Within the scope of the present study the cold-bonding process was used for the recycling of waste filter powder which was mixed with two different binders in different concentrations; alumino-silicate cement and potassium water glass, and combinations of these two materials, and hardened at room temperature. Selected samples were also fired at 1200 °C. Tests to determine tensile and compressive strength, density and porosity, as well as dilatometry and SEM analyses, were performed. The compressive strengths of the non-fired samples were in the range from 0.8 to 2.4 MPa, where as after firing strengths of up to 36 MPa were obtained. In the case of combinations of the two binders, shrinkage as well as expansion on firing were less pronounced. Results are partially connected to the project since knowlegde on geopolymerization by using water glass was applied.
COBISS.SI-ID: 2102887
Recent innovations in geopolymer technology have led to the development of various different types of geopolymeric products, including highly porous geopolymer-based foams, which are formed by the addition of foaming agents to a geopolymer fly-ash based matrix. These agents decompose, or react with the liquid matrix or oxygen in the matrix, resulting in the release of gases whichform pores prior to the hardening of the gel. The hardened structure has good mechanical and thermal properties, and can therefore be used for applications in acoustic panels and in lightweight pre-fabricated components for thermal insulation purposes. This study presents the results of the pore-forming process in the case when two different foaming agents, i.e. aluminium powder amounting to 0.07, 0.13 and 0.20 mass. % and H2O2 amounting to 0.5, 1.0, 1.5 and 2.0 mass. %, were added to a fly-ash geopolymer matrix. Highly porous structures were obtained in the case ofboth of the investigated foaming agents, with overall porosities up to 59% when aluminium powder was added, and of up 48% when H2O2 was added. The mechanical properties of the investigated foams depended on their porosity. In the case of highly porous structures a compressive strength of 3.3 MPa was nevertheless achieved for the samples containing 0.2% of aluminium powder, and 3.7 MPa for those containing 2.0% of H2O2. Papaer was prepared and reviewed at the end of 2015, but accepted for publication in January 2016.
COBISS.SI-ID: 2168679