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Mortars are cement-based materials used mainly to coat and settle construction blocks. In addition to cement, their composition usually includes hydrated lime, sand, and water. The hydrated lime is important to improve the mortar workability. However, lime has a high commercial cost, and its production causes emission of CO 2 , a major responsible for global warming. Therefore, the purpose of this work was to investigate the possibility of total or partial replacement of hydrated lime in mortars by a kaolinitic clay with ideal plasticity parameters. Clay amounts of 0, 25, 50, 75, and 100 wt-% were used as replacement of hydrated lime in mortars. The results showed that with up to 50 wt-% of hydrated lime replacement, it is perfectly feasible to fulfil with technological parameters of standards.

Este trabalho apresenta resultados sobre durabilidade de artefatos cerâmicos vermelhos incorporados com resíduo de granito, produzidos no pólo cerâmico de Campos dos Goytacazes-RJ. Inicialmente, para avaliação e análise do desempenho dos cerâmicos, são apresentados resultados da caracterização da massa argilosa e do resíduo de granito e, também, os efeitos da degradação do cerâmico obtido com a adição do resíduo de granito na massa argilosa. A massa argilosa foi coletada numa Indústria Cerâmica da região de Campos dos Goytacazes, RJ, e o rejeito é oriundo da região de Cachoeiro de Itapemirim, ES. As misturas foram feitas adicionando-se 0%, 5% e 10% de rejeito, em peso, até homogeneização da massa argilosa para posterior obtenção de corpos de prova prismáticos. Os corpos de prova foram submetidos a secagem e queima a 500 °C, 700 °C e 900 °C. De um lote de amostras foram obtidas as propriedades tecnológicas. Em outro lote, as amostras foram levadas ao equipamento de degradação e a ciclos de umidade para promover a alteração do cerâmico. Foram consideradas até 1500 h de lixiviação contínua no equipamento, e 50 e 150 de ciclos de umidade. Através da microscopia eletrônica de varredura foram observadas as modificações na microestrutura do material antes e depois da degradação. Os resultados mostram que certa quantidade de incorporação de resíduo tem influência considerável na evolução da degradação. Além disto, são notadas maiores resistências à degradação no material incorporado.

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The recycling of industrial wastes such as those produced during processing of ornamental stones is a relevant procedure to mitigate the possibility of environmental pollution. In the present work the durability of soil-cement blocks incorporated with an ornamental granite stone waste was investigated by means of water immersion durability tests as indicated by the Brazilian norm. Preliminarily, the granite waste was characterized by its chemical composition, particle size and X-ray diffraction. The incorporation was carried out in a mixture with limestone, sand, water and cement. After the durability tests, the soil-cement block were tested for the change in strength and water absorption. The results showed a loss in strength for 90 days of immersion cycles together with a relatively small gain in water absorption. The block composition with 60% of waste was able to attend the norm by apparently developing less porosity than the 65% waste incorporated block.

Brazil is one of the largest producers of pineapple in the world, which, in addition to bringing substantial benefits, contributes to increasing waste generation in the stages of processing, aiming at its consumption. The Brazilian environmental legislation has been increasingly more restrictive with respect to the disposal of solid waste, whether domestic, industrial or agro-industrial, which has stimulated studies related to the use of these materials in several matrices. This study aimed to evaluate the potentiality of using the natural fiber of pineapple (Ananas comosus), extracted from its leaves, as reinforcing material in cementitious composites. For this purpose, natural fiber extracted from the pineapple crown was incorporated in different percentages in relation to the cement mass: 0, 2.5, 5, 7.5 and 10%, and the fibers obtained were submerged in aqueous NaOH solution with 5% concentration in volume, for 1 h at room temperature. The following variables were evaluated: consistency, water retention, incorporated air, mass density in hardened state, mechanical strength, water absorption by immersion and capillarity, besides verifying the influence of the mode of fiber incorporation. It was observed that the treatment with NaOH solution and the percentage of natural pineapple fiber incorporated in up to 5% in relation to the cement mass form mortars with technological feasibility.

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