Abstract
The results reported in this paper deal with composites made with a non-toxic, water-based, inorganic polymer that not only offers high temperature resistance but also is environmentally friendly. Laminate composites and sandwich panels made with various types of fibers utilizing this new resin were evaluated for mechanical properties at various temperatures. This paper presents results pertaining to: (i) laminate composites made with glass, carbon, and steel mesh reinforcements, (ii) durability under wet-dry conditions, and (iii) behavior of fiber-reinforced sandwich structures. The results indicate that the inorganic resin has excellent potential in the composites industry. INTRODUCTIONDriven by demands of lower weight and cost, composites and sandwich structures have become extremely popular throughout the world. Lightweight composite materials have been used successfully in a variety of structural applications such as aircraft fuselages, ship hulls, cargo containers, high-speed trains, and turbine blades (Feichtinger, 1988; Kim, 1972). By combining various types of fibers and core types, structural sandwich panels and composites can be constructed for nearly any application. To join the various parts of the composite system, organic polymer resins are often utilized. However, many of the commonly used organic matrix materials soften and ignite at 400-600°C (Lyon et al., 1997). Consequently, structural elements are susceptible to rapid damage and collapse in the event of a fire. A new inorganic matrix, known as Geopolymer, was specifically developed for applications in which fire-resistance is a major concern. It is a two-part system consisting of an alumina liquid and a silica powder and cures at a reasonably low temperature of 150ºC or hardeners can be added to achieve room temperature curing. Once cured, the matrix can sustain temperatures up to 1000°C. It is compatible with carbon, glass, Kevlar®, steel, wood and inorganic materials such as clay bricks and concrete