Preparation and Investigation of Geopolymers Generated From Construction, Demolition and Industrial Wastes

Abstract

Geopolymers are inorganic amorphous aluminosilicate materials, which can be produced by the alkali activation of materials with high aluminum and silicon content. In this research, we prepared geopolymer samples obtained from construction and demolition (C&D) waste materials (brick powder and concrete powder), as well as industrial waste material (aluminum dross), and we investigated them using different test methods. Density, particle size distribution and chemical elemental composition were determined on the dried powdered waste materials, and microstructural observations were also made using a scanning electron microscope (SEM) technique. To prepare the geopolymer sample mixtures of sodium-hydroxide and sodium silicate, we used an alkali activator solution at different concentrations (4 M, 8 M and 12 M). We used Fourier Transformation Infrared Spectroscopy (FTIR) to reveal new phases in geopolymer samples. Compression strength was determined after 7 days and after 28 days. In the cases when aluminum dross was used, a gas-forming reaction took place in the geopolymer pastes; therefore, foamed geopolymer was produced. According to these results, the used C&D and industrial wastes may be potential raw materials which could be used to prepare geopolymers.