h i g h l i g h t sOlive-stone biomass ash (OBA) was successfully tested as activator. OBA has alkaline properties suitable for alkali activated materials (AAM). OBA was used as unique activator for blast furnace slag (BFS). The effectivity of OBA was higher than KOH and similar to NaOH. OBA reduces the consumption of commercial chemical reagents in AAM.
Alkali-activated cements (AACs) technology is being widely investigated as a replacement for ordinary Portland cement (OPC) for environmental benefits. Blast furnace slag (BFS) is one of the most well known precursors used in AACs, having comparable properties to those of traditional OPC-based materials. AACs require alkali solutions, which are commonly based on a combination of sodium or potassium hydroxides with sodium or potassium silicates in high concentration. These alkali solutions represent the use of chemical reagents, and thus can have major environmental, health and economic impacts. Olive-stone (also known as olive pits) biomass ash (OBA) is a residue mainly composed of calcium and potassium oxides. Rice husk ash (RHA) is a rich silica residue from the combustion of rice husk. The combination of both residues can produce a good activating reagent for BFS-based AACs. In the present work, 100% waste-based ternary alkali-activated mortars (TAAM) based on BFS activated by OBA and RHA were developed. The mortars were assessed in terms of their dosage, curing treatment and time evolution. Finally an ecofriendly 100% waste-based TAAM with 67.39 ± 0.44 MPa after 90 days of curing at 20ºC is obtained and a complete microstructural characterization shows a dense and compact matrix with binding gel products labelled as C(K)-S(A)-H and C(K)-S-H.
O atendimento a norma de desempenho de edificações habitacionais é de grande importância, pois nela estão traduzidas as necessidades da sociedade brasileira no que se refere à aquisição de imóveis. Este trabalho tem por objetivo analisar a implementação da Norma de Desempenho - ABNT NBR 15575, em vigor em 2013 (parte 4 - Sistemas de vedações verticais internas e externas) em uma empresa construtora que possui um sistema de gestão da qualidade baseado no Programa Brasileiro de Qualidade e Produtividade do Habitat (PBQP-H). Foi desenvolvido um estudo de caso, dividido nas etapas: revisão bibliográfica, definição da amostragem, coleta de dados e análise de resultados. Os dados foram coletados através de entrevistas, análises documentais e observação com registros fotográficos do processo construtivo de vedação vertical externa em campo. Observou-se nos resultados que apesar da empresa ter conseguido atender a quase todos os requisitos da norma com o uso das Fichas de Avaliação de desempenho (FAD) e com a exigência dos relatórios de ensaios dos seus fornecedores, a vedação que a empresa executa na obra diverge em alguns pontos do que é estabelecido na documentação apresentada e analisada (FAD).
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