Investigation of the effects of ferrochrom slag aggregate on performance of permeable bituminous mixtures

Recently, researches on recycle of industrial wastes have increased due to the conservation of natural resources and environmental worries. The construction sector, especially the road structures enable the recycling of high amounts of waste materials. Porous asphalt pavements are applied to increase the functional performance of road pavement and driving safety in areas with high rainfall. Coarse aggregate is used in a large extent in porous asphalt mixtures to ensure the void ratio. Due to the contact between the coarse aggregates, the strength and the adherence of the bituminous binder of the aggregate used in these mixtures should have a good level. In this study, which investigates for the usability of ferrochrome slag in the porous asphalt mixture, three different gradations of Type-2, Type-3, Type-4 that are specified for the permeable asphalt mixtures in the highways, technical specifications are selected and the design criteria of the mixture prepared with ferrochrome slag is examined. Mixtures are prepared to use a uniform polymer bituminous binder (PMB 76-16). Design experiments performed on specimens, are prepared in different bitumen percentage, such as volume analysis, permeability, Cantabro abrasion loss, indirect tensile strength and resistance to moisture damage. Experimental results, the void and permeability values of Type-2 mixtures were significantly below the minimum limit values, while the best hydraulic permeability level was obtained from Type-3 blends. The optimum bitumen ratios of Type-3 and Type-4 blends, which are close together in the design test results, Type-3 is determined to be %6,50 when Type-4 is 6,00. Compared to the design results with ferrochrome slag and limestone aggregate, it was determined that ferrochrome slag improves the design criteria of porous asphalt mixtures depending on its physical properties and it could be used as aggregate in permeable asphalt pavements.