High-Strength Geopolymer Using Fine High-Calcium Fly Ash

• Published in: Journal of materials in civil engineering Vol. 23; no. 3; pp. 264 - 270
• Main Authors: Chindaprasirt, P, Chareerat, T, Hatanaka, S, Cao, T
• Format: Journal Article
• Language: English
• Published: Reston, VA American Society of Civil Engineers 01.03.2011
• Subjects: Aggregates and other concrete constituents; Applied sciences; Buildings. Public works; Cement concrete constituents; Concrete additives (fillers, pozzolanic and hydraulic materials); Drying; Exact sciences and technology; Fineness; Fly ash; Materials; Mortars; Pastes; Plastics; Sodium hydroxide; Strength; TECHNICAL PAPERS; Workability; High performance; Scanning electron microscopy; Mixing; Mortar; Calcium; Construction materials; Mechanical properties; Fly-ash fineness; Polymer; Shrinkage; Geomaterials; Experimental study; Dewatering; Inorganic polymer; Flow; Fly ash; Geopolymer; Drying shrinkage; Setting time; High strength; Geomaterial; Drying
• ISSN: 0899-1561; 1943-5533
• DOI: 10.1061/(ASCE)MT.1943-5533.0000161

In this paper, the synthesis of high-strength geopolymer using fine high-calcium fly ash was studied. The effect of fineness of fly ash on the setting time of geopolymer paste, workability, strength development, and drying shrinkage of geopolymer mortars made from classified fine high-calcium fly ash was investigated. Air-classified fly ash with three different finenesses—coarse original fly ash (CFA), medium-fineness fly ash (MFA), and fine fly ash (FFA)—from the Mae Moh Power Station was used for this study. The heat-cured geopolymers were activated with sodium hydroxide (NaOH) and sodium silicate. A small amount of water was incorporated for workability. The results indicate that the setting time of paste decreases with an increase in fly-ash fineness. The flow, strength, and drying-shrinkage characteristics of mortars were improved using fine fly ash. Geopolymer mortars with high 28-day compressive strength of 86.0 MPa were obtained.