Investigation on properties of geopolymer mortar using preheated materials and thermogenetic admixtures

• Published in: Construction & building materials 2017-01, Vol.130, p.146-155
• Main Authors: Nguyen, Khoa Tan, Le, Tuan Anh, Lee, Jaehong, Lee, Dongkyu, Lee, Kihak
• Format: Article
• Language: English
• Subjects: Analysis; Fly ash; Geopolymer mortar; Hot pack; Lime; Mechanical properties; Mortar; Preheated; Quicklime; Self-cured geopolymer
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2016.10.110

•Proposing two new alternative curing method are using preheated materials and thermogentic admixtures.•For using preheated materials, a larger amount of preheated materials results in a higher compressive strength.•For using thermogentic admixtures, quicklime is more efficient than hot pack material.•The suggested amount of quicklime is about 3–5% of fly ash by mass. Heat curing in an oven is the traditional method to obtain mechanical properties of geopolymers. This characteristic has significantly affected operations in terms of construction and energy consumption. The target of this paper is proposing alternative curing methods namely self-cured technologies for fly ash based geopolymer materials that are cured in ambient conditions without use of a heat resource. Two alternative methods are to use three different mixing processes with preheated materials and to use two thermogenetic admixtures (hot pack material and quicklime). The results show that for the mixing processes, a larger amount of provided heat energy results in a higher compressive strength of the geopolymer mortar (GM). For the use of a thermogenetic admixture, the results from compressive strength testing, Scanning Electron Microscope (SEM), energy dispersive X-ray analysis (EDX) micrographs and X-ray diffraction (XRD) analysis confirm that quicklime is more efficient than hot pack material. In the case of using quicklime, the suggested amount is about 3–5% of fly ash by mass.