水化硅酸钙溶解侵蚀钢筋混凝土渗透扩散数值模拟

Numerical Simulation of Osmotic Diffusion of Reinforced Concrete by Dissolution Erosion of Hydrated Calcium Silicate

通过考虑水化硅酸钙的溶解侵蚀作用,结合流体与化学动力学相关理论,建立钢筋混凝土管道渗透扩散-侵蚀耦合模型,并通过工程实例,分析模型的变化规律。研究表明:水泥基的体积分数、管道压强、对水体渗透扩散距离成线性正相关,水灰比成非线性正相关,而水化程度则成线性负相关;在相同的条件下,级配较好的钢筋混凝土渗透范围更小,压强变化对其渗透距离的影响也更小。通过正交分析得到不同因素的影响程度为:管道压强>水灰比>水泥基的体积分数>渗透时间>水化程度。通过对该工程设计参数验证,认为该工程设计参数合理。研究成果可为预测水体在钢筋混凝土管道中的渗透扩散范围提供理论依据。

By considering the dissolution erosion effect of hydrated calcium silicate and combining the relevant theory of fluid and chemical kinetics,an osmotic diffusion-erosion coupling model for reinforced concrete pipe was established,and then the change law of the model was analyzed according to engineering examples.The study shows that,the volume fraction of cement base and the pipe pressure are of linear positive correlation to the osmotic diffusion distance of waters,the water-cement ratio of nonlinear positive correlation,and the hydration degree of linear negative correlation.Under the same conditions,the permeation range is smaller in case of reinforced concrete with better grading,and the impact of pressure change on the permeation distance is also smaller.By means of orthogonal analysis,the degree of influence of different factors is obtained as follows:pipe pressure>water-cement ratio>volume fraction of cement base>penetration time>degree of hydration.Through the veritification of the engineering design parameters,it is considered that the engineering design parameters are reasonable.The research results can provide a theoretical basis for predicting the osmotic diffusion range of waters in reinforced concrete pipe.