Development Of Permeable Concrete Silane Protective Paste

Because of its superior performance and low price, concrete is widely used inconstruction sector. At the same time concrete is vulnerable to corrosion by the outsidepollutants, therefore, protection of concrete become a hot research. Compared with otherprotective coatings, silane protective agent is more popular because of its permeability, goodwaterproof effect and long service life. In this paper, we briefly describe the protectiveprinciple and the development status of silicone protective agent and carry on a certainresearch in order to solve low capacity of domestic silane production, serious environmentalpollution, volatile and other issues. The main research contents are as follows:(1) Depending on the reaction characteristics, select and prepare appropriate catalyst.Results showed: Using homogeneous platinum ligand catalyst can promote the reactioneffectively. And this catalyst has good selectivity and low production cost. The reaction iseasy to implement industrialization. In the experiment, we have prepared five homogeneousplatinum ligand catalysts.(2) In order to solve the problem of pollution, we use hydrosilylation process to synthesissilane which raw materials are Olefin and TES, catalyst is homemade homogeneous platinumligand catalyst. Using the synthesis of Decyl triethoxy silane as an example, we haveconducted a study of the production process of hydrosilylation. Results showed: UsingPt-Divinyl tetramethyl disiloxane as catalyst, O2as co-catalyst, controlling n (Pt)/n (TES)=12.0×10-6, ratio of raw materials n (C10)/n (TES)=0.95, under the temperature of110℃react for4h, the yield of Decyl triethoxy silane can reach at97.15%and the production costis lowest.(3) Adopting the method of adding emulsifier, the experiment was prepared10kinds ofpermeable silane protective paste. And using the preparation of Decyl triethoxy silaneprotective paste as an example, we have conducted a study on the emulsification process.Results showed: Using complex emulsifier which was compound with Gransurf61andGransurf71as equal quality as emulsifier, the dosage of complex emulsifier at4.0%, Decyltriethoxy silane protective paste has uniform particle size distribution, lowest rate ofevaporation and best stability. According to the experimental results, paste can be stored for10d at50℃, while at the room temperature it can be stored over40days.(4) Contact angle, water absorption and penetration depth were used to characterized theperformance of paste. Results showed: Compared with the concrete without protection, thewaterproof properties of concrete after protection increased obviously. The contact angle isgreater than129.7°, the decrease of water absorption is greater than91.53%, and thepenetration depth is greater than3.0mm. The results also showed that composite type silaneprotective paste had best comprehensive protective properties, and increase the number ofcoating was in favor of improving the protective effect of concrete.