Cracking of concrete induced by rebar corrosion is a main cause for deterioration of reinforced concrete structures especially for those exposed to chloride environment. In all of the parameters influencing the service life of concrete structures, water-to-cement ratio is a very important one for it determines the resistance of concrete against chloride aggression and corrosion-induced damage. In this paper, the parameters in corrosion process influenced by water-to-cement ratio of concrete (w/c) are screened all-round which include concrete tensile strength f_t, elastic modulus E_c, porous zone thickness δ₀, corrosion current density i_corr, critical chloride content C_cr, and chloride diffusion coefficient D_cl. The influences of w/c on the chloride penetration stage and the corrosion damage stage are studied. The first stage is expressed by Fick's second law, and the second stage is calculated using a commonly used analytical model, i.e. the thick-walled cylinder model. It is found that with the increase of w/c, the change of some parameters (f_t↑, C_cr↑, D_cl↓, i_corr↓) will induce increase of the service life, while the change of the others (E_c↑, δ₀↓) will induce decrease of the service life. The diffusion stage and damage stage both shorten with the increase of w/c, and thus the total service life decreases with the increase of w/c. These results show that the increase of w/c presents a negative effect on the service life of concrete structures in total. In addition, with the increase of w/c, the service life for various concrete cover thicknesses and rebar diameters decrease in a similar tendency. For probability analyses, it is found that the probability density curves under different w/c are almost symmetric but show a little left-skewed, and the total service life for various w/c fluctuates about 0.6 to 1.0 year.

中文翻译：

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氯化物环境下水灰比对钢筋混凝土结构使用寿命的影响

钢筋腐蚀引起的混凝土开裂是钢筋混凝土结构劣化的主要原因，尤其是暴露于氯化物环境中的混凝土结构。在影响混凝土结构使用寿命的所有参数中，水灰比是一个非常重要的参数，它决定了混凝土对氯化物侵蚀和腐蚀损伤的抵抗力。本文全面筛选了混凝土水灰比（w / c）影响腐蚀过程的参数，包括混凝土抗拉强度f _t、弹性模量E _c、多孔区厚度δ ₀、腐蚀电流密度i _corr、临界氯化物含量C _cr和氯化物扩散系数D _cl。研究了w / c对氯化物渗透阶段和腐蚀破坏阶段的影响。第一阶段用菲克第二定律表示，第二阶段使用常用的解析模型计算，即厚壁圆柱模型。发现随着w / c的增加，一些参数（f _t ↑, C _cr ↑, D _cl ↓, i _corr↓) 会导致使用寿命的增加，而其他( E _c ↑, δ ₀ ↓) 的变化会导致使用寿命的减少。扩散阶段和破坏阶段都随着w / c的增加而缩短，因此总使用寿命随着w / c的增加而降低。这些结果表明，w / c的增加总体上对混凝土结构的使用寿命产生负面影响。另外，随着w / c的增加，各种混凝土保护层厚度和钢筋直径的使用寿命以类似的趋势下降。对于概率分析，发现不同w / c下的概率密度曲线几乎对称，但略有左偏，不同w / c的总使用寿命在0.6至1.0年左右波动。