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Operational energy comparison of concrete and foamed geopolymer based housing envelopes

Abstract:

The present article provides an operational energy comparison of modern concrete and foamed geopolymers as envelope materials for single unit housing in Ecuador. The study is performed by replacing the concrete material used in the walls and roof elements with foamed geopolymer components. Residential building sector requires around 35.6% of the total energy demand in Ecuador. For this reason, efforts on building practices improvement are relevant for the Ecuadorian society. The foamed geopolymers are a mixture of aluminosilicate material obtained from Ecuadorian natural zeolite, group of alkaline activators and the foamed agent that when mixing the raw materials and obtain the geopolymer. To assess the potential use of foamed geopolymers as construction material, the annual energy demand for a social interest dwelling was obtained through simulation with EnergyPlus. Prefabricated Insulated Concrete Forms was established as the construction practice for the building model. Annual energy simulations were performed considering two Ecuadorian representative weathers, to Guayaquil and Quito locations. Material properties of foamed geopolymers ware acquired by own experimental facilities. Thermal conductivity was obtained with the use of the hot plate method, while specific heat by means of differential scanning calorimetry (DSC) analysis. This analysis uses foamed geopolymers obtained from two procedures. Thus, these proposed materials presented low density, low thermal conductivity, and acceptable compressive strength values. Finally, an assessment of natural geopolymers as a concrete replacement is presented, including a thermal characterization, and a sustainable construction evaluation. The findings affirm the key role of material selection in construction practices. Reductions around 4.0% in annual electricity demand was achieved for Guayaquil case, while energy consumption decreases around 1.3% for Quito.