自然碳化条件下混凝土结构的耐久性定量设计方法

Quantitative durability design method for concrete structures under natural carbonization conditions

为了克服传统耐久性设计方法主要基于工程经验和定性分析所存在的缺陷,研究建立了自然碳化条件下混凝土结构的耐久性定量设计方法。首先基于混凝土碳化分析的多场耦合数值模型,以50年服役寿命年限的碳化深度作为判别指标,确定了混凝土结构碳化环境作用的等级划分标准和量化表征体系;然后结合基于逐步回归分析的非线性拟合方法,分别利用二次、三次、四次多项式作为拟合函数,建立了自然环境条件下温度、相对湿度和CO2浓度对混凝土碳化深度的环境影响函数;最后以标准碳化环境下混凝土的碳化速率系数作为控制参数,建立了自然碳化条件下混凝土结构的耐久性定量设计方法。

In order to overcome the disadvantages of traditional durability design methods which are mainly based on engineering experience and qualitative analysis,a quantitative durability design method for concrete structures under natural carbonization condition was established.Based on the multi-field coupled numerical model of concrete carbonation analysis,the classification criteria and quantitative characterization of concrete carbonation environment were determined according to the carbonation depth of concrete with design service-life of 50 years.Then the quadratic,cubic and quadratic polynomials were adopted to fit the environmental impact function of temperatures,relative humidity and carbon dioxide concentration on the carbonation depth of the concrete under natural environmental conditions by using the non-linear regression analysis method.Then the quantitative durability design method for concrete structures under natural carbonation environmental conditions was proposed by adopting the carbonation rate coefficient of concrete under standard carbonation environment as the control parameter.