قابلیت اطمینان لرزه ای ساختمانهای بتونی مسلح
Abstract
1. Introduction
2. EAF slag and its use as aggregate in structural concrete
3. RC frame code-conforming analyzed case studies
4. Theoretical background on seismic reliability analysis
5. Seismic reliability assessment of the analyzed EAF RC frame archetypes
6. Results and discussion
7. Conclusion
References
Abstract
Recent studies have demonstrated how Electric Arc Furnace (EAF) concrete represents a sustainable alternative to ordinary concretes, and that it could be satisfactorily employed to realize reinforced concrete (RC) elements. However, a comprehensive study about the effects of its use in RC structural systems, both in terms of structural safety under static and dynamic loads, and environmental impacts along the whole life cycle, has not been investigated yet. This work analyzes the seismic reliability of standard residential buildings (cast in place RC frames), considering three different configurations (3-, 6- and 9- story building type) designed considering ordinary concretes made with natural aggregates (NA) according to the novel Italian seismic code, which is similar to the Eurocode 8 approach. Non-linear time history analyses have been carried out to investigate the seismic response of the analyzed cases comparing results obtained from the benchmark structures (i.e. the NA ones) with those coming from the same made with EAF mixes, in order to verify the suitability in using sustainable EAF concrete mixes in seismic areas. Lastly, a seismic reliability analysis has been carried out for comparative purposes, demonstrating how EAF concrete overstrength compensates for the extra efforts that the analyzed RC frames may undergo during seismic events.
Introduction
Among the Sustainable Development Goals (SDG) that have been adopted by the Agenda 2030 of the United Nations [1], one of the main global challenges that the construction market has to face, together with the society, is to substantially reduce waste generation through prevention, reduction, recycling and reuse policies. In this field, the reduction of waste disposal through the promotion of recycling opportunities as construction materials has been largely a matter of study and research within the scientific world. Specifically, an extensive research has been devoted to safely use various type of waste in the construction industry, and due to the great amount of natural aggregates (NAs) consumption, this represents an important part of the market that has been explored. As indicative numbers, the European aggregates demand alone is 2.7 billion tonnes per year [2]; additionally, also for structural concrete production it is worth recalling that aggregates represent 70% in volume of a concrete mixture, in average. The most well-known case of recycling is that of Construction and Demolition Waste (C&DW), which can be used to produce Recycled Aggregates (RAs); their use is currently allowed and regulated in most of the building codes and standards around the world [3–5]. More recently, the suitability of using other kind of waste and by-products to produce so-called industrial aggregates has been object of a dynamic research, which for instance analyzed the applicability of plastic waste [6,7], recycled waste glass [8,9], recycled tires [10,11], and many other by-products, particularly from steelmaking industry [12–15].