为了准确预测混凝土碳化深度的时变演化规律,基于周期性边界条件,本文提出了改进的水泥水化数值分析模型。引入中心水泥颗粒的未水化水泥层、水化产物层和空气层的受干扰程度3个参数量化表征了水化过程中水泥颗粒之间的干扰效应,考虑水泥矿物组分、水灰比、粒径分布对水泥水化进程的影响,分析了水泥水化度、孔隙率、水化产物随龄期的发展变化规律。结合Papadakis的混凝土碳化深度预测模型,提出了基于水泥水化的混凝土碳化深度预测方法。采用标准碳化试验方法对本文提出的模型进行了验证,试验研究表明模型预测结果与试验结果吻合良好,本文提出的混凝土碳化深度预测模型对研究混凝土耐久性具有重要意义。
Based on the periodic boundary conditions, tablished in this paper to precisely predict the time an improved numerical cement hydration model is es- varying development of carbonation depth in concrete. Three parameters, including the interfered degrees of unhydrated cement layer, hydration product lay- er and air layer of central cement grains during the hydration process, are introduced to quantitatively rep- resent the interference effect between cement particles. Considering the influence of cement mineral composi- tions, water to cement ratio (w/c), particle size distribution on cement hydration process, the development of hydration degree, porosity and hydration products with age are analyzed. Based on the prediction model of carbonation depth in concrete established by Papadakis, a method for predicting the carbonation depth in concrete is proposed in considering cement hydration. The standard carbonation test method was used to verify the model proposed in this research. It can be seen from the experimental research that the numeri- cal simulation results agree well with the experiment. And the prediction model of carbonation depth estab- lished in this research is of great importance to the durability investigation of concrete.