Journal article
Effects of heat and pressure on hot-pressed geopolymer
Manufacturing Engineering, Department of Mechanical Engineering, Technical University of Denmark1
Department of Mechanical Engineering, Technical University of Denmark2
Shiraz University3
Delft University of Technology4
Biotherapeutic Engineering and Drug Targeting, Department of Health Technology, Technical University of Denmark5
Department of Health Technology, Technical University of Denmark6
Hot-pressed geopolymers have been introduced as ultra-high early strength ceramic-like materials with an almost pore-less structure. This study investigates the combined effects of pressure and heat on geopolymerization kinetics, microstructure, physical properties, and mechanical performance of geopolymers.
The results demonstrate that about 65% of the trapped air is easily removed from the fresh geopolymer matrix using an initial impact pressure. When the pre-compacted matrix is subjected to the hot-pressing, it is further densified in the range of 1–10% as a result of continuous free-water evaporation and compaction.
This process not only reduces the size and volume of porosity but also changes the continuous pore network to a closed one. Besides, the increase in hot-pressing promotes higher geopolymer gel formation and accelerates the polycondensation which possesses relatively high mechanical strength up to 160 MPa immediately after the processing.
Collectively, these results demonstrate that the hot-pressing technique is a promising processing route for designing geopolymer with a diverse range of mechanical properties in a short and fast manner.
Language: | English |
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Year: | 2020 |
Pages: | 117106 |
ISSN: | 18790526 and 09500618 |
Types: | Journal article |
DOI: | 10.1016/j.conbuildmat.2019.117106 |
ORCIDs: | Ranjbar, Navid , 0000-0001-8566-3863 and Mehrali, Mehdi |