Utilization and durability conditions of weathering resistant steel as facade panel under atmospheric conditions

The characteristics of the Weathering Steels (WS) in high strength-low alloy steels group (HSLA) and the criteria of resistance to environmental conditions are focused in this study. WS steels are frequently used in building facades, bridges, monumental designs and landscaping elements. The main aim of this study is to evaluate the material with positive and negative aspects in view of the chemical content, to develop solutions for the most aggressive environmental conditions and to lead to the concerned people about the matter to be paid attention in the applications. In this study, first of all, the development of this material is addressed in view of historical perspective and the development of its chemical content. The chemical reactions and effectiveness of alloying elements in the surface of WS, the formation mechanism of rust-patina layer and resistance to atmospheric conditions are examined in detail. The usage percentages of alloying elements for highly resistant WS to atmospheric conditions are constituted on the basis of previous and current durability tests under three environmental conditions. Especially in industrial and marina atmospheric conditions, the choice of alloying elements is very important. In the current literature, the usage of nickel instead of copper has greatly reduced the rate of corrosion, especially from the point of view of the coastal atmosphere. The choice of nickel instead of copper, which is more difficult to add as an alloying element, may provide cost reduction. In the case of the most negative atmospheric conditions and wrong detailing, countermeasures against corrosion progression on the facade are necessary. It is aimed to prevent the increase of panel replacement cost. It should not be used for long periods of moisture. In the connections of different metals, metals should be chosen as compatible which do not cause galvanic corrosion. Worldwide applications were examined with detailed solutions and environmental interactions. Depending on the atmospheric conditions, some façade and landscape applications in and around Istanbul have been examined. The present situation of the sheets used as plates and perforated panels on the facades of Piri Reis University in Tuzla district has been examined in detail by environmental parameters. The causes of formation of rust surfaces and precautions to be taken are stated. This Thesis consists of the following sections: The First Chapter presents the purpose and scope of the study. In the Second Chapter; the worldwide historical development has been evaluated as the chemical content and application variety of weathering steels. In addition, several architectural applications have been addressed. In the Third Chapter; the alloying elements in the material have been investigated in terms of their resistance to environmental conditions as types and content. In terms of different atmospheric conditions, the effectiveness of chemical elements has been compared graphically with the results of previous experimental studies. Several worldwide applications are given on the basis of façade design with different detail solutions. In the Fourth Chapter; the present applications and situations of building façades and landscapes in Istanbul and its neighborhood are evaluated regarding the atmospheric conditions together with the suggested solutions for problematic panels as well. In this context, as a typical example, the façade practice at Piri Reis University in Tuzla was examined in detail. In the Fifth Chapter; the results obtained from the topics examined in the study are listed and solution proposals are introduced. Keywords: Weathering Steel, corrosion, alloying elements, rust, patina, HSLA Steel, WS.