Characteristics of stone matrix asphalt by using natural fibers as additives

The increased growth of traffic and maintenance expenditures demands a great need for developing better, long-lasting, and more efficient roads that prevents or minimizing bituminous pavement distresses. The Stone Matrix Asphalt (SMA) mixtures provide a durable wearing course in the flexible pavements. This research is to study the influence of additives on the characteristics of SMA mixtures and to propose an ideal surface course for the pavements. The additives used for this investigation are natural fibres such as coir, sisal and banana fibres. A preliminary investigation is conducted to characterize the materials used in this study. Marshall Test and Indirect tensile strength tests are conducted for optimizing the SMA mixtures and to study the engineering properties of stabilized mixtures respectively. Based on the volumetric and mechanical characteristics of the various stabilized mixtures it is inferred that the optimum fibre content is 0.3% fibre by weight of mixture for all fibre mixtures irrespective of the type of fibre. But in all stabilized mixtures, the volumetric results are within the specification range. The coir fibre is the best among the fibres that are used in the investigation where as Sisal and banana fibre mixtures shows the same characteristics on stabilization. The present study is carried out to provide a brief understanding of the engineering behavior of the SMA mixture with various natural fibres as additives, which increases the level of confidence in the field application of this material.