Production and characterization of geopolymer materials for thermal insulation in constructions

In this doctoral thesis, mixtures were prepared adding powdered alumina oxide, and Kütahya Seyit Ömer Thermal Power Plant fly ash (FA-which is a waste material) in terms of recycling and waste evaluation into the solutions prepared with potassium hydroxide (KOH) and sodium metasilicate. Metallic aluminum powder as a foaming agent and various amounts of fumed silica (FS)were added to the slurry mixtures and cured by different curing times. The XRD patterns of all specimens show new crystal structures formed by dissolving the solution materials. Different crystal structures are observed in SEM images of Na2SiO3 / KOH activated and D10 coded samples. These crystal structures appear to evolve within the pores of 20-300 micrometers in size, which are formed within the alumina silicate gel structures confirmed by the EDX analysis. In the potassium hydroxide (KOH) activated specimens, the pore volume values were found to be in the range of from 0,02 to 0,013 cm3 for Vtotal. when the micro-pores ande meso-pores are evaluated as a percentage, the micro-pores are in the range of 0,08 - 0,84% and the meso-pores are in the range of 99,16 -99,92%. The pore volume values in the sodium silicate/potassium hydroxide activated (Na2SiO3/KOH) specimens, Vtotal are in the range of 0,04-0,007 cm3, micro-pores are in the range of 0,32-1,10%, and the meso-pores are in the range of 98,90-99,68%. In the D10 coded specimen, the pore volume value is 0,45 cm3, the micro-pore is 0,37%, and the meso-pore is 99,63%. Pore size distribution is in the range of 1,3-8,3 nm in KOH-activated specimens, 3,2-4,8 nm in Na2SiO3/KOH-activated specimens and 3,8 nm on D10-coded sample. When we look at the surface area values, in the KOH-activated specimens, a multipoint surface areas are in the range of 1,52-19,14 m2/g, a single point surface areas is in the range of 1,54-19,06 m2/g, and a total specific surface areas are in the range of 1,52-19,14 m2/g. In Na2SiO3/KOH activated specimens, the multipoint surface areas are in the range of 1,83- 0,20 m2/g, the single point surface areas are in the range of 1,85-10,11 m2/g, the total specific surface areas are in the range of 1,83-10,20 m2/g. In the D10 coded specimen, the multi-point surface area, a single point surface area, and a total specific surface area are 25,80, 25,84, and 25,80 m2/g, respectively. From the principle of Archimed, the weight of the dry specimen in the air, the suspended weight of the water-impregnated specimen in the water, and the weight in the air of the water-saturated specimen were measured. Using the measured data, in the Na2SiO3/KOH activated specimens, the dry unit weights from 1219 to 2073 kg/m3, the water uptake from 5,7 to 33,3%, the apparent open porosity from 11,8 to 40,6%, the closed porosity from 6,7 to 16,5%, and the total porosity 18,5-52,5% were calculated. For the D10 coded specimen, following physical values are calculated; dry unit weights: 571 kg/m3, water Absorption: 83,9%, apparent open porosity: 47,9%, closed porosity: 29,3%, and total porosity: 77,2%. When we look at the FT-IR analyzes, the bands found in all specimen at 950-1100 cm-1 show that asymmetric strethcing oscillations originating from the Si-OM bonds (M = Si, Al, K, Na) were attributed to the new amorphous silica gel formation by dissolving the fly ash, and the geopolymerization reaction. In addition, bands showing symmetrical strethcing oscillations of Si-O-Si and Al-O-Si attributed to the amorphous formation of semi-crystalline alumina silicate materials (~ 760-560 cm-1) to confirm the crystal structures observed in the XRD show that reconstruction of fly ash. In Na2SiO3/KOH activated specimens, the NK342 coded specimen is the best result with the heat transfer coefficient (λ) 0,190 W/m ºK. The heat transfer coefficient of the D10 coded specimen is 0,085 W/m ºK. In addition, the water vapor permeability of D10 coded specimen is 3 μ and the compressive strength is 0,6 N/mm2. Test done by a method similar to TS EN ISO 11925-2 the single flame ignitability (SFI) did not flame on the product and the flame was cut off when removed from the surface of the flame source. At the same time, the test sample was exposed to open flame for 30 seconds and the height of the burning part was measured approximately 9 cm and evaluated as "B2 class".It is a material that can be processed quickly because it can be cut easily and smoothly with saw, model knife or similar tools. Silicone adhesive and cement-based thermal insulation plate adhesion reaction has been very positive. In addition, the application of heat insulation plate plaster mortar, there is no plaster retention, cracking and tearing on the surface did not occur. Therefore, it can be said that the adhesion property is very good. In conclution, Kütahya Seyit Omer thermal power plant waste fly ash (FA) was found to be economically and technologically feasible used geopolymer material production for thermal insulation in construction. Both the characterization studies and the economic analysis results of the obtained polymeric thermal insulation material reveal the advantages of this material over those of the commercial ones sold. Thus, it can be said that a commercial polymeric thermal insulation material for the construction sector has been produced under laboratory conditions in terms of clean environment, low carbon emission, domestic resource-based and relatively low costed production, as well as contributing to current deficit.