Assessment of geopolymer composites durability at one year age

Abstract

Geopolymers are important alternative materials for use in support of recycling and sustainability, and one of the most important properties is durability. While many studies perform durability tests 28 days after production, we carried out durability tests on a mixture of geopolymers starting 365 days after production. In this case, other conditions that occur until durability conditions are applied are taken into consideration. The geopolymer mixture consisted of metakaolin (90% by wt.) and boron waste colemanite (10% by wt.). The study investigated heat and wet-dry curing methods and polyolefin and polyamide fibre ratios (0.5, 1.0, and 1.5% by vol.) on durability. Durability issues related to concrete, such as long-term exposure to hydrochloric acid, freeze-thaw cycles, and abrasion were recorded. Results show that polyamide fibres provide better results than polyolefin fibres, the optimum polyamide fibre ratio was 1%, and the wet-dry curing method increased geopolymerisation more than heat curing. The Si-O-Al bonds were found to be stronger after wet-dry curing. All durability studies showed that the compact structure of the geopolymers withstood the durability tests performed one year after production. Scanning electron microscopy (SEM) analysis supports these results.