Variability in the environmental impacts of aggregate production

International audienceWhile LCA (Life Cycle Assessment) is considered to yield either generic or regionally/technologically specific data on products, this method's implementation can reveal a certain variability due to the nature of the local industrial process as well as to heterogeneous site characteristics in the case of natural aggregate production. Energy consumption and the release of atmospheric emissions from aggregate production processes have been investigated in this study at three quarry sites, which encompass two types of rock (and include explosives). This paper describes the methodology adopted for the specific local production investigation and offers results for the three quarry sites using seven indicators derived from the LCA framework. Site characteristics and differences have been assessed in terms of plant equipment and off-road vehicles, and a detailed description is provided of the grading conducted onsite. It is found that fine grading consumes more energy for production, given the fact this type of grading is recycled inside the plant. This assessment has been performed for 1 ton of aggregate produced during 1 year and with distinction in grading category. Results indicate that the discrepancy in local energy consumption due to site differences lies within an interval between −9.5% and +13.7%, while the interval for impacts is situated at −24.5% to +27.5% whereas for global warming potential the range is from −15.4% to +12.9% as a maximum. Explosives are assumed to contribute less than 1% to the total impacts. Both the electrical energy and fossil fuel consumption ratios are displayed. The upstream processes specific to electricity production significantly contribute to human toxicity potential and ecotoxic potential indicators, as for other indicators and also diesel production (all indicators) the contribution is in proportion close to site results ones. However, this study indicates that an environmental load decrease may be investigated with respect to quarry processes as well as equipment age and use