海洋潮汐区混凝土表面氯离子浓度的时变规律及多因素模型

Multi-factor Model and Time-varying Law for Surface Chloride Concentration of Concrete in Marine Tidal Zone

针对现有模型无法合理考虑胶凝材料种类和暴露时间对潮汐区混凝土海洋环境作用的耦合影响,基于631组海洋潮汐区野外暴露试验数据,本研究建立了海洋潮汐区混凝土表面氯离子浓度的多因素时变模型。首先分析了暴露时间和材料因素对表面氯离子浓度的影响规律,然后通过引入时间系数和稳定系数修正表面氯离子浓度的多因素模型,进而根据两阶段非线性回归分析确定待定模型参数,从而建立了一种能够综合考虑胶凝材料种类和暴露时间耦合影响的潮汐区混凝土表面氯离子浓度多因素时变模型,最后通过与潮汐区野外试验数据和现有计算模型的对比分析,验证表明该模型能够综合考虑水胶比、胶凝材料种类和暴露时间等因素的耦合影响,具有广泛适用性。

In order to overcome the limitation that existing models cannot take into account the coupling effect of binder type and exposure time on the environmental action of concrete in tidal zone,a multi-factor time-varying model for surface chloride concentration of concrete was developed based on a total of 631 sets of field data selected from tidal zone.The influences of exposure time and material factors on surface chloride concentration of concrete in tidal zone was analyzed first.Then the multi-factor time-varying law of surface chloride concentration was corrected by introducing the time factor and the stability coefficient.Moreover,the unknown coefficients of multi-factor time-varying model were determined by means of the two-stage regression analysis method,while a multi-factor time-varying model for surface chloride concentration of concrete which takes into account the coupling effect of binder type and exposure time was developed.Finally,the proposed model was validated by comparing with the exis-ting models and field data,which indicates that the proposed model is of high applicability and it can comprehensively takes into account the coupling effect of water-to-binder ratio,type of binder and exposure time.