Development of eco-efficient and cost-effective reinforced self-consolidation concretes with hybrid industrial/recycled steel fibers

This paper presents the results of an experimental/analytical investigation on the development of eco-efficient and cost-effective self-consolidation concretes reinforced with hybrid steel industrial and recycled fibers. Particularly, eleven mixtures containing different combinations of the hybrid industrial/recycled steel fibers were cast and examined under the compressive, tensile, flexural, and the repeated drop weight impact tests. Then, the mechanical properties were correlated to the resistance to impact actions. The effects of fiber combinations on the cost and the released carbon emission into the atmosphere were studied. Finally, a simplified optimization approach was used to obtain the eco-efficiency and cost-effectiveness of the fiber-reinforced self-consolidation concrete. The results showed that the greatest impact of replacing industrial steel fibers by recycled steel fibers was observed in the residual flexural strength, in ultimate impact resistance, and in the compactness. Moreover, recycled/industrial steel fiber combinations had the greater impact on increasing the cost than the released carbon emission. (C) 2018 Elsevier Ltd. All rights reserved.