Structural reliability of bridges realized with reinforced concretes containing electric arc furnace slag aggregates

The development of sustainable concretes is becoming an emerging issue in civil construction sector. The use of recycled aggregates is one way to fulfill sustainability goals in concrete industry, and among others, the use of Electric Arc Furnace (EAF) slag aggregates has been proven to be promising in the construction of sustainable reinforced concrete structures. Past research demonstrated a significant increase of mechanical properties of EAF concretes when compared with ones made with natural aggregates (NA); however, at the same time, their use implies also an increase of self-weight loads. The present contribution aims to investigate the reliability of structural systems realized with EAF concretes, with special emphasis to bridge structures. A wide dataset of 172 experimental tests for mechanical characterization of EAF concretes is built up and subsequently used to analyze the increment in concrete compressive strength and self-weight loads for three different EAF concrete classes (i.e. C1, C2, A). Two different bridge types, considered as case-study examples, are designed considering ordinary concrete mixes, and subsequently, a reliability analysis is run for each EAF concrete class in order to investigate the variation of structural safety margins related to the use of the sustainable EAF concretes in replacement to the ordinary NA concrete mix. Results show how structural safety of the analyzed bridges built up with sustainable EAF concretes is characterized by similar levels of structural reliability, in particular evidencing higher values for EAF concrete classes C1 and C2 with respect to those computed for NA concretes