Community Research and Development Information Service - CORDIS

FP7

ANAGENNISI Report Summary

Project ID: 603722
Funded under: FP7-ENVIRONMENT
Country: United Kingdom

Periodic Report Summary 2 - ANAGENNISI (Innovative Reuse of All Tyre Components in Concrete)

Project Context and Objectives:
An estimated one billion tyres are discarded each year. Post-Consumer tyre arisings for EU countries exceed 3M tonnes per year. Nearly 50% of all recycled tyres/components end up as fuel, in low grade applications or in landfill. Less than 25% of the energy required to produce rubber is recovered by incineration. Tyres comprise roughly 80% rubber, reinforced with 15% steel and 5% textile fibre reinforcement. All tyre constituents (rubber, high strength steel cord and wire, high strength textile reinforcement) are high quality materials and deserve to be reused for their relevant properties.
Construction is the highest user of materials with concrete being the most popular structural material. Concrete is inherently brittle in compression (unless suitably confined) and weak in tension and, hence, it is normally reinforced with steel bars or fibres. Tyre wire, which is exceptionally strong, can be blended with other steel fibres to increase the flexural strength of concrete – saving on virgin materials and reducing energy input requirements by 97%. These fibres are also much thinner than conventional steel fibres, which means there are more in the concrete, helping to control cracks at the micro level. Applications to be examined include slabs on grade, precast concrete elements such as crush barriers, tunnels and slope stabilisation. It is anticipated that highly confined rubberised concrete can lead to highly deformable concrete elements and structures. For example, it will allow buildings and other structures to flex up to 10 per cent along their length – 50 times more than structures made from conventional concrete. Plans are now being made to use the new concrete material in seismic resistant buildings, vibration isolation and bridge bearings. As part of the Anagennisi, full scale static structural tests and shake-table dynamic tests are being undertaken to assess the potential of deformable elements and structures and to help validate numerical models. Demonstration projects are also being undertaken in several countries to convince contractors and infrastructure owners of the benefits. The textile polymer fibres in tyres, used primarily as reinforcement in passenger tyres, is also of high quality and strength and can be used to control cracking at the early stages of concrete curing, when the material is still plastic. Textiles fibres have been shown to help prevent explosive concrete spalling (crumbling, breaking up) during fires, and applications are being developed for tunnels and buildings. The aim of Anagennisi is to develop innovative solutions to reuse all tyre components in high value innovative concrete applications with reduced environmental impact. To achieve this aim, the proposed project will have to overcome scientific and technological challenges in:
• Development of novel confined rubberised concrete materials and reinforcement
• Development of high deformability RC elements suitable for integral bridge elements and base isolation systems for vibrations and seismic applications
• Development of concrete mixes using recycled steel fibres for use in various applications
• Development of concrete mixes using recycled tyre polymer fibres for crack control
• Development of novel concrete applications using combinations of the different tyre by-products
• Undertaking demonstrations projects using the developed materials/applications
• Development and implementation of standardised LCA/LCCA protocols

Project Results:
Work was conducted on FRP confined Rubberised Concrete (RuC) cylinders subjected to cyclic axial compressive loading. The results showed a very good performance and confinement worked effectively reaching stress and axial strain of 90 MPa and 6%, respectively. The durability tests (permeability, sorptivity and diffusivity) on rubberised concrete have already commenced to assess the long-term performance of rubberised concrete. FEA modelling of rubberised concrete is currently on going using existing experimental results from small scale tests. FEA modelling will be finalised, when all medium and large scale tests have been completed. The seismic performance of RC medium scale piers was assessed using AFRP confined RuC in certain regions of the piers. The results in terms of deformability and energy dissipation were very promising. Large scale RC piers have already been cast and testing will commence soon. Experimental results and analysis will be completed in period 3. A full scale building with RuC was tested in a shake table using an incremental set of seismic excitations (from 0.13g to 1.6g) focusing on short-column deficiencies. The first draft of design guidelines for applications of confined RuC for high-deformability elements was produced. The flexural performance of SFRC was investigated using specific lengths of Recycled Tyre Cord Filaments (RTCF) (6 mm to 24 mm) to assess their effect on mechanical characteristics. The results showed that all lengths enhanced the flexural capacity, however lengths above 15 mm provided more substantial enhancement. For the first time, an experimental study on the flexural properties of RuC prisms reinforced with manufactured (M) and recycled fibres (RTSF) (or their own or blended together) was conducted. The results showed that hybrid mixes (20kg/m3 M + 20kg/m3 RTSF) worked efficiently, opening the field to manufacturing flexible structural pavements. A comparative study on restrained shrinkage using prisms as well 40 m long SFRC strips, demonstrated that the degree of restraint obtained from the large scale tests was similar to the one achieved with the custom made restrained frames in the laboratory. Further work was performed on screeds using short RTCF in various dosages; The main conclusion of this study was that screed mixes containing short RTCF can be classified as self-compacting and, hence, can be used as overlays on new and damaged concrete surfaces. The behaviour of SFRC using both manufactured and recycled fibres was investigated under fatigue. It was shown that the hybrid 20M20R mix is a viable alternative (from engineering, economic and environmental aspects) solution for applications which include fatigue loadings. A revised environmental life-cycle assessment (LCA) of all concrete mixes examined experimentally in WP3 was also conducted. A small-scale cleaning device for Recycled Tyre Polymer Fibres (RTPF) was developed to successfully remove residual rubber and improve RTPF effectiveness. Self-compacting RTPF concrete mixes were promising whilst the use of RTPF in concrete mitigated spalling at high temperatures. The most efficient mix was the 40kg/m3 RTSF+5kg/m3 RTPF mix. Further durability studies showed that RTPF in concrete, resulted in a small improvement in the capillary absorption and increased significantly the freeze and thaw resistance of concrete. A 30 kg/m3 Recycled Tyre Steel Cord (RTSC) concrete mix was used to spray successfully 3 m of tunnel linings in Barcelona. The vertical and horizontal deformations of a full scale SFRC slab were monitored for more than a year and the results showed reasonable values. Shrinkage deformations stabilised 10 months after casting. Overall, 6 plenary project meetings took place as planned and these included extensive dissemination activities, industry seminars, press releases and one media training session. (More information is given in the attached PDF: Interim Report - Period 2 - FINAL - Resubmission.pdf).

Potential Impact:
The target of this proposal is to find high value uses for the constituent materials of post-consumer tyres. Rather than using the materials as cheap fillers or fuel, this proposal aims to use the rubber, steel and polymers for their intrinsic physical properties in high value concrete applications and novel solutions, including:

Development of highly deformable structural materials using rubberised concrete in highly confined conditions, for new structural elements that act as hinges, bearings, vibration and base isolation.
Development of new applications for using RTSF and Blends using RTSF, for: slabs on grade, suspended slabs, precast concrete elements, pumpable and self-compacting concrete and mortar, sprayed concrete, tough screeds.
Development of applications for using RTPF and blends using RTSF, for general use in concrete, shrinkage crack control, sprayed concrete.

The overall expected impacts include:
Reduced waste production and pressure on raw materials. Through reuse, the aim is to eliminate the amount of rubber, steel and polymer that is incinerated or ends up in landfill. Up to 50% of the potential 3,4M tonnes of tyre arisings per year in Europe could be used for structural applications, eliminating wastes going to landfill and reducing or even eliminating the amount being incinerated. Improved resource efficiency and reduced environmental impacts. The aim is to reduce the demand for raw materials such as rubber (e.g. for bearings), steel and polymer fibre reinforcement in concrete; in the EU this could be up to 1M tonnes rubber tonnes/yea), up to 200ktonnes/year of steel wire and up to 100k tonnes/year of polymer fibre. The aim is to enhance the sustainability of concrete construction by using recycled materials and less materials (due to thinner structural elements). Substantial contribution towards the sustainable supply of raw materials of economic importance in Europe through the development of a sustainable supply of reused steel and polymer fibres for concrete reinforcement and recycled rubber in bearings and base isolation systems. Work has started on the all above and a summary of the results is presented the section on Work Performed and Main Results. Improved communication and transfer of knowledge to policy making, business and to the general public is another key objective. Apart from lobbying the construction profession, tyre recycling industry and local authorities, the consortium will use the project dissemination tools to campaign for the importance of the developed technologies for future prosperity. Public understanding of science is the key for relevant policy making. Seminars had already been given at several forums of industry, professional and policy experts. LCA and LCCA studies have been initiated and these will eventually quantify the environmental and socioeconomic impacts. This work is coupled with work on design recommendations and mini trials, which have already started and some of them completed.

List of Websites:
www.anagennisi.org

Reported by

THE UNIVERSITY OF SHEFFIELD
United Kingdom
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