Natural pozzolan–based green geopolymer foam for thermal insulation
Open Access
- 30 September 2022
- journal article
- Published by Yildiz Technical University in Journal of Sustainable Construction Materials and Technologies
- Vol. 7 (3), 128-144
- https://doi.org/10.47481/jscmt.1182536
Abstract
The current study investigates the possibility of volcanic Tuff of Earth of Datça (ED) in Turkey to be used as an aluminosilicate source in producing a geopolymer foam for thermal insulation. An extensive evaluation of the effects of fine sand–to–pozzolan and Al powder–to–pozzolan ratios on the physical, mechanical, and thermal properties and morphology (porosity, average and maximum pore diameter, pore size distribution) of the pores were carried out. The sodium silicate and potassium hydroxide (12.5 M) solutions with an activator ratio of 2.5 were used as alkali activators, and Al powder was used as a foaming agent. Research results reveal that Earth of Datça is a suitable precursor for producing a geopolymer foam. Fine sand and aluminum powder contents are critical to the optimum foam structure. The addition of finely ground silica sand ensured the volumetric stability of the binder and prevented the collapse after swelling of the binder. The optimum Al powder–to–pozzolan ratio was determined as 0.5% because it gives higher physical, mechanical, and thermal properties due to the more homogenous microstructure with finer pore size and narrower pore size distribution lower degree of interconnectivity between the pores. Research results also show that the natural volcanic Tuff of Datça Peninsula as an aluminosilicate source gives promising results in the field of producing highly porous geopolymers with low thermal conductivity (0.087–0.134 W/mK), high porosity (72.3–82.6%) and an adequate compressive strength (0.40–2.09 MPa). This study contributes to the literature that Earth of Datça–based geopolymer foam may function well as an insulation material for building enclosures.Keywords
This publication has 44 references indexed in Scilit:
- Geopolymer foam concrete: An emerging material for sustainable constructionConstruction and Building Materials, 2014
- Evaluation of thermal conductivity, mechanical and transport properties of lightweight aggregate foamed geopolymer concreteEnergy and Buildings, 2014
- Analytical and numerical identification of the skeleton thermal conductivity of a geopolymer foam using a multi-scale analysisComputational Materials Science, 2014
- Combining multiple NDT methods to improve testing effectivenessConstruction and Building Materials, 2013
- Bulk composition and microstructure dependence of effective thermal conductivity of porous inorganic polymer cementsJournal of the European Ceramic Society, 2012
- Potassium geopolymer foams made with silica fume pore forming agent for thermal insulationJournal of Porous Materials, 2012
- Thermal insulating foamy geopolymers from perliteMinerals Engineering, 2010
- Evaluation of the Pozzolanic Activity of the Earth of Datça as a Building MaterialInternational Journal of Architectural Heritage, 2010
- The role of inorganic polymer technology in the development of ‘green concrete’Cement and Concrete Research, 2007
- Thermal Conductivity of Clay BricksJournal of Materials in Civil Engineering, 2004