钢筋混凝土结构锈胀开裂全过程仿真分析

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摘要：利用大型有限元软件 DIANA,详细分析了锈蚀导致混凝土保护层开裂的全过程.仿真分析
表明:混凝土保护层的锈胀开裂过程可分为内裂、扩展、外裂和内外裂缝贯通4个阶段;锈蚀产物膨
胀率一定时,混凝土保护层内侧裂缝的产生主要与混凝土抗拉强度相关,其他因素影响甚微；混凝
上休护层衣四方匯及员通王安与相对休护及有天，夏值，裂助越不容易发展：
是高混凝土抗拉强度，能有效延缓锈胀裂缝的产生和发展;在相同条件下,混凝土保护层非均匀锈
长开聚时的钢筋镑蚀率較均匀开裂时低；混凝土保护层剥落的特征王要与钢筋净问距和保护
层厚度的比值相关，当该值较大（>3）时，仅角区保护层发生局部剥落,否则保护层将整体剥落.
关键词：混凝土结构；钢筋；锈蚀；保护层；仿真分析
中图分类号：TU528.571
文献标志码:A
doi:10.3969/j.issn.1007-9629.2012.03.007
Simulation Analysis of Whole Cracking Process due to
Reinforcement Corrosion in Concrete Structures
XU Gang1…, XU Ke', WANG Qing’, WANG Yi-min°
(1.China Institute of Water Resources and Hydropower Research, Beijing 100038, China；
2.School of Civil Engineering & Architecture, China Three Gorges University；Yichang 443002，China
Abstract: By the large scale finite element software DIANA, the whole splitting process of concrete protec-
tive cover layer due to reinforcement corrosion was analyzed in detail. The simulation analysis shows that
the whole cracking process can be divided into four steps, that is, internal cracking , crack growth, exter-
nal cracking.and penetration cracking. At a certain level of the volumetric expansion ratio of corroded
products, the internal cracks initiation at internal side of the concrete protective layer around the steel bar
is mainly related to the tensile strength of concrete, and other factors have little effect on it. External
cracking as well as penetration cracking are related to the ratio of protective layer thickness to bar diame-
ter. The larger the ratio is, the more difficultly the crack propagation occurs. It is effective to improve the
tensile strength of concrete by delaying crack initiation and propagation；under the same conditions，the
critical corrosion ratio of reinforcing bar at cracking in non-uniform corrosion is lower than that in uniform
corros1on；the spalling patterns of concrete protectlve layer are malnly determ1ned by the rat1o of rebar
clear spacing to the protective layer thickness(L/C), when the L/C ratio is large enough (larger than 3）,
only the corner area spalls partly. Otherwise, the whole protective layer will spall.
Key words：concrete structure；steel bar；corrosion；cover；simulation analysis
混凝土中钢筋锈蚀产物的体积是被锈蚀部分的
2～7倍，因此，锈蚀产物会对周围的混凝土产生压