The reaction between rice husk ash and Ca(OH)2 solution and the nature of its product

摘要: Abstract In this study it was confirmed that, at temperatures around 40°C and in the presence of water, amorphous silica contained rice husk ash (RHA) can react with Ca(OH)2 to form one kind C-S-H gel (Ca1.5SiO3.5· xH2O). The looks like flocs morphology, a porous structure large specific surface. average particle diameter reaction product, ranging from 4.8 7.9 μm, varies slightly condition under which occurs. When product is heated, gradually loses water that exists it, but maintains an up 750°C. Above 780°C begins transform crystalline CaSiO3. One main reasons for improvement concrete properties upon addition RHA possibly may be attributed formation more less portlandite due occurring between Ca2+, OH− ions, or hydrating cement.