Environmental footprint study of mortar, render and plaster formulation / Studie über die Umweltauswirkungen von Mörtel - Mauermörtel, Außenputzmörtel und Innenputzmörtel

A comparative environmental assessment study focusing on the stages of mortar production and carbonation through hardening has been conducted by the European Lime Association in collaboration with mortar producers from various EU countries on 17 formulations of mortars, renders and plasters. The results of the “cradle-to-gate” for mortar and renders indicated that: There are no significant differences between products with low and high lime contents and depending on the lime content in the products, the contribution of the hydrated lime to the different environmental indicators can range between 0 % and about 20 %. However, there are clear differences in the environmental footprints of gypsum or lime based plasters. Based on the plaster composition investigated in this study, it appears that lime based plasters have the lowest environmental footprint for some of the impacts (primary energy consumption, abiotic depletion and water eutrophication), whereas for the remaining indicators the gypsum based plasters have the lowest environmental footprint. Depending on the lime content in the plasters, the contribution of the hydrated lime to the different environmental indicators can vary in a wide range, i. e. between 0 and 40 %.
The differences in the environmental impacts of mortars, renders and plasters produced in integrated or non-integrated mortar plants are generally rather small The lime carbonation process lowers the overall carbon footprint during the first period of the use phase of the mortars in buildings. This impact shall be taken into account in holistic LCA studies. If not, this leads to a wrong interpretation of the environmental impact of the mortars.