The disposal of waste tyres represents a big issue within the waste management procedures. The attempts of reusing waste tyres in many different ways is a common challenge in various branches of the modern research and technology in Europe. However, based on a recent study realised by the European Tyre Recycling Association (ETRA), a relevant fraction (nearly 23%) is still landfilled. During the last two decades, several solutions have been investigated with the aim to recycle and reuse waste tyres. One of them consists of partially replacing “natural” constituents of concrete (i.e. aggregates and fibers) with recycled ones (e.g., rubber particles in rubberised concretes and recycled steel reinforcements), in view of the twofold objectives of reducing both the demand of raw materials and the amount of waste to be disposed in landfills. Within this contest a research study is proposed herein to investigate the mechanical behaviour of concrete reinforced with recycled steel fibers recovered from waste tyres. Particularly, the results of an experimental activity carried out on Fiber-Reinforced Concrete (FRC) obtained by mixing industrial and recycled steel fibers are briefly presented. Five mixes have been considered including plain concrete as a reference and FRC with 0:5% of fiber volume fractions. The structural behaviour of FRC beams in bending has been evaluated in terms of traction-separation law and the possible synergy/substitutability of both fiber types has been investigated. A non-linear cracked hinge model is also presented through an appropriate fracture-based formulation, with the aim of simulating the crack-bridging mechanisms of steel fibers. Then, comparisons between experimental results and numerical predictions are discussed. Both the experimental analysis and the theoretical formulations proposed in this work stem out from the inter-university collaboration developed within the framework of the European Project “EnCoRe” (FP7-PEOPLE-2011-IRSES n. 295283; www.encore-fp7.unisa.it) funded by the European Union as part of the Seventh Framework Programme.
Numerical simulation of concrete beams reinforced with mixed recycled/industrial steel fibers
MARTINELLI, Enzo;CAGGIANO, ANTONIO;
2013-01-01
Abstract
The disposal of waste tyres represents a big issue within the waste management procedures. The attempts of reusing waste tyres in many different ways is a common challenge in various branches of the modern research and technology in Europe. However, based on a recent study realised by the European Tyre Recycling Association (ETRA), a relevant fraction (nearly 23%) is still landfilled. During the last two decades, several solutions have been investigated with the aim to recycle and reuse waste tyres. One of them consists of partially replacing “natural” constituents of concrete (i.e. aggregates and fibers) with recycled ones (e.g., rubber particles in rubberised concretes and recycled steel reinforcements), in view of the twofold objectives of reducing both the demand of raw materials and the amount of waste to be disposed in landfills. Within this contest a research study is proposed herein to investigate the mechanical behaviour of concrete reinforced with recycled steel fibers recovered from waste tyres. Particularly, the results of an experimental activity carried out on Fiber-Reinforced Concrete (FRC) obtained by mixing industrial and recycled steel fibers are briefly presented. Five mixes have been considered including plain concrete as a reference and FRC with 0:5% of fiber volume fractions. The structural behaviour of FRC beams in bending has been evaluated in terms of traction-separation law and the possible synergy/substitutability of both fiber types has been investigated. A non-linear cracked hinge model is also presented through an appropriate fracture-based formulation, with the aim of simulating the crack-bridging mechanisms of steel fibers. Then, comparisons between experimental results and numerical predictions are discussed. Both the experimental analysis and the theoretical formulations proposed in this work stem out from the inter-university collaboration developed within the framework of the European Project “EnCoRe” (FP7-PEOPLE-2011-IRSES n. 295283; www.encore-fp7.unisa.it) funded by the European Union as part of the Seventh Framework Programme.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
