Calibration of predictive formulations and key mechanical properties of reclaimed structural steel

Steel reuse is recently emerging as a necessary alternative not only to demolition and waste disposal, but also to new steel to provide circular and low-carbon stock of structural members for steel constructions. This work examines the structural behavior of reclaimed steel members with a view to support Eurocode-compliant design for steel reuse. A dataset of 182 members recovered from UK buildings was assembled, including tensile tests, Vickers hardness measurements, Charpy impact tests, and chemical composition analyses. The dataset was sorted by grading schemes consistent with CEN/TS 1090–201 and SCI P427 and included grades from S235 to S460. Correlations between Vickers hardness and both yield and ultimate tensile strength were derived specifically for reclaimed material and compared with existing formulations from literature and current reuse guidelines. The grading outcomes for the various formulations were assessed. The same dataset was then used to calibrate partial safety factors for material strength following the design-assisted-by-testing procedure in EN 1990. For S275 and S355 steel graded under the herein-called “restricted” scheme, the calibrated partial factors for yielding and ultimate strengths are close to the current values adopted for new steel in EN 1993-1-1. The results suggest that reclaimed members which satisfy current grading and testing requirements can be designed with material safety factors comparable to those of new production, while making greater use of non-destructive hardness testing to reduce the need for destructive tests in practice.