Evaluation of strength characteristics of fibre reinforced concrete: A case study of glass and sisal fibres

Abstract
The strong performance of fibre reinforced concrete with the stepped introduction of glass and sisal fibre was evaluated. In this study, fibres as light reinforcements with varying percentages of 0, 0.25, 0.50, 0.75, 1.00, 1.25 and 1.5 by weight of concrete were added to M15 grade concrete. The water/cement mix proportions ratio was 0.6. Control specimens, such as cubes were cast and tested at 7, 14, 21 and 28 days respectively to determine the mechanical properties. Glass fibre resulted in the most workable mix as compared to the sisal fibre with the highest slump and compaction factor of 19.50 mm and 0.93 respectively on the addition of 0.25% fibre. The addition of glass and sisal fibres in plain concrete (control) up to 1% increases the strength of concrete while the addition of fibres content greater than 1% resulted in a reduction in the strength of concrete. The optimum glass and sisal fibre content was 1% with maximum compressive strength of 36.50 N/mm2 and 34.67 N/mm2 at 28 days respectively. The experimental study revealed that glass fibre was stronger than sisal fibre. Hence, the fibre content of 1% is recommended for use as light reinforcement in concrete.