Study on Preparation and Properties of Cement-Based/Geopolymer-Polystyrene Composite Building Exterior Wall Insulation Materials

Abstract

With the continuous improvement of building energy-saving requirements, traditional insulation materials cannot meet current needs. New building insulation materials have become the focus of many researchers. The geopolymer was used as a matrix and combined with waste polystyrene foam (EPS) to form a geopolymerpolystyrene composite. The composite material is used to improve the thermal insulation performance of the cement exterior wall. XRD and morphological analysis of Qingdao kaolin were carried out by XRD and SEM. The optimum calcination temperature and time were determined to be 570 °C and 8 h, respectively. The geopolymer was subjected to hydration experiments based on the preparation of geopolymers from kaolin. The hydrated geopolymer was subjected to XRD analysis and morphology analysis. To obtain the best bonding performance of the geopolymer/polystyrene composite, polystyrene loading experiments were carried out. The resulting geopolymer-polystyrene composite was tested for thermal insulation properties with cement based on the optimum oligomer/polystyrene content ratio. Through the experiment, the following conclusions are obtained: When the ratio of cement to composite material does not exceed 8.7 and the solid solute density of hydrate formation is less than 280 kg/m3, the cement/geopolymer-polystyrene composite material satisfies the requirements of building exterior wall insulation materials. The increase of water cement ratio will reduce the strength of composite insulation materials. The increase of the content of cellulose, alkali water or air entraining agent can enhance the performance of the composite insulation material.