Life cycle assessment of the ornamental stone processing waste use in cement-based building materials

摘要

Laboratory technical studies demonstrate the feasibility of using the ornamental stone processing waste (OSPW) for construction and building materials manufacturing. However, regarding the environmental aspect, there is still the need to justify its use quantitatively. Thus, this study presents the life cycle assessment (LCA) of using OSPW for cement-based building materials manufacturing, aiming to assess OSPW influence on environmental impact indicators (global warming potential, embodied energy and total impact). Altogether, 127 mixtures are analyzed, such as mortars, concretes, masonry and paving blocks. The impacts of OSPW drying and logistics are presented, as well as the impacts of the process (burning) to produce the heat-treated waste (HTOSPW). The results indicate that OSPW is a good alternative to reduce environmental impacts in the analyzed scenario (Espirito Santo (ES) state - Brazil), as a replacement for limestone filler, sand or stone dust. OSPW could be used as a cement partial replacement and presented satisfactory environmental results at high replacement levels (over 50%) in the production of self-compacting concrete, rendering and masonry mortars. The results also show that the artificial drying alternatives greatly increase the OSPW impact. Regarding the production of the mixtures, cement replacement was the approach most commonly used, causing a reduction in environmental impact indicators of 7.7 to 9.0% for each 10% of OSPW use. (C) 2020 Elsevier Ltd. All rights reserved.