混凝土对钢筋初锈阶段锈蚀产物分布的影响  

Influence of concrete on the distribution of corrosion products at the initial stage of steel corrosion

作　　者：王海宇 赵羽习[1] WANG Haiyu;ZHAO Yuxi(College of Civil Engineering And Architecture,Zhejiang University,Hangzhou 310000,China)

机构地区：[1]浙江大学建筑工程学院,浙江杭州310000

出　　处：《混凝土》2024年第8期7-13,共7页Concrete

基　　金：国家自然科学基金(51978604)。

摘　　要：为了研究不同水灰比及掺合料在钢筋锈蚀初期对锈蚀产物分布的影响,通过扫描电镜观测得到不同混凝土试件内不同截面的钢筋锈蚀率及锈蚀产物在钢筋/混凝土界面附近的分布情况,并通过压汞试验得到各个试样的孔隙率。试验结果表明:相同锈蚀条件下,钢筋锈蚀率随着混凝土孔隙率的增大而呈现加速增长的趋势。钢筋锈蚀初期的试验观测还发现:锈蚀产物会在钢筋/混凝土界面逐渐积累为锈层,也有部分锈蚀产物会填充到附近砂浆的孔隙中,据此给出了锈蚀产物在混凝土内的传输行为;锈蚀产物在钢筋表面形成的锈层分布随机,难以采用模型进行描述,只有当钢筋锈蚀发展到一定程度后,才可能用以往提出的钢筋截面非均匀模型进行合理表达。In order to study the influence of different water cement ratios and admixtures on the distribution of corrosion products at the initial stage of reinforcement corrosion,the corrosion ratio of reinforcement in different sections of different concrete specimens and the distribution of corrosion products near the reinforcement/concrete interface were observed by scanning electron microscope,and the porosity of each specimen was obtained by mercury intrusion test.The results show that under the same corrosion condition,the corrosion ratio of reinforcement increases with the increase of concrete porosity.The experimental observation at the initial stage of rebar corrosion also found that the corrosion products would gradually accumulate as a corrosion layer at the rebar/concrete interface,and some of the corrosion products would fill the pores of nearby mortar,based on which the transmission behavior of corrosion products in concrete was given;The corrosion layer on the steel surface is distributed randomly,which is difficult to describe by existing models.Only when the steel corrosion develops to a certain extent,it can be reasonably expressed by the previously proposed non-uniform distribution models.

关 键 词：水灰比 掺合料 钢筋锈蚀 锈蚀产物分布 

分 类 号：TU528.01[建筑科学—建筑技术科学]