Evaluation of performance of flax fiber in the SMA mix using slag as aggregate replacement

Abstract

The technology of the asphalt material and their mixtures for paving of roads was first discovered and used to large extent in the European countries and North America. The SMA (Stone Mastic Asphalt or Stone Matrix Asphalt) mixture is a gap-graded mix that is often characterized by the presence of high coarse aggregate(may be of stone or slag), fiber additives(may be natural or artificial) as stabilizers and high asphalt content. In the present research work, an attempt has been made for studying the engineering properties of the SMA mix prepared with and without fiber and using slag in partial replacement of stone aggregate for the coarse aggregate grades. The fibers used for this project is a non-conventional natural fiber, namely flax fiber and another bitumen coated synthetic cellulose fiber. This research project was done to check the suitability of flax fiber as stabilizing agent in the SMA mixture by conducting tests in laboratory in which stability and flow parameters were analyzed, also the mechanical properties of the mixture was analyzed. And slag has been used in partial replacement of the stone aggregate for all the coarse aggregate grades for preparing SMA mixes and their properties were analyzed as well. Here for the stone matrix asphalt mix the aggregate gradation is taken based on IRC-SP-79 specification and the binder content is varied as 4%, 5%, 5.5%, 6%, 7% by weight of aggregates and fiber used is at optimum fiber content i.e. at 0.3% by weight of aggregate. Here stone dust has been used as filler and binder used is 60/70 penetration grade bitumen.