Fire Resistance of Geopolymer Foams Layered on Polystyrene Boards

Abstract

Geopolymer foams are excellent materials in terms of mechanical loads and fire resistance applications. This study investigated the foaming process of geopolymers and foam stability, with a focus on the fire resistance performance when using polystyrene as the base layer. The main purpose is to define the influence of porosity on the physical properties and consequently to find applications and effectiveness of geopolymers. In this study, lightweight materials are obtained through a process called geopolymerization. Foaming was done by adding aluminum powder at the end of the geopolymer mortar preparation. The interaction between the aluminum powder and the alkaline solution (used for the binder during the mixing process) at room temperature is reactive enough to develop hydrogen-rich bubbles that increase the viscosity and promote the consolidation of geopolymers. The basic principle of thermodynamic reactions responsible for the formation of foams is characterized by hydrogen-rich gas generation, which is then trapped in the molecular structure of geopolymers. The geopolymer foams in this study are highly porous and robust materials. Moreover, the porosity distribution is very homogeneous. Experimental assessments were performed on four specimens to determine the density, porosity, mechanical strength, and thermal conductivity. The results showed that our geopolymer foams layered on polystyrene boards (with optimal thickness) have the highest fire resistance performance among others. This combination could withstand temperatures of up to 800 °C for more than 15 min without the temperature rising on the insulated side. Results of the best-performing geopolymer foam underline the technical characteristics of the material, with an average apparent density of 1 g/cm3, a volume porosity of 55%, a thermal conductivity of 0.25 W/mK, and excellent fire resistance.

Physico-chemical and Mechanical Properties of Eco-friendly Ultra-lightweight Geopolymers Containing Silica Sand Fluor and Calcium Carbonate

“…SEM images exhibited high percentages of unreacted silica sand flour due to the high crystallinity of silica in the form of quartz phase and the high-substitution volume of GGBFS. These results are atterns for the same mixes [6]. SEM images at different magnification values revealed high compaction and uniform phases between geopolymer products and silica sand flour due to the high fineness of silica sand flour due to the absence of cracks at the interfacial transition zone [50].…”

“…The modern form of geopolymeric material used in insulation is lightweight Geopolymers [5]. Lightweight Geopolymers are low-density materials that have good chemical, physical, and thermal properties with low thermal conductivity and fire resistance [6], appropriate compressive strength, low toxicity, low cost of transport, low carbon dioxide (CO 2 ) emission, low energy consumed in the production process [7,8], lower setting times, rapid hardening, and low shrinkage [9].…”

The Military and Civilian Applications of Geopolymers

“…Along with high thermal resistance, thermal conductivity of geopolymers is very low, making geopolymers an excellent material for heat insulation or passive fire protection, especially in foamed form (achieved by foaming agents, such as powdered aluminum or hydrogen peroxide) [24,25].…”

“…Spraying geopolymer coatings on OSB boards improves their durability in fire (by tens of minutes at minimum), which gives more time to extinguish the fire or evacuate people from the building. Geopolymer foams may also be used to protect internal steel beams from losing their mechanical properties and collapsing [24,25,44].…”

Anisotropic Heat Transfer in Plane of Carbon Fabrics Reinforced Geopolymer Composite

“…Geopolymers emerge as the alternative eco-friendly material because of durability, flexural strength, and high temperature withstanding behavior [2,3]. However, geopolymer is more brittle in nature, which hinders its application in various areas [4,5]. This could result in failures in civil structure [6] in areas of the construction and building sectors.…”