方桩混凝土中氯离子扩散数值模拟

摘要

Nowadays, the concrete structure is one of the main structure form of construction engineering, but due to its durability problem to countries around the world have brought huge economic losses. The comsol monitored the induction period for the first phase of the chloride ions corrosion. The main influence key factors for the length of induction period were analyzed, which were the chloride ions diffusion coefficient, the thickness of the protective layer and chloride ions concentration. Selecting the different water-cement ratio, the different thickness of the protective layer and choosing the actual chlorine ions concentration, their impact was analyzed. Result showed that the range of 70 ~80 mm was suggested as the protective layer thickness values, with the range value of 0. 3 ~0. 35 as the water cement ratio, which was the best combination for longer induction period. The method was applied to the engineering practice, predicted the induction period of China eastern harbour prestressed square pile in eight years.%钢筋混凝土结构是当今建筑工程最主要的工程结构形式之一，但由于其耐久性不足，给各国带来了巨大的经济损失。本文基于comsol对氯离子腐蚀段诱导期进行了监控，分析了影响矩形截面砼工程诱导期长短的主要因素：氯离子扩散系数、保护层厚度以及氯离子浓度。选取不同的水灰比、保护层厚度以及实际调查所得的氯离子浓度进行组合，分析出具体的影响。得出了70~80 mm与0.3~0.35分别为保护层厚度和水灰比的最佳取值，按此参数设计可以得到较长的诱导期。并将该法运用到工程实践，预测出华东地区某海港码头预应力方桩的诱导期为八年。