Influence of Early Microwave Curing on Performance of Slag-Based Geopolymer Mortars

In this article, an experimental study was conducted to examine the effect of curing time and microwave power on the compressive strength of early microwave-cured slag based geopolymers. Geopolymers have the potential to serve as an environmentally friendly substitute for cement-based building materials, and the use of microwave curing to geopolymers holds the promise of substantial strength improvement. Different microwave curing energies (300 - 800 Watts) were utilized at varying durations (10 - 60 minutes) on demoulded mortar specimens after one day. After that, compressive strength tests were conducted on both the cured and uncured specimens at three different ages: 1, 7, and 28 days. Results indicated that microwave curing could increase the strength about 10 times (36,47 MPa) in 1 day which is almost equal to the 28 days strength of uncured specimens. Based on the performed SEM-EDX results and visual inspections there may be a correlation among EDX results, color changes and compressive strength values. High energy level such as 800-Watt caused decay in samples and durability problems by decreasing the strength at late ages; Therefore, it is recommended to not apply such high energies to slag-based geopolymers.