Laboratory Investigation of Bituminous Concrete (Grade – 1) Using Different Types of Additives

Abstract

India boasts of the third largest road network in the world. To keep up with the continuous infrastructure development, new roads are being constructed. The ever increasing population has further raised the vehicular density due to increased passenger traffic and freight transport over the last few decades. India and many other countries have more than 90 percent of roads which are constructed with flexible pavements or bituminous courses. So, to achieve the requirements, properties of asphalt binder and bituminous mixes are to be improved by using various additives. For a pavement section different types of additives are used such as Polymers, Crumb Rubber and other waste materials like waste plastic, discarded tyre tubes etc which increases the life of the pavement depending upon the degree of modification and type of additives used. Due to increase in population, the vehicular traffic density is also increasing. Due to this, the wear and tear of tyres from these vehicles is undoubted due to which large number of scrap tyres are being generated. A large number of waste and worn out tyres are already in existence and with an annual generation rate of 15-20% each year. These tyres are discarded indiscriminately or stockpiled. The used tyres had a great threat to human health and environment, since it is nonbiodegradable so it is having disposal problems also. Similarly, consumption of waste plastic is increasing day by day. More than 50% of the plastic is used as a packaging material. As plastic is a non-biodegradable waste so it does not under goes decomposition. In this, we projected to study the use of the waste tyre rubber and waste plastic as a blending material in bitumen, which is further used for road construction. If waste plastic and used tyre rubber can be added in bitumen for improving the properties of bituminous mixes. The present research focuses at developing modified bituminous mixes for Bituminous Concrete Grade 1 by partially replacing the bitumen content with waste plastic and waste tyre tube. Also the study focuses on the different blends of Bituminous Concrete Grade 1 by using Polymer Modified Bitumen (PMB) and Crumb rubber Modified Bitumen (CRMB) and Stability-Flow analysis was done with modified binders and with the replacement of waste plastic and waste tyre tubes were done. It is found that out of two materials, replacement of optimum binder content (OBC) by 8% of waste plastic and 12% of waste tyre tube was observed. The optimum binder content for Polymer Modified Bitumen (PMB) for Bituminous Concrete Grade 1 is 5.2% and for Crumb Rubber Modified Bitumen (CRMB) is 5%.