Strength Enhancement of Geopolymer-Based Concretes by Mixed Alkaline Activators
As a relatively new material, geopolymer concrete offers benefits as a construction material for sustainable development. It utilizes waste materials such as recycled concrete sludge, fly ash,etc. To reduce CO2 emission, geopolymer concrete is expected to replace the traditional Portland cement based concrete. It’s reported that geopolymer based concrete releases only 1/6 CO2 compared to those of based Ordinary Portland Cement (OPC). In this study, to obtain a new type of construction material with lower CO2 emission and energy consumption, fly ash, waste concrete sludge and metakaolin were used as the main components. Solution of NaOH/KOH and water glass were applied as alkaline activator. The amount of water glass and the ratio of alkaline/water glass were varied to reach an optimal value. Also, silica fume was added as a bonding matrix to enhance the strength, and the specimens were cured in air and oven, then their mechanical properties such as compressive strength and bending strength were measured and their microstructures were investigated.
Hyungsun Kim, JianFeng Yang, Tohru Sekino, Masakazu Anpo and Soo Wohn Lee
Z. X. Yang et al., "Strength Enhancement of Geopolymer-Based Concretes by Mixed Alkaline Activators", Materials Science Forum, Vol. 658, pp. 292-295, 2010