Effect of Rice Husk Ash and Steel Fibre on the Strength Characteristics of Pavement Quality Concrete

Abstract

The world’s second largest road network of almost 3.5 million Km consisting of both paved and unpaved surfaces is in India. Roads in India are presently constructed not with the right choice of material. Bitumen and concrete are the two major types of materials used in road construction in the country. Construction of concrete roads in the country is of very small share. There is growing interest in the construction of concrete pavements, due to its high strength, durability, better serviceability and overall economy in the long run. The thrust nowadays is to produce thinner and green pavement sections of better quality, which can carry the heavy loads. The high strength steel fibre reinforced concrete is a concrete having compressive strength greater than 40MPa, made of hydraulic cements and containing fine and coarse aggregates; and discontinuous, unconnected, randomly distributed steel fibres. The present study aims at, developing pavement quality concrete mixtures incorporating waste Rice Husk Ash as partial replacement of Cement as well as addition of steelfibres by volume of concrete. The aim is to design of slab thickness of PQC pavement using the achieved flexure strength of the concrete mixture for different percentage of steel fibres and replacement of cement with Rice Husk Ash and are reported. It is found out the maximum increase in flexure strength and compressive strength is for 10% waste Rice Husk Ash and 1.5% Steel fibre. Due to this increase in the flexural strength it is possible to achieve a saving in cost of Pavement Quality Concrete construction. In this study it has been observed that with 10% replacement of cement with Rice Husk Ash and addition of 1.5% steel fibres, the maximum saving 2.04% in cost per kilometre has been achieved for the 8.5m wide PQC carriage by calculating the thickness required for the PQC slab as per IRC: 58-2002.