Study on utilization of building debris in road construction in northern province of Sri Lanka

Abstract

Due to rapid development and population growth, construction industry has emerged with few new problems. The major problem faced by the industry is the scarcity of construction material and disposal of construction waste because of high disposal cost and inadequate land fill area. Northern region of Sri Lanka is undergoing a massive infrastructure development within a shorter period especially in the road sector development. Roads are major consumers of aggregate and soil and the influence of aggregate cost is more in total construction cost of the roads. The aggregates for these road construction projects are transported from Medawachchiya due to scarcity of local material and the approximated transport distance from Medawachchiya is more than 150 km. Hence, transport cost is approximately 70% of the project cost. In order to curtail the cost of construction of roads and reduce the industrial waste disposal, the possibility of using building waste as road construction material has been studied. Building debris such as concrete, random rubble masonry, concrete block and plaster were selected for this research. Experimental studies were carried out to determine the engineering properties of the recycled construction material and compared with conventional road construction material. Aggregate Impact Value Test, Aggregate Crushing Value Test, Los Angeles Abrasion Test and California Bearing Ratio Test were carried on selected building debris to find out the suitability for road base construction. Crushed samples of selected debris were tested to determine the suitability for replacement of soil in road construction. It has been observed that the Random Rubble Masonry debris can be directly used for road base construction however, crushed debris of block masonry, plaster and concrete can replace the soil for construction of sub base, shoulder, embankment and for surface of ‘D’ & ‘E’ class roads after adding suitable percentage of plastic clay.