Improving the Behaviour of Roads underlays by the Use of Industrial waste (Blast furnace slag)

The accumulation of industrial wastes stemming from the iron and steel industry has had a negative influence on the environment. The adopted procedure aimed to eliminate these undesirable wastes through recycling them by utilizing them in appropriate areas. The objective of this work is to study the mechanical behaviour of a gravel–slag mixture based on crystallized and granulated slag activated by lime. The resistance to punching and the bearing ratio of this slag are studied through Proctor, California Bearing Ratio CBR, compression, and tensile tests for use in the layers of pavement (foundation and base layers). The obtained results of the gravel–slag mixture show very good performances compared with natural aggregates with regard to the resistance and thickness of the layers. The mixture’s utilization in the road area has therefore allowed the recycling these industrial wastes, decreasing pollution, and using a minimum product requiring important energy and an economy on layers of surface realized with costly materials (bituminous concrete).