Investigation of usage of electric arc furnace slag as aggregate in wearing course and in binder course of flexible pavements

After the industrial revolution, there are so many development in the world. Increase in population and technological developments has caused speed up and that has made way for consumption growth and resource shortage. This consumption growth has drived people to destroy the nature to satisfy the needs of consumption. Development in numerous fields has caused the environmental values to be neglected in many times. At first, these environmental issues were discounted by people and governments. People just want to come up in the world, increase the quality of their life without considering about the future. They were using up all the facilites, all the natural resources to enhence their quality of life. But, nowadays, these issues are the most important problems for people and governments. Nowadays, this is not a problem for a region, this is a problem for all world. That is why there are so many researches about the environmental pollution or recycling methods in these days. People are more conscious than the past. People care about the environment because they all have learnt the natural resources are not endless. There are so much consumption in construction industry. Recycling in construction industry is the necessity for the nature. Concrete, asphalt, iron-steel are the mostly consumpted materials in construciton industry. These materials have got an important percentage in recycling operations. The materials which are used in asphalt plank wearing surface mostly consists of agregates. Aggregates are the 95 percent of these materials. The stone pits around the construciton area are the fund for these aggregates. When these stone pits drain away, there is a need of another drain pits and for this reason earth surface has damaged day by day. Agregates which are the main material of asphalt plank wearing surface has a big percentage of a pavement design. There must be different properties of aggregates for each layer of the pavement. The wearing course is the most important layer for the road safety. The aggregates which are used for wearing course must have a high coefficient of friction and they must have a high polishing strength. In order to do that the aggregates which are used for wearing course must has good mechanical properties. To supply aggregates which have good mechanical properties is too hard in these days. There are some new regulations for stone pits and it is harder than past to build a stone pit and to manage it. Also there is another problem which is wasting stone pits around the construction sites. The construciton firms go towards another stone pits which are a long way off from the construction sites. This situation causes increasing of the manifacturing costs. Increasing of the amount of the slag with the increasing of the industrialization can help decreasing manifacturing costs and environmental pollution with being used in road construciton. In this study, the usage of electric arc furnace slag as aggregate in wearing course and binder course of flexible pavements was searched and compared with natural aggregate. The electric arc furnace slags are supplied from Ekinciler Demir ve Çelik Sanayi A.Ş. in Iskenderun, the natural aggregates are supplied from Omerli-Alyans stone pit in this study. In the first section of this study, there is a briefing about purpose of the thesis and scope of the thesis. The second part of this thesis is about flexible pavement and the courses of these flexible pavements. The next section of the study, a general information about the materials which are used in each courses of flexible pavements and these materials' properties were given. In additon, the spefication infromations were given in this chapter. In the fourth chapter of the thesis, a general infromation about the iron-steel sector has been given. The place and importance of iron-steel in our country and also in the world were given with numeric datas. In addition to that, there is some information about the production of the iron-steel and its production methods. In the fifth chapter of the study, some information about the slag which is called a waste material in iron-steel sector were given. Also there are some information about the chemical and physical properties of these slags. Finally, the areas of usage of these slags were given in this chapter. In the sixth part of the study, laboratory studies of the electric arc furnace slag and natural aggregate were given. The materials which are used in labratory, the tests which were done, and the methods have been given in this chapter. There is some information about the tests which help for identification of the physical and mechanical properties of the slag and natural aggregetas. These tests are sieve analysis, specific bulk density and water absorbtion experiment, abrasion (Los Angles) experiment, flatness index test, peel strength test, consisting of organic matter experiment, polishing test. Also there are two bitumen experiments which are specific bulk density and penetration test. After these tests, test phases of Marshall experiment and calculation methods are described. In the seventh part of the study, results of the aggregate tests, bitümen and marshall experiment which were described in sixth chapter, were given. In this part, given some graph and calculate about natural aggregate and electic ark furnace slag. Useage of electic ark furnace slag and natural aggregate's graph, find optimum bitumen for each of them. And compare electric ark furnace slag's graph and natural aggregate's graph. The optimum percentage of bitumen of asphalt mixture was determined by Marshall Stability tests using bitumen content of %4,0, %4,5, %5,0, %5,5, %6,0. All the experimantal studies are conducted as per Republic of Turkey General Directorate of Highways Technical Specification. Addition to that, the comparison of the results with the spesification limits has been given in this chapter. Charts and graphics with optimum percentage of bitumen of asphalt mixture help for determining of the physical and mechanical properties of slags and natural aggregates. In the last section of this study as conclusion, there are some evaluation about the usage of electric arc furnace slag as aggregate in wearing course and binder course of flexible pavements. Additionally, there are some suggestions according to evaluations of the results of the all study.