Recycling Building Demolition Waste as An Asphalt Binder Course in Road Pavements: A Case Study in Benghazi

Abstract

At the recent years in Libya especially in Benghazi, building demolition increase because of wars and the processes of destruction that lead to increase concrete waste, causing extreme pressure on the available land-filled sites that’s becomes a new challenge to local environment. Due to environmental reasons and the shortage of natural resources, it is greatly valuable to recycle construction and demolition waste as much as possible. This paper investigates the feasibility of using recycled concrete aggregate (RCA) as a replacement to the natural aggregates (NAs) in the Asphalt Binder Course (ABC). So this study make as first evaluation to return use concrete aggregate for old and demolition building in concrete asphalt mix In Benghazi, the recycled concrete aggregate (RCA) obtained from building to live long more than 20 years after crash reinforcement concrete and sieving to get requirement granular particle to make asphalt mixture depends on International Specification (ASTM) American Society for Testing and Materials. In this research a number of aggregate tests is conducted which are sieve analysis, specific gravity, absorption, abrasion, impact value and crushing value. These tests are to investigate the applicability of using the recycled aggregates of demolition building debris as an asphalt binder in road pavements .Also, for comparison, the same tests were applied on the natural aggregates. Furthermore, number of bitumen tests is conducted. They are penetration test, softening point and ductility. The aim was to investigate its applicability to be used as a binder material. Marshal samples are prepared using both natural blending aggregates and recycled blending aggregate to investigate the properties of the asphalt mix; flow, stability and density and comparing the results with the specifications. The results showed that it is possible to use the recycled aggregates in preparing the Asphalt Binder Course taking into account the need to increase the bitumen content, the optimum bitumen content using recycled aggregates and for natural aggregates is 7%.