Caracterização mecânica à flexão em placas cimentícias reforçadas com tecidos de fibras de de Malva e Juta

Abstract

The use of natural fibers as reinforcement in cementitious matrices is a renewable and lowcost alternative that generates composites with lower density and greater tenacity. Among the various fibers produced in Brazil, we can highlight the fibers of jute and mallow, produced on a large scale in the municipality of Manacapuru in the State of Amazonas and with great potential for application in composites for civil construction due to their satisfactory mechanical properties. Thus, this work refers to the bending mechanical analysis of cementitious slabs reinforced with jute and mallow fibers. Initially, kaolin was collected at km 35 of BR 174, later it was calcined at 700 ℃ for 2 hours. Afterwards, the metakaolin produced was submitted to physicochemical tests for its characterization and, finally, it was added to the cement matrix in order to reduce calcium hydroxide (Ca(OH)2). To determine its physical-mechanical properties, the cementitious matrix was subjected to tests. After optimizing the developed composite, plates were produced with partial replacement of Portland cement by metakaolin, reinforced with 3, 4 and 5 layers of fibrous fabrics treated with 2 types of treatments that were analyzed for their bending behavior. Finally, the mechanical analysis indicated that the composites molded with 4 layers of fibrous fabrics and treated with acrylic resin showed higher tenacity than the others.