海洋工程混凝土耐久性研究

深入了解造成混凝土结构使用寿命缩短的原因,通过研究混凝土构件可靠度分析方法,对混凝土进行了配合比设计,试验结果表明掺人聚丙烯腈纤维比掺引气剂具有更好地提高混凝土冻融耐久性的作用.将混凝土表面氯离子浓度,保护层厚度和扩散系数作为随机变量,根据传统Fick第二定律建立了混凝土保护层中氯离子浓度的随机模型,基于体积稳定性设计的混凝土并掺人少量聚丙烯腈纤维后的混凝土显示了优良的抗氯离子渗透能力,从而提出了海洋环境下混凝土结构耐久性寿命评估的方法.

Study on the concrete durability of ocean engineering

In order to understand the causes of reduction of service life of existing concrete structures,based on the analytical method of reliability,an experiment was carried out to study the performance of mixture ratio design of concrete.The result showed that proper addition PAN fibers could better improve the freeze-thaw resistance of concrete than air-entraining agent.Treating three factors:chloride concentration at concrete surface,thickness of concrete cover and diffusion coefficient as random variable,a stochastic model of chloride concentration in concrete cover was bulit based on the Fick's second law.The concrete that was based on the design of volume stability and with proper addition PAN fibers showed good seepage resistance of chloride and then a method of evaluating durability and service life of the concrete in marine environment was proposed.