及应力水平、混凝土孔隙率及弹性模量对氯离子传输的影响。结果表明:拉应力加快了氯离子在混凝土内传输,在压应力作用下,氯离子在混凝土内传输速率降低;随着混凝土孔隙率增大,氯离子扩散加快;混凝土弹性模量改变对氯离子扩散几乎没有影响。本数值方法可为混凝土耐久性设计以及寿命预测提供参考。In order to get the numerical simulation method for the transport of chloride ions in concrete under load effect,the validity of the chloride ion transport model and numerical analysis method under multi-factor effects were verified through numerical analysis on long-term exposure test of marine concrete,and the effects of the water-cement ratio,time,combination,temperature,humidity and concrete deterioration are comprehensively considered.On this basis,the influenced of the transport of chloride ions in concrete under load effect are equivalent to the changes in the porosity of concrete under load effect for coupling between load and chloride ion transport.Numerical analysis is carried out for the test on chloride ion erosion in concrete under the bending load,and numerical analysis results agreed well with experiment results.The effects of different stress states and levels,concrete porosity and elastic modulus on the transport of chloride ions are analyzed.The results showed that transport of chloride ions in concrete was accelerated under tensile stress.Under compressive stress,the transport speed of chloride ions in concrete was reduced;with the increase of the concrete porosity,the diffusion of chloride ions speeded up;the changes in elastic modulus of concrete had little influence on the diffusion of chloride ions.This numerical method can provide a reference for durability design and life prediction of concrete.

关 键 词：混凝土 氯离子 侵蚀 传输模型 应力 数值模拟 

分 类 号：TU528.01[建筑科学—建筑技术科学]