Effectiveness of silicate protecting layers of concrete structures

摘要

The protecting function of silicate protecting layers against water penetration is analyzed for fine grained concrete substrates with different water/cement ratio. Thermally cracked specimens of the studied substrates are prepared as well to simulate concrete corrosion and degradation. Basic material characteristics, namely bulk density, porosity, mechanical parameters and water and water vapour transport parameters, of studied fine grained concretes are analyzed first to obtain information about the behavior and properties of substrates. Then, water and water vapour transport parameters of fine grained concretes provided with the silicate protecting layers are determined and compared with those of corresponding substrates without any protection. The measured data show that the investigated silicate layers can protect effectively against moisture and corrosive solutions penetration only cracked concrete substrates. The properties of concrete substrates without cracks remain basically unaffected by the presence of the studied silicate protection, the main reason being the insufficient thickness of the protecting layer.