钢筋混凝土保护层锈胀裂缝宽度研究Ⅰ

Study-Ⅰ of corrosive crack width on reinforcement concrete cover

锈胀裂缝宽度是混凝土结构设计和耐久性评估的重要参数,基于裂缝开口部位的变形协调与混凝土的锈胀效应等特性,将裂缝宽度区分为几何位移与应力位移两部分,构建了裂缝宽度预测模型,且讨论了δ及η系数取值。为了探究不同因子对锈胀裂缝宽度的影响规律,分别进行了影响因子分析,结果表明:锈蚀产物膨胀率对锈胀裂缝的影响非常大;钢筋直径及保护层厚度对裂缝扩展宽度的影响非常小;而混凝土弹性模量的影响可近似取为零。

Crack width is a most significant parameter for the structural design and durability assessment of reinforced concrete structures. Based on deformation coordination of cracks, open position and corrosive effect of concrete, and so on, crack width is divided into two parts of the geometric displacement and the stress displacement. A predicting model for crack width is built. Simultaneously the proposal value and coefficient are discussed. The analysis of the impact factors is carried out separately to explore the effect of different factors on corrosive crack width. The results show that the expansion rate of corrosion product has great impact on corrosive cracks, but bar diameter and thickness of concrete cover have little impact on the crack width, and Young＇s modulus of the concrete has almost no impact on that.