Evaluation of the physical and mechanical properties of of sisal fibers in cementitious mortar composite

Abstract

The civil construction sector can drive the economy and attract financial resources, but environmental impacts should be considered and construction processes improved with alternative materials, such as biocomposites made from natural fibers, for example, the implementation of sisal in mortar. This work aims to evaluate the mechanical performance of sisal fibers in cementitious composite mortar. For this, fibers with lengths of 20 mm and 30 mm were used, with additions relative to the cement volume of 0.5% and 1.0%. Since there is no specific standard to characterize sisal, wood fiber standards were used instead. Statistical analysis and scanning electron microscopy (SEM) were also performed on test specimens. The following results were obtained: real specific mass and apparent specific mass of sisal were 1,440.00 kg/m³ and 525.33 kg/m³ respectively, moisture content was 5.58%, and water absorption was 150.85% in 72 hours. In the mechanical tests, the addition of 20 mm fibers at 0.5% increased the strength of the samples by 12.78% in compression and 6.84% in flexural tensile strength at early ages. In a statistical study, the homogeneity of these features was verified, and in SEM, greater cohesion was observed in samples with fibers added at 0.5% compared to those at 1%.

Keywords
Natural fibers in construction; Sisal in mortar; Increased compressive and tensile strength; Sustainability