Resistência mecânica de compósitos cimentícios leves utilizando resíduos industriais e fibras de sisal

Abstract

R ESU M OA valorização de materiais alternativos incorporados com resíduos como opção ao convencional deve possibilitar a geração de um produto com qualidade, estética, produtividade e com potencial de reduzir impactos da poluição ambiental. Este trabalho foi realizado com o objetivo de desenvolver elementos construtivos para forro e divisórias, a partir de matrizes cimentícias com incorporação de resíduos industriais (resíduo cerâmico, etil vinil acetato -EVA) e fibras de sisal. Desenvolveram-se técnicas de moldagem em matrizes cimentícias autoadensáveis e se avaliou a resistência mecânica dos novos compósitos. Uma placa com resíduos de EVA foi produzida e, através de trabalhos de reologia, encontrouse a pasta matriz de revestimento desta placa, com teor adequado de adições pozolânicas e aditivo superplastificante. Avaliaram-se as resistências mecânicas das placas, da pasta matriz de revestimento encontrada, com e sem adição de fibras, e do novo compósito formado pela união desses dois elementos. Utilizou-se a técnica de alinhamento de fibras com o intuito de incrementar resistência ao novo compósito leve. A adição da matriz com fibras alinhadas melhorou a resistência a flexão do novo compósito.Palavras-chave: elementos construtivos, flexão, reologia, fibras de sisal e resíduos industriais Mechanical resistence of lightweight cement composites utilizing industrial residues and fibers of sisal A B ST R A C T The appreciation of alternative materials incorporated in waste as an option to conventional material should enable to generate a product with quality, aesthetics, productivity and reduce the potential impacts of environmental pollution. This study aims to develop constructive elements for ceilings and walls from cementitious matrix incorporating industrial waste (ceramic waste, ethyl vinyl acetate -EVA) and sisal fibers. Moulding techniques to produce self-compacting cementitious matrices were developed and the strength of the new composites were evaluated. A plate with EVA waste was produced and through rheology studies, a matrix plaster for coating of plate surface was found, with appropriate content of pozzolanic and superplasticizer additions. The mechanical resistance of the plates, the pulp coating matrix, with and without added fiber and the new composite formed by the union of these two elements was assessed. The technique of fiber alignment with the aim of increasing resistance of the new lightweight composite was used. The addition of the matrix with aligned fibers improved the flexural strength of the new composite.

EVA Lightweight Concrete Reinforced with Piassava Fiber

“…4B, where an increase of 75% in tensile strength is observed with respect to the reference matrix. With respect to mixing with EVA, the addition of fiber increased the tensile strength by up to 83%, indicating that it is possible to compensate, with the addition of fibers, the strength reduction caused by the introduction of lightweight aggregate, confirming the results obtained by [12]. In brittle matrices under traction, the fibers connect the microcracks reducing the unstable propagation of the same and increasing the toughness of fracture and post-cracking resistance of the material [18].…”

“…The use of lightweight aggregates in concrete, however, results in a reduction in flexural strength of the material which may limit their use in structural elements subjected to bending stresses. To improve the bending performance, Arruda Filho et al [12] used sisal fibers as reinforcement and found an increase in the flexural strength of mortar boards with EVA, indicating the potential use of plant fibers together with this light material.…”

Compatibility of vegetable fibers with Portland cement and its relationship with the physical properties

“…From the technological and environmental perspectives, the use of residues from agro-industry in civil construction has gained relevance, because it promotes technical quality, decreasing the costs of energy and natural materials for the production of constructive elements, and also avoids damages to the environment (Arruda Filho et al, 2012;Silva et al, 2014).…”