Permeable silane impregnated coating is a kind of waterproof coating. It was developed in 1990s in China and was widely used in the concrete anti-corrosion construction of port and wharf. With the continuous development and application of silane, the application scope of silane has also evolved from the original port and wharf to the port engineering, traffic engineering, industrial facilities and civil buildings corrosion protection. Next, we will discuss and share some issues related to silane.


First of all, why can silane play the role of concrete anti-corrosion?


Concrete will be eroded by water and chloride ion in the open environment, which will affect the durability of the structure itself. In fact, water will cause a lot of structural diseases of concrete, which is the carrier of many diseases. Therefore, waterproof measures on the surface will play a great role in the anti-corrosion of concrete. Silane is a kind of penetrating impregnant with excellent performance. It has a small molecular structure. The capillary wall of deep penetrating concrete reacts with hydrated cement to form a polysiloxane interpenetrating network structure. Through a firm chemical bonding reaction, the micro structure of concrete surface is given a long-term hydrophobicity, and the function of breath and air permeability is maintained, thus greatly reducing the invasion of water and harmful chloride ions Ensure the concrete structure is free from corrosion.

Second, what is the difference between silane and other waterproof coatings?

Permeable organic silane surface protective coating is a kind of waterproof coating. The difference between permeable organic silane surface protective coating and other waterproof coatings is that the former uses the permeability of concrete to penetrate into a certain depth of concrete surface for immersion protection, while the latter completely blocks the pores or seals the capillary pores on the surface. Therefore, the silicone impregnation protection can not only significantly reduce the water absorption of the concrete pores, reduce chloride ion erosion, prevent freeze-thaw damage, steel corrosion and mold growth, but also ensure long-term durability (alkali resistance, UV resistance).

Thirdly, how can the anti-corrosion effect of silane be guaranteed to the greatest extent during construction?

The following conditions shall be met: concrete age ≥ 28 days; concrete grade is c30-c45; concrete surface is dry and clean, free of obvious dirt, dust and pockmarks; there is basically no rain, strong wind and other bad weather within 7 days of construction; silane consumption shall be measured according to the instructions; concrete surface temperature is between 5-40 ℃. If the above conditions are basically met, spray silane (liquid or paste) for 7 days, and the effect is obvious.


Fourth, the more silane is used, the better?


The amount of silane should be within the appropriate range. Excessive amount of silane will lead to the following results: first, the appearance of the concrete structure will change in color, the surface will turn black, there will be stains, and the color can only be restored in the later stage; second, the effect of hydrophobicity will become worse, and the lotus leaf effect after 7 days of curing will be less obvious than that of the normal amount of concrete.