Properties of Basalt Fiber-reinforced Lightweight Geopolymer Mortars Produced with Expanded Glass Aggregate

Abstract

Geopolymers are new-generation construction materials that have attracted attention recently and can be an alternative to cement. In the production of these materials, aluminosilicate powder materials are used together with alkali or acid solutions. Geopolymers have different types of superiorities, such as rapid strength gain, high mechanical properties and good durability. This experimental study investigated the properties of expanded glass aggregate-bearing Class F fly ash-based lightweight geopolymer mortars. The fresh unit weight, water absorption capacity, compressive strength and high-temperature resistance (upon exposure to 900°C) of the mortars were determined. In addition, basalt fiber addition's effects on these properties were investigated. The inclusion ratios of basalt fiber were 0.1%, 0.2% and 0.4% by volume. The compressive strengths of fiber-free lightweight mixture and mixtures, including 0.1%, 0.2% and 0.4% basalt fiber, were found to be 8.2, 8.9, 9.0 and 8.0 MPa, respectively. The compressive strength of all lightweight mortars increased between 61.3% and 76.4% after the high-temperature effect. The results proved that it is possible to produce expanded glass aggregate-bearing lightweight geopolymer mortars with acceptable mechanical properties.