Slurry infiltrated shredded fibre reinforced concrete (SiScon) for precast applications: Fid-Bau Portal

Slurry infiltrated shredded fibre reinforced concrete (SiScon) for precast applications

Tlemat, H. / Pilakoutas, K. / Neocleous, K.

The recent European Union ban on disposing used tyres to landfills has highlighted the need to increase the recycling rates of used tyres. The most environmentally friendly solution is to reduce tyres to their physical and chemical constituents (such as rubber, carbohydrates, carbon, and steel). To achieve high recycling rates, it is necessary to develop market areas, which will consume the tyre by-products. The recycled steel is obtained in the form of fibres. Recent research has shown that these steel fibres can be used to reinforce concrete elements. It is estimated that 400,000 tonnes of high quality steel fibres could be recovered annually from used tyres in the EU alone. An experimental study of slurry infiltrated concrete slabs reinforced with tyre-recycled steel fibres is presented. For comparison purposes, steel-fibre-reinforced-concrete slabs and conventionally reinforced concrete are also examined. It addition, the flexural characteristics of each slab are examined by performing compression and bending tests. The experiments demonstrated that steel fibres from recycled tyres can be successfully used to reinforce structural elements. The extend of reinforcement depends on the amount of fibre that can be mixed with the concrete. The behaviour of the Rcon slab was worse than expected due to the punching shear mode of failure, which can only be prevented by shear reinforcement (or fibre reinforcement). The Scon slab behaved very well considering the small amount of fibres included. Clearly if a high amount of fibres can be mixed (without balling), an even better behaviour can be expected. The Peon slab also behaved well, but few fibres penetrated in between the holes reducing the overall capacity. The best behaviour was achieved by the SIScon slab, which exhibited a high load and durability, even higher than the Rcon. This is despite the fact that the fibre used was contaminated with rubber. The SIScon slab satisfies well the BS-EN-124 loading condition of C250, while the Rcon slab just satisfies that class. The Peon slab satisfies the B125 class. Due to the low value of the point of proportionality in FSIScon beam, the equivalent flexural toughness is lower than in FPcon beam. It is anticipated that the use of recycled steel fibres in SIFCON applications will not just reduce the use of industrially-produced steel fibres and the dissipation of energy, but also cut the cost by more labour and time needed for using conversional reinforcement. The results indicate that the slurry infiltrated slab exhibit a high load and ductility, even higher than that of the conventional reinforced concrete. In addition, the tested slab satisfies the C250 loading condition of BS-EN-124.