论文部分内容阅读
2 钢筋混凝土管片为什么要加涂外防水层? 用钢筋混凝土管片拼装成环的地铁区间隧道,将永久埋卧于饱和含水的土层中。土层中的水常显示酸性和含有可溶性硫酸盐,对混凝土具有侵蚀作用。这种水通过毛细作用渗入混凝土结构内部,其渗入的速率取决于侵蚀性物质的浓度和混凝土本身的致密度(即毛细管径大小与数量)。混凝土遭受侵蚀的速度,主要取决于水中侵蚀剂的补给速率。因此评价腐蚀的危害性,必须研究土层水的渗流状况。
2 Reinforced concrete pipe pieces Why add a layer of waterproof coating? Use reinforced concrete pipe pieces assembled into a ring of subway tunnels, will be permanently buried in saturated water-bearing soil. Water in the soil often shows acidity and contains soluble sulphate, which has an aggressive effect on the concrete. This water penetrates into the interior of the concrete structure by capillary action and its rate of penetration depends on the concentration of aggressive material and the density of the concrete itself (ie, the size and amount of capillary diameter). The rate of erosion of concrete depends on the rate of supply of the etchant in the water. Therefore, the evaluation of the dangers of corrosion, we must study the seepage of soil water conditions.