混凝土内钢筋锈蚀层发展和锈蚀量分布模型研究

从研究钢筋锈蚀物膨胀对钢筋/混凝土界面区构造的影响着手,通过对锈蚀层形成、发展及其细观构造的研究,揭示混凝土内钢筋锈蚀量分布规律;在钢筋锈胀开裂前,钢筋锈蚀量基本分布在面向混凝土保护层一侧的钢筋半圆周上,离混凝土保护层最近处锈蚀量最大,离保护层表面距离越远,锈蚀量越小;其锈蚀量在其半圆周上呈半椭圆形分布。钢筋锈胀开裂初期,钢筋锈蚀逐渐向背向混凝土保护层一侧发展,在背向保护层一侧的钢筋锈蚀量分布被假定为均匀分布,和面向混凝土保护层一侧的最小锈蚀量衔接。

Propagation and model of distribution for corrosion of steel bars in concrete

Predicting concrete cracking due to corrosion of steel bars is an important issue for the durability of reinforced concrete structures. At present, an assumption of uniform corrosion distribution along the perimeter of the steel bar has been adopted for analyzing the effect of corrosion expansion. This is due to the lack of the research on corrosion distribution of steel bars in concrete. In this study, the propagation of the corrosion layer and its microstructure is revealed. Before corrosion-induced cracking occurs, the corrosion of steel bars is mainly on the side facing the concrete cover, maximum corrosion occurs at the nearest point from the concrete cover, and the corrosion level is lower for the part of bar surface away from the concrete cover. Corrosion mainly occurs at the half circumferential perimeter of the steel bar facing the concrete cover, with the shape being a half ellipse. After corrosion cracking, the corrosion propagates from the side facing the concrete cover deeper into the concrete cover. Uniform corrosion distribution is observed on the bar surface away from the concrete cover.