Efeito da adição de fibras da palma do licuri (syagrus coronata) no comportamento físico e mecânico de compósitos de matriz cimentícia

摘要

This research was motivated by the requirement of asbestos s replacement inbuilding systems and the need to generate jobs and income in the country side of thestate of Bahia, Brazil. The project aimed at using fibers from licuri leaves (syagruscoronata), an abundant palm in the region, to produce composites appropriate for thesustainable production of cement fibre reinforced products in small plants. Thecomposites were produced in laboratory using Portland cement CP-II-F32, sand,water, licuri palm fiber contents of 1.0, 1.5 and 2.0% by weight of binder (two differentfiber length) and metakaolin. The latter was chosen as an additional binder for itsefficiency to reduce the alkalinity of cementitious matrixes therefore preventing thedegradation of vegetable fibers. The characterization of the composite componentswas carried out by sieving and laser particle size analyses, thermal analysis,fluorescence and X-ray diffraction. The composites performance was evaluated by 3-point-bending tests, compressive strength, ultrasound module of elasticity, free andrestrained shrinkage, water capillarity absorption and apparent specific gravity. It hasbeen found that the addition of fibers increased the time to onset of cracking over200.00% and a 25% reduction in cracks opening in the restrained shrinkage test. Thecapillary absorption reduced about 25% when compared to fiber-free composites. Itwas also observed with regard to flexural strength, compressive strength and specificgravity, that the addiction of fibers did not affect the composite performancepresenting similar results for compounds with and without fibers. In general it can bestated that the reinforced composite fibers of palm licuri presents physical andmechanical characteristics which enable them to be used in the intended proposalsof this research