Assessment of the embodied energy and carbon footprint of vibration-compacted adobe brick

Abstract

The resort to local materials and the development of appropriate and/or environmentally friendly materials are solutions envisaged to contribute to the achievement of the SDGs by 2030. The added or qualitative value of these local materials for environmental protection is measurable through environmental impact indicators. This study assessed the embodied energy and carbon footprint of a vibration-compacted adobe brick measuring 40 × 20 × 10 cm. The first step was extracting the soil from the Sabtenga quarry (12°29′17.45″N; 1°40′33.71″W) near Ouagadougou, then formulating and drying specimen of vibration-compacted adobe brick. Next, an inventory of the various processes at different stages in the life cycle of the vibration-compacted adobe brick was made considering local data and, failing that, on data from some specific studies. Thus, based on life cycle analysis, from cradle to grave, two environmental impact indicators were assessed. The values obtained are 0.291 MJ/kg for embodied energy and 4.1411 kg CO₂eq for the carbon footprint. Analysis of the inventory has shown that the majority of impacts were observed during the PRODUCT stage, with a figure of 94.34 % for embodied energy and 99.84 % for carbon footprint and that the raw material (soil) transportation process is responsible for significant primary energy consumption and greenhouse gas emissions, mainly CO₂. Moreover, it is recommended to further the study by taking into account the limitations encountered.