一、桥梁防水系统缺陷对桥梁损害的机理分析一般来说,水泥混凝土材料是耐水材料,在潮湿环境或水中能保持强度和稳定性,潮湿条件也是水泥混凝土材料早期强度形成和发展不可缺少的条件。但是长期处于潮湿条件下,尤其在干湿交替循环状态下,混凝土的耐久性问题是不容乐观的。很多桥梁墩台,在水位浮动的部位首先被破坏就是证明。京津塘高速公路龙风新河桥墩的被腐蚀就是典型的证明。空气中的水和雨水是一种成分很复杂的液体,再混入桥面的污物,常含有溶解气体、矿物质和有机质等,常见的有酸性物质、氧离子、氯离子、碳酸气等.这些物质超过一定限度时,就会腐蚀、侵害桥梁的混凝土和金属材料。水泥混凝土在塑性期或硬化初期会因为水分的蒸发造成塑性开裂。一般来说,桥面混凝土厚高小,和空气中的接触面积大,产生塑性开裂的机率也大。加强桥面混凝土施工的 First, the bridge waterproof system defects on the mechanism of damage to the bridge In general, cement concrete materials are water-resistant materials, in the humid environment or water to maintain strength and stability, wet conditions are also the early strength of cement concrete materials formation and development of indispensable conditions . However, long-term in wet conditions, especially in alternating wet and dry conditions, the durability of concrete is not optimistic. Many bridge piers, floating parts of the water level is the first to be destroyed is proof. Corrosion of Jingfengtang Longfeng New River Pier is typical proof. Air and rain water is a very complex composition of the liquid, and then mixed into the bridge of the dirt, often containing dissolved gases, minerals and organic matter, common acid, oxygen, chloride, carbon dioxide and so on. When these substances exceed certain limits, they corrode and invade the concrete and metal materials of bridges. Cement concrete in plastic or early hardening due to evaporation of water caused by plastic cracking. In general, the deck concrete thick and small, and the contact area in the air, the plastic cracking probability is also large. Strengthen the bridge deck concrete construction