1 、环境侵蚀：在雨雪导致的潮湿环境中，汽车尾气中的二氧化硫等，在水的作用下侵蚀结构混凝土表层，造成结构混凝土由表及里的疏松、粉化——这就是我们经常见到的浇筑多年的混凝土表面粉化、疏松等现象的原因。

1, environmental erosion: in damp environment caused by rain and snow, car tail gas of sulfur dioxide, and so on, in the concrete structure under the action of water erosion surface, cause its excellent structural concrete is loose, pulverization, this is what we often see pouring concrete table flour for many years, the phenomenon such as osteoporosis.

2 、碳化反应：二氧化碳、水和混凝土中的氢氧化钙结合生成溶于水的钙化合物并从混凝土中滤出，破坏了混凝土的碱性环境，降低其PH值，导致混凝土对钢筋的保护作用丧失，在潮气、氧气的作用下，导致钢筋锈蚀。

2, carbonation reaction: carbon dioxide, water and concrete in the calcium hydroxide in combination with water soluble calcium compounds and filter out from concrete and damage the alkaline environment of concrete, reduce its PH value, leading to loss of reinforced concrete protective effect, under the action of the moisture, oxygen, cause steel corrosion.

3 、氯离子侵蚀：化冰盐中的氯离子在潮湿的混凝土环境中，在钢筋锈蚀的过程中起到催化剂的作用：其本身并不被消耗，但却可以大大加速钢筋的锈蚀速度，所以对钢筋锈蚀的影响是持续且快速的。

3, chloride ion erosion: deicing salts of chloride ion in damp environment, concrete in the process of reinforcement corrosion have the effect of catalyst, its itself is not consumed, but can greatly accelerate the corrosion of steel bar speed, so the influence of reinforcement corrosion is the continuous and rapid.

4 、冻融破坏：水渗入混凝土内部，结冰膨胀，产生张力作用于混凝土，导致结构混凝土由表及里的破碎、脱落。

4, freeze-thaw damage: internal water seeping into the concrete, freezing expansion, tension in the concrete, lead to its excellent structural concrete is broken, fall off.

5、 钢筋锈蚀：环境侵蚀、氯离子侵蚀、冻融破坏在造成混凝土本身疏松、PH值降低的同时，还为钢筋提供了良好的锈蚀通道，丧失了对钢筋的保护功能，引发钢筋锈蚀。而钢筋锈蚀的直接危害就是导致了结构承载能力的下降，危及结构安全，同时锈蚀产物产生膨胀，导致钢筋保护层开裂、脱落，将钢筋暴露于大气中，加速其锈蚀。

5, reinforcement corrosion, erosion, chloride ion erosion environment, freeze-thaw damage in concrete itself loose, lower PH at the same time, also provides a good reinforcement corroded channel, lost the function of the protection of reinforcement, reinforcement corrosion. And reinforcement corrosion harm that directly lead to the decline of structural bearing capacity endanger security structure, meanwhile, the expansion of corrosion product, cause of reinforced protective layer cracking, fall off, the steel exposed to atmosphere, accelerate the corrosion.