ABSTRACT Partial replacement of Portland cement by industrial waste or materials of natural origin can improve the mechanical strength of concrete and mortar and reduce production cost. In this context, ash from burning bamboo appears as a potential material for use, as it is natural with a renewable source and fast growth, which presents a higher concentration of silica in the outer walls of the stalks. Therefore, the objective of this work is to evaluate the use of bamboo stalk ash (Bambusa Vulgaris) as a partial replacement for Portland cement. For this purpose, bamboo ash was produced at three calcination temperatures (500ºC, 600ºC and 700ºC). The ashes were not characterized as pozzolans based on their chemical composition, however the ash produced at 600ºC obtained a performance index higher than that established by the Standard. The hydration of cement partially replaced by this ash was evaluated, in proportions of 0%, 6%, 10% and 14%, in relation to its mass. Mortars with the same replacement proportions were evaluated in the fresh state and hardened. The consistency in the fresh state remained constant at 227 mm, while the compressive strength, in the hardened state, increased by 15% with the addition of bamboo stem ash.

ABSTRACT The civil construction industry is responsible for the emission of carbon dioxide (CO2), for each ton of cement produced, approximately one ton of carbon dioxide is emitted into the atmosphere. Therefore, the present work has as general objective to study the technical feasibility of using the Blast Furnace Slag (EAF), cooled instantly as a substitute for Portland cement. For this work, clinker, standardized sand, plaster, drinking water and EAF were used as materials. As a methodology, the materials were milled to the desired granulometry, which passed through the 0.075mm sieve. After this process, the characterization of these materials started, followed by the replacement of clinker, in the contents of 5, 15, 30, 50 and 75% by EAF. The results of this substitution showed that the tailings were characterized as an excellent by-product in the manufacture of cement, presenting characteristics for large-scale use in search of reducing CO2 emissions.

RESUMO A indústria de construção civil é uma das responsáveis na emissão de gás carbônico (CO2), para cada tonelada de cimento produzido é emitido na atmosfera aproximadamente uma tonelada de gás carbônico. Portanto, o presente trabalho tem como objetivo geral estudar a viabilidade técnica do uso do da Escória de Alto Forno (EAF), resfriada instantaneamente como substituição ao cimento Portland. Para este trabalho utilizou-se como materiais o clínquer, areia normatizada, gesso, água potável e EAF. Como metodologia dos ensaios foi realizado a moagem dos materiais, até a granulometria desejada, passante na peneira 0,075mm. Após esse processo iniciou-se caracterização desses materiais, sendo seguido, da substituição do clínquer, nos teores de 5, 15, 30, 50 e 75% pela EAF. Os resultados dessa substituição mostraram que o rejeito, caracterizou-se como um excelente subproduto na fabricação do cimento, apresentando características para o emprego em larga escala em busca da diminuição da emissão do CO2.