Chemical and freeze–thaw resistance of fly ash-based inorganic mortars

• Published in: Fuel (Guildford) Vol. 111; pp. 740 - 745
• Main Authors: Sun, Peijiang, Wu, Hwai-Chung
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-09-2013; Elsevier
• Subjects: Alkali activation; Applied sciences; Cement; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fly ash; Fuels; Geopolymer; Inorganic polymer; Fly ash; Geopolymer; Alkali activation; Inorganic polymer; Cement; Costs; Chemical resistance; Activation; Portland cement; Pollutant emission; Sulfuric acid; Energy conservation; Sodium sulfate; Cost analysis; Freeze; Strength
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2013.04.070

•Investigates freeze–thaw durability of fly ash based alkali activated mortars which were cured under ambient conditions.•Investigates sulfate and sulfuric acid resistance of fly ash based mortars which were cured under ambient conditions.•Compares with Portland cement mortars.•Discusses the importance of composition tailoring.
Inorganic cements have many advantages over Portland cement including energy efficiency, reduced greenhouse gas emissions, rapid strength gain, and improved temperature resistance. Alkali activated cements made from waste materials such as fly ash, are particularly advantageous because of their environmental sustainability and low cost. However, their long term durability is yet to be confirmed. In this study, the chemical and freeze/thaw resistance of fly ash based inorganic mortars was investigated. Specimens of various compositions were tested to determine their chemical and freeze–thaw resistance. Chemical resistance of samples was evaluated by immersion in 5% sodium sulfate solutions, 3% sulfuric acid solutions, and 0.05% sulfuric acid solutions, respectively, for up to 24weeks. The changes in mass, dynamic modulus, strength of the specimens, and the pH values of the solutions were monitored at regular time intervals. Test results are presented and discussed in conjunction with the companion results of ordinary Portland cement (OPC) mortars.