Durability related environmental zonation and design methodology for marine RC structures

海洋钢筋混凝土结构耐久性环境区划与设计方法（英文）

A reliability-based quantitative durability design methodology is presented for reinforced concrete(RC)structures in the marine environment on the basis of natural exposure data derived from four berths(1.5,1.5,4 and 15 years)of a concrete port.More than 200 chloride profiles are obtained and analyzed.The relationship between nominal surface chloride ion concentration and altitude is discussed.Subsequently,the formula of the apparent chloride diffusion coefficient is proposed with consideration of the surrounding temperature,sodium chloride solution concentration,age factor and altitude.Then,the reliability-based method to predict the durability of RC structures is developed according to Fick s second law.Relationships between the predicted penetration depth of the chloride ion,the ratio of the wetting time per-period and the corresponding altitude are discussed.Subsequently,the environmental zonation methodology is established for concrete structures under a marine chloride environment by considering the ratio of the wetting time per-period of concrete as the zoning index.Finally,the corres-ponding durability design method for each zone level is established,which contains the durability design regulations of the specimen,and correction coefficients for different water/binder ratios,ages,temperatures and chloride ion concentrations.

针对海洋环境中的钢筋混凝土结构,基于某混凝土港口4个泊位的自然暴露检测数据(暴露时间分别为1.5,1.5,4,15年),提出了一个基于可靠性的混凝土结构耐久性定量化设计方法.基于检测得到的200多条混凝土中氯离子含量随侵蚀深度的分布曲线,对表面氯离子浓度与高程的关系进行了讨论,进一步提出了考虑环境温度、氯离子浓度、龄期系数和高程等因素的表观氯离子扩散系数的计算公式.然后,依据Fick第二定律,建立了基于可靠度的钢筋混凝土结构耐久性概率预测方法.讨论了混凝土氯离子侵蚀深度预测值、浸润时间比和高程的关系,建立了以海水浸润时间比为指标的海洋环境区划体系.最后,建立针对环境区划体系的分区设计方法,包括了标准试件的分区设计规定和不同水胶比、设计年限、温度、氯离子含量修正系数的分区设计规定体系.