Dosage of eco-efficient self-compacting microconcretes containing ornamental stone wastes

• Ano de defesa: 2022
• Autor(a) principal: Souza, Ariel Miranda de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Engenharia Civil
• Palavras-chave em Português: Concreto autoadensável; Sustentabilidade; Concreto leve; Rochas ornamentais - Reaproveitamento; Materiais e Componentes de Construção
• Link de acesso: https://locus.ufv.br//handle/123456789/29854; https://doi.org/10.47328/ufvbbt.2022.127

The present work sought to evaluate the effects of incorporating a high concentration of waste from the processing of ornamental stone as a filler in self-compacting and lightweight self- compacting microconcrete containing expanded polystyrene waste through the evaluation of its physical-chemical, mechanical and eco-efficiency properties. The dosage of the concretes was done by the particle packing method to obtain the limits of the filler/cement, powder/total solids and lightweight aggregates/total aggregates ratios for the production of mixtures following a second-order composite experimental design. The samples produced were tested in fresh and hardened states. Eco-efficiency performance analyzes were carried out by Binder Intensity and assessment of the environmental impacts generated in the production of each material in the mixtures produced. The results, evaluated through response surfaces, showed that replacing cement with waste reduced the microconcretes mechanical strength but increased eco- efficiency compared to other self-compacting concretes of similar mechanical strength. In lightweight microconcrete, the residue increased workability and viscosity and reduced water consumption, helping to avoid segregation. However, despite the addition of lightweight aggregates reducing the density of microconcretes, it was not possible to stabilize the mixture for fixed spreading, with segregation occurring in mixtures with high levels of lightweight aggregates. Therefore, the residue can be promoted to a co-product for application in civil construction as a stabilizing agent in self-compacting microconcretes, capable of reducing the cement content and consequently the embodied CO 2 emissions, obtaining more eco-efficient matrices without significant losses in its technological properties. Keywords: Self-compacting concrete. Eco-efficient concrete. Sustainability. Ornamental stone waste. Microconcrete. Lightweight self-compacting concrete.