The Development Of Osmotic Organosilicon Protective Coatings On Concrete Surface

The penetrability is one of the main influencing factors of concrete durability. After compared, the waterproofing coatings are one of the most convenient and effective ways to reduce the penetrability of concrete. Organic silicon penetrating agent can permeate into concrete from surface, forming a breathable and waterproof coating. Silicone penetrant coating has no bubbling and rupture problems with comparison to other coatings.The classification, research and application of silicone penetrant were introduced. At present, the low-molecular-weight organic silicon monomers were often used as penetrating agent which had high volatilizing ratio and serious loss. According to this problem, some research work was done as follows.1. Put forward the idea of using low molecular polymer of silane or siloxane to replace silane or siloxane monomer. Based on the mechanism of radical polymerization and hydrolysis-condensation, the appropriate raw material was selected, orthogonal experiments was designed, the influence law of factors were studied, and a reasonable formula and process were gotten. The volatilizing ratios of YJG-ZYJ and YJG-SJ are 18.68% and 29.23% respectively, and they are lower than those of other products in the market obviously.2. The monomer, YJG-ZYJ and YJG-SJ were choosed to detect their infrared spectral. By tcomparing spectra, it is found that double bond of YJG-ZYJ gotten from Radical Polymerization has been opened and Si-O-Si bond of YJG-SJ gotten from hydrolysis polycondensation has formed. After gel permeation chromatography detection, the number average molecular weight of YJG-ZYJ and YJG-SJ was obtained.3. In accordance with the relevant norms, water absorption, content of chloride ion and penetration depth on concrete has been researched. The absorption ratio, effection of chloride ion attenuation, and penetration depth of diluted YJG-ZYJ is 5.56%, 100%, and 4.5mm, respectively. And that of YJG-SJ is 5.03%, 100%, and 3.8mm, respectively. The test results met the requirements of standards.The results show that the obtained silicone osmotic agent not only solved the problem of high evaporation ratio, but also maintained excellent waterproof performance.