Mechanical property and microstructure characteristics of geopolymer stabilized aggregate base. (10th December 2018)

• Record Type: Journal Article
• Authors: Hu, Wei; Nie, Qingke; Huang, Baoshan; Su, Aiwu; Du, Yong; Shu, Xiang; He, Qiang
• Is Part Of: Construction & building materials. Volume 191(2018)
• Page Start: 1120
• Page End: 1127
• Publication Date: 2018-12-10
• Subjects: Geopolymer -- Red mud -- Class F fly ash -- Stabilized aggregate base -- Mechanical properties; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.10.081
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: This research explored the possibility of utilizing geopolymer as base stabilizer. Two key factors for the geopolymer stabilized base were investigated. Different exothermic curves were identified for various stabilizers. Abstract: With its potential to replace ordinary Portland cement, geopolymer has been receiving more and more attention in cement industry as well as geotechnical engineering. However, research is mainly focused on use of geopolymer to make geopolymer concrete or masonry bricks, little has been done about its application as a stabilizing agent in pavement base materials. This study explores the feasibility of using geopolymer-stabilized base material in pavement base layer. Two industrial wastes, class F fly ash and red mud, were utilized to synthesize the geopolymer stabilized aggregate base, and two conventional stabilizing agents, cement-fly ash and lime-fly ash, were also included for comparison purpose. Three curing conditions were adopted to investigate two key factors in the geopolymerization process, temperature and water. Test results show that a standard curing condition was adequate for strength development of geopolymer base samples with a compressive strength close to that of the cement-fly ash base sample. An increase in temperature from 20 °C to 38 °C accelerated the strength development of both geopolymer base samples, whereas a decrease in relative humidity from 98% to 45% significantly impaired the strengths of all conventional and geopolymer base specimens, indicating that a wet condition was still necessary for geopolymer stabilized base layer. According to the test results, geopolymer stabilized aggregate bases showed promise to be used as a stabilizing agent in flexible pavement applications.