Compósitos à base de cimento reforçados com fibras de celulose

Abstract

Demand for the use of ecologically sustainable and affordable materials it is the current intention in all areas of the world, specifically in civil construction. The purpose of this work is to investigate the feasibility of using cane cellulosic fiber in composites at cement base as an alternative in forming blocks. Cellulosic fibers were extracted from the reed by the Kraft method. In the formulation of the mortar, the fiber content was varied by 0, 15, 20 and 25% by weight of cement. 14 specimens were molded to analyze the compression load (6 cuvettes) and those inherent to the material's resilience (8 prisms). The specimens were cured by 28 days of age and then the predefined tests were performed. Thermal stability was also determined based on the thermogravimetric analysis. The results indicated that all composites absorbed water, however, proportionally to the incorporated fiber content. The flexural strength was 0, 40, 0.34, 0.30 and 0.23 MPa for the proportions of 0, 15, 20 and 25% of fibers, respectively, which indicates that the optimum fiber content stood at around 15%. The results of compressive strength were decreasing with the increased fiber content, 4.41; 0.87; 0.69 and 0.31 MPa. The use of reed cellulosic fiber for the reinforcement of mechanical properties of composites cement base as an alternative in the manufacture of blocks was not viable, because the NBR standard 6136 (1994) requires that the simple compressive strength be greater than 4.5 MPa after 28 days, for the mortar to be used for block production. Keyword: Cellulosic fibers, Mortars, Portland cement.