STUDY ON SELECTED WASTE MATERIALS FOR LOW COST ROADS

Abstract

Low cost roads are those roads which are constructed using cheaper material with low cost construction techniques. The cost of roads construction can be considerably reduced by selecting local materials for the construction of the lower layers of the pavement such as sub-base courses. If the local soil is not suitable for supporting wheel loads, then the properties are improved by soil stabilization techniques. Thus stabilization techniques should be adopted for the construction of low cost roads. Substantial quantity of waste materials are available in our country. There are many waste materials like flyash, blast furnace slag, rice husk, bagasse etc., which can be converted into meaningful wealth as an alternative road binding materials. Over 40 MT of flyash is generated per year in 70 thermal plants across the country. The expected level of production of flyash by 2000 A.D. will be around 120 million tonnes. About 28,300 hectares of storage land would be required for disposal of such a huge quantity of flyash. A number of agro wastes can also be effectively used in road construction. Rice husk is one , of them and it is available as an waste from paddy mills. The annual production of paddy during 1992-93 was estimated to be around 112 million tonnes. Theoriatically, it will be able to produce 7.4 million tonnes of rice husk ash per year. The main advantage with the use of rice husk ash is that it is available throughout the country, particularly at rural road site, almost free of cost, while flaysh is available at the power houses only..