title: Use of coir pith particles in composites with Portland cement.
abstract: Brazil is the fourth largest world's producer of coconut (Cocos nucifera L.). Coconut crops generate several wastes, including, coir pith. Coir pith and short fibers are the byproducts of extracting the long fibers and account for approximately 70% of the mature coconut husk. The main use of coir pith is as an agricultural substrate. Due to its shape and small size (0.075-1.2 mm), this material can be considered as a particulate material. The aim of this study was to evaluate the use of coir pith as an aggregate in cementitious composites and to evaluate the effect of the presence of sand in the performance of these composites. Some composites were produced exclusively with coir pith particles and other composites with coir pith partially substituting the natural sand. The cementitious composites developed were tested for their physical and mechanical properties and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy to evaluate the effect of coir pith particles addition in cement paste and sand-cement-mortar. The statistical significance of the results was evaluated by one-way analysis of variance (ANOVA) test followed by multiple comparisons of the means by Tukey's test that showed that the composites with coir pith particles, with or without natural sand, had similar mechanical results, i.e., means were not statistically different at 5% significance level. There was a reduction in bulk density and an improved post-cracking behavior in the composites with coir pith particles compared to conventional mortar and to cement paste. These composites can be used for the production of lightweight, nonstructural building materials, according to the values of compressive strength (3.97-4.35 MPa) and low bulk density (0.99-1.26 g/cm(3)).
authors.affiliation: Programa de Pós-Graduação em Ciências e Engenharia de Materiais, Universidade Federal de Sergipe, Av. Marechal Rondon, S/N, 49100-000 São Cristóvão, Sergipe, Brazil; Instituto Federal de Educação, Ciência e Tecnologia de Sergipe, Av. Eng. Gentil Tavares da Motta, 1166, 49055-260 Aracaju, Sergipe, Brazil. Electronic address: giselabrasileiro@msn.com.
authors.forename: Gisela Azevedo Menezes
authors.initials: GA
authors.lastname: Brasileiro
authors.forename: Jhonatas Augusto Rocha
authors.initials: JA
authors.lastname: Vieira
authors.forename: Ledjane Silva
authors.initials: LS
authors.lastname: Barreto
mesh_terms: D000704:Analysis of Variance; D001938:Brazil; D003059:Cocos; D003252:Construction Materials; D008031:Lignin / Q000031:analogs & derivatives*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D018508:Water Purification
chemical_list: C507903:coir; D008031:Lignin
keywords: Coir pith particles; Mechanical properties; Mortar; Physical properties; Portland cement