Laboratory performance evaluation of environmentally sustainable sisal fibre reinforced bituminous mixes

- This study investigated the effect of sisal fibre on performance of bituminous mix.
- Laboratory tests were conducted on mixes with 4 different fibre lengths and dosages.
- Optimum results were obtained for 15 mm fibres at 0.05% dosage by weight of aggregate.

Sisal fibre is a natural fibre, which runs along the length of sisal leaves, extraction of which yields fibre. These fibres, which are spared from decomposition, may find significant application in pavement engineering. In this study, an attempt has been made to evaluate the application of sisal fibres in improving the behaviour of bituminous mixes. The effects of addition of four different lengths (5, 10, 15 and 20 mm) with four different dosages (0.05, 0.1, 0.2 and 0.3% by weight of aggregate) on stability, flow and air voids in the bituminous concrete mixes were investigated. The optimum bitumen content was obtained for different combinations. To arrive at the optimal dosage of fibre and length, laboratory performance tests such as stiffness modulus, fatigue life and moisture sensitivity were carried out for all the combinations. The fibre length of 15 mm at 0.05% dosage by weight of aggregate with an optimum bitumen content of 5.4% by weight of mix was seen to provide better performance.

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