Calcestruzzi rinforzati con fibre metalliche riciclate: studio sperimentale e modellazione teorica

MARTINELLI, E.; CAGGIANO, A.; XARGAY, H.; FOLINO, P

Milan

Congreso; 20°Congresso C.T.E.; 2014

Collegio dei Tecnici della Industrializzazione Edilizia

In the last decade, sustainability has become one of the key drivers in any human activity and industrial process. Being characterised by a significant demand of raw materials and energy, the construction sector is fully concerned by the challenge of reducing the environmental impact for preserving the limited natural resources employed for producing construction materials.As part of this widespread effort, the present paper deals with the possible use of Recycled Steel Fibers (RSFs) in the production of Fiber-Reinforced Concrete (FRC). Particularly, it investigates the mechanical behaviour of FRCs made with both industrial and recycled steel fibers, the latter being obtained from waste pneumatic tyres. Particularly, it is aimed at quantifying the expected decay in terms of post-cracking toughness induced by the substitution of increasing amounts of the former with an equal quantity of the latter. Therefore, an experimental campaign was carried out at the Laboratory of Materials testing and Structures (LMS) of the University of Salerno (Italy): specimens of four different mixtures, characterised by the same nominal amount of fibers and different relative proportions of the two kinds of fibers under consideration, were tested both in compression and four-point bending. As expected, no significant influence of fibers emerged in terms of compressive strength, whereas a significant decay of the post-cracking behaviour was observed for higher replacement ratio of RSFs. Particularly, a significant enhancement of the response in bending was generally observed with respect to reference plain concrete specimens, even in the case of all RSF replacement.Further investigations, both experimental and theoretical in nature, are encouraged by the results reported in this paper which is intended as a first contribution to pave the way towards understanding, controlling and predicting the behaviour of concrete with recycled fibers.