Elektrik ark ocağı cürufunun yapay agrega olarak karayolu inşaatı dolgu ve granüler tabakalarında kullanılabilirliğinin incelenmesi
Investigation of the usage of electric arc furnace slag as artifical aggregate in embankment and granular layers of road constructions
Yazar: ÖZGÜR HASANÇEBİOĞLU
Danışman: YRD. DOÇ. DR. ŞÜKRÜYE İYİNAM
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Ulaştırma Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2014
Konu: İnşaat Mühendisliği = Civil Engineering

Özet:
Son yıllarda demir çelik sektöründeki katı atık malzemesi miktarının giderek artması hem işletmelere atık bertaraf etme maliyetleri açısından hem de çevresel etkileri nedeniyle önemli sorunlar oluşturmaktadır. Bu atıkların özellikle yol inşaatı gibi büyük miktarlar yapı malzemesi gerektiren üretim süreçlerinde geri kazanım yöntemi olarak kullanılması birçok ülkede yaygınlaşmıştır. 
Bu çalışmada, elektrik ark ocağı (EAO) tesislerinde hurda çelikten üretim yapım sürecinde atık madde olarak açığa çıkan EAO cürufunun karayolu inşaatı dolgu ve granüler tabakalarda kullanılabilirliği araştırılmıştır. Doğal agrega aynı çalışma sürecinden geçirilerek çıkan sonuçlar ile kıyaslama yapılmıştır. Karayolları Teknik Şartnamesi 2006 limitleri esas alınarak çalışma gerçekleştirilmiştir.
İlk bölümde, çalışmanın amacı ve kapsamı anlatılmıştır. İnşaat sektöründeki araştırma konusu olan cüruf malzemesinin kullanımının avantajları genel olarak anlatılmıştır.
2. Bölümde, karayolu inşaatı altyapı ve üstyapı tabakaları ile ilgili genel bilgiler verilmiştir. 
3. Bölümde, Karayolları Teknik Şartnamesi 2006'ya göre dolgu ve granüler tabakalardaki (alttemel, temel ve plent-miks temel) agreganın fiziksel özellikleri ile tabakalar için şartnamenin öngördüğü CBR (Kaliforniya taşıma oranı ), Proktor (Standart/Modifiye) gibi, tabakalara uygulunan deneylerin limit değerleri tablolar halinde gösterilmiştir. Bu malzemelerin uygulamadaki kullanım şartları genel olarak anlatılmıştır.
4. Bölümde, demir çelik üretim tesisleri ve bu tesislerin üretim işlemleri hakkında bilgiler verilmiştir. Dünya'da ve Türkiye'deki çelik üretimi hakkında genel bilgiler tablolar halinde gösterilerek, EAO tesislerinin ülkemizdeki demir çelik sektöründeki önemi vurgulanmıştır.
5. Bölümde, demir çelik üretiminde atık madde olarak açığa çıkan cüruf malzemesinin oluşumu ve cüruf  malzemesinin uluslararası kullanım alanları belirtilmiştir.
6. Bölümde, EAO cürufu ve doğal agreganın fiziksel özelliklerini belirlemek için yaplan elek analizi, özgül ağırlık ve su emme, Los Angeles aşınma, yassılık indeksi, organik madde içeriği, kırılmışlık oranı, kil topakları ve dağılabilen tane oranı deneyleri, agregaların hava etkilerine karşı dayanıklılık (donma), gevşek birim hacim ağırlık, likit limit ve plastik limit deneyleri olmak üzere standart agrega deneyleri ve tabakalara (Dolgu, Alt Temel A, Alt Temel B, Temel Tip-A, Temel Tip-B, Temel Tip-C, PMT Tip-1 ve PMT Tip-2) uygulanan Proktor ve buna bağlı yaş CBR deneyleri için gerekli malzeme ve yöntemler anlatılmıştır.
7. Bölümde, tüm deneylerin sonuçları tablolar halinde gösterilmiş, EAO cürufu, doğal agrega ve KTŞ 2006 limit değerleri karşılaştırılmıştır.
8. Bölümde, yapılan deneysel çalışmalar sonucunda elde edilen sonuçlara göre değerlendirmeler yapılmıştır. EAO cürufunun karayolları dolgu ve granüler tabakalarda kullanılabilirliği için gerekli şartname koşullarını sağlama durumu irdelenmiştir.

Abstract:
The need to preserve diminishing natural resources and increase reuse, recycling or reprocessing, with disposal being the last resort has become an issue of great importance in our modern society. In the recent years, waste disposal has substantially increased in steel and iron sector. This significant increase has become major problem for the iron and steel production companies in the matter of providing solid waste storage area. Therefore the usage of steel slag has become widespread as construction material in road constructions of many countries.
Road construction is an activity in which natural resources are utilized the most in comparison with other branches of civil engineering. Large quantities of natural materials, gravel, rocks and sand are built into kilometres of newly-built roads or in reconstruction of decrepit roads. At the same time, the sustainable development concept requires a more efficient management of waste materials and preservation of environment. 
Electric arc furnace slag is the main by-product in metallurgical industires. Electric arc furnace slag is produced during the manufacture of crude steel by the electric arc furnace (EAF) process. In this process steel scrap with additions of fluxes (e.g., lime and/or dolomite) are heated to a liquid state by means of an electric current. During the melting process the fluxes combine with non-metallic scrap components and steel incompatible elements to form the liquid slag. As the slag has a lower density than steel, it floats on top of the molten bath of steel. The liquid slag is tapped at temperatures around 1600 °C .The resulting large quantities of EAF slags produced and their potential impact on the environment have prompted material scientists and civil engineers to explore the technically, cost-effective and enviromentally acceptable use of slags in highway construction.
This study presents the basic characteristics of electric arc furnace slag which is generated as waste material and the possibilities of the application of slag  in embankments and granular layers of highway construction in Turkey. 
In this study, EAF slag generated from an electric arc furnace in Izmir and natural aggregate produced from quarry in Istanbul have been investigated together. Routine laboratary tests have been performed on the materials to determine the basic and mechanical properties. The results of laboratary tests  have been compared for both material and these experimental values have been evaluated according to the limit values of Republic of Turkey Technical Specification of Highways 2006. All values have been shown in the tables in order to determine the availability of utilization of EAF slag in granular layers of road constructions.
In the first section of thesis, the study has begun with a review of steel slag wastes and the purpose and scope of the study has been emphasised in this section.
In the second section, the general information has been given for the subgrade, granular layers (subbase, base ) and pavement types ( flexible, rigid and composite) of highways. The basic functions of the parts of highways have been described in this section.
In the third section,  the physical and mechanical  properties of aggregates have been described and demonstrated in tables according to requirements of Technical Specification of Highways 2006. In order to use EAF slag material in highway constructions in Turkey, it has to meet the requirements which have been described in this section. These requirements have been stated as limit values for the material utilized in road constructions. The results of laboratory tests which have been performed in the scope of this study have been compared with these limit values in the next sections. Additionally, the implementation conditions of the material to be utilized in road constructions have been stated in generally. 
In the fourth section, iron and steel production process has been explained in detail. The types of plants have been mentioned as blast furnace, basic oxygen furnace and electric arc furnace  within this section.The general information has been given about the steel production of Turkey and other countries. In additon to this subjects, significance of electric arc furnace has been underlined for steel production in Turkey.
In the fifth section, generation of steel slag has been described in detail. Three types of slag which are called as blast furnace slag, basic oxygen furnace slag and electric arc furnace slag has been given in this section. Different types of properties of slags arising from steel production processes, furnace types, cooling properties and the aging processes have been explained. The other information  has been explained that iron and steel slag has been also used as a material in various sectors owing to many years of research. The international applications for iron and steel slag  have been shown in tables.
In the sixth section, in order to determine physical and mechanical properties of EAF slag and natural aggregate,  routine laboratary tests have been performed on the materials and also the granular layer tests have been carried out to find out the properties of metarials' behaviour  in granular layers. In this section, sieve analysis test, density and absorption of aggregate test, Los Angeles abrasion and impact test, elongation index test, determination of organic matter test, clay lumps and friable particles in aggregates test, soundness of aggregates by use of Sodium Sulfate or Magnesium Sulfate test, bulk density ( "unit weight") and voids in aggregate test and liquid limit, plastic limit and plasticity index of soils test have been explained  how performed for EAF slag and natural aggregate in order to determine physical properties of materials. Additionally, the granular layer tests which are Standart and Modified Proctor, CBR (California Bearing Ratio) test and potential expansion of aggregates from hydration reactions test have been explained in this section. These tests have been implemented with respect to standards referred in the Republic of Turkey Technical Specification of Highways 2006.
In the seventh section, the experimental values have been pointed out explicitly. EAF slag has been examined whether they could be used in granular layers instead of natural aggregate comparing with each other's test results and limit values of technical specification.  
In the last section, EAF slag has been evaluated in the light of physical and mechanical properties regarding usability in fill and granular layers of highways instead of natural aggregates. In brief,  EAF slag has met the required specifications of current standards as fill material and granular layers of highways. Good interlock between EAF slag aggregate particles provides good load transfer to weaker subgrades because of their similar particle shape and angle of internal friction. The physical and mechanical properties of EAF slag aggregate make it a suitable material for road construction where it can be used from fill layers to the granular layers.