Effect of addition of Medium Steel Fibers on Dense Bituminous Macadam

Abstract

In this research paper the use of fibres emerged as a need for improving the flexibility and tensile strength of the bituminous mixes due to increase in heavy traffic density in terms of number of axles, wheel loads and high tyre pressures resulting from vehicles. Fibre-modified bituminous mixtures are generally comprised of matrix and fibres. The adhesion between fibres and matrix along with shape and size of fibres affects the performance of these mixtures. Bituminous Mixes are most commonly used all over the world in pavement construction. India has a network of over 5,897,671 kilometres (3,664,643 mi) of roads as of 31 March 2017, the second largest road network in the world. About 98 % of the paved roads in India have flexible pavements, within which are included surfacing of various types and thickness. The bituminous mix design aims to determine the proportion of bitumen, filler, fine aggregates, and coarse aggregates to produce a mix which is workable, strong, durable and economical. The horizontal stresses induced between the layers may result in easily crack formation when loads are heavy and any local settlements also lead to cracking of the asphalt layers. Pavement distresses, such as: cracking, pot-holes, permanent deformation and surface wear are constantly reported by highway agencies. Some undesirable effects can occur mainly due to high number of vehicles imposing repetitive higher axle loads on roads, environmental condition and construction errors. These usually cause permanent deformation (rutting), fatigue and low temperature cracking, service life of the road pavement is going to be decreased. Fatigue and rutting are the most common distresses in road pavement which result in the shortening of pavement life and increase maintenance cost as well as road user cost. So, it is vital to find out ways to delay the asphalt pavement deterioration and increase its service life. Many studies have been conducted to improve road pavement characteristics which can provide comfortable ride and ensure greater durability and longer service life against climate changes and traffic loading