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Innovative Concrete Barriers for Forgiving Road Infrastructure

Periodic Reporting for period 1 - SAFER (Innovative Concrete Barriers for Forgiving Road Infrastructure)

Reporting period: 2017-03-01 to 2019-02-28

The project focused on the development of SAFER road barriers, made with Steel fibre reinforced Rubberised Concrete, including rubber particles and steel fibre obtained from End-of-life tyres.
The recycled tyre products, when incorporated in concrete mixtures, increase the deformability and energy absorption capacity of the material, that can reduce the effects of collision.
This research is aiming to address the issue of road fatalities in road transport, specifically aiming to reduce fatalities, in accordance with the goal set by the White Paper on Transport. With motorcyclists being the most vulnerable users, suffering from frequent fatalities in crashes involving road barriers, the European Road Assessment has indicated the critical need to adopt improved barrier designs. This research is important for society, not only because it targets the societal issue of road fatalities, but also for providing an alternative use for End-of-life tyres by using them into a high value application, contributing to the concept of circular economy. The development of SAFER road barriers was achieved by reaching the objectives of investigating the energy absorption properties of rubberised concrete reinforced with recycled tyre steel fibres under static and dynamic loading, the durability of the proposed material in regard to safety barrier performance requirements, investigating numerically the performance of rubberised concrete reinforced with recycled tyre steel fibres and developing design recommendations for steel fibre reinforced rubberised concrete barriers. The optimum Steel Fibre reinforced Rubberised Concrete mixture developed and recommended barrier designs are provided within the technical report.
The first workpackage included the review of existing literature on Rubberised Concrete and End-of-cycle tyre material recycling and the review of existing safety barrier designs. In addition to studying previous research on material properties and geometrical designs for Road Barriers, the researcher communicated with the Department of Public works, discussing shapes and sizes of existing barriers in Cyprus and also interviewed leaders of the Cyprus Motorcycle Rights Club, who visited the researcher’s office at Cyprus University of Technology (CUT) expressing their thoughts on improving the safety of existing barriers, based on personal and other club member’s experiences.

Workpackage 2 focused on both the experimental mixture development and barrier geometry designs. The mixture development process included preliminary material investigation to proceed with a mixture optimization study that produced the optimised Steel Fibre reinforced Rubberised Concrete Mixture for SAFER Road Barriers. In addition, 5 geometrical barrier designs were prepared.

The third work package included the Numerical Analysis study conducted using finite element software LS-DYNA, as well as the experimental testing rounds that were the core of the SAFER project actions, including Cube and Cylinder Compressive Strength Tests, Determination of the Modulus of Elasticity of Cylindrical Specimens, Testing rectangular Beam Specimens (Prisms) under Static Flexural Bending, and cyclic loading of Cylindrical specimens under Compression and 2 environmental durability studies, where Freezing and Thawing as well as Wet and dry Chloride Corrosion cycles were applied on rectangular prisms, assessing their susceptibility to such conditions. Finally, experimental impact performance of the optimised mixture was investigated, enabling determination of the damping characteristics of the material. Deliverable 3 is dedicated to the Numerical Analysis study and Deliverable 4 provides the all technical details regarding the experimental testing rounds conducted.

Work package 4 included the Life Cycle Assessment (LCA) of the recommended Barrier product, as recommended by the handbook of the International Reference Life Cycle Data Systems (ILCD), which conforms to the ISO 14040 and 14044 on LCA. Based on environmental impact evaluation, experimental performance of the material and numerical assessment of Barrier shapes, the recommended mixture and geometrical barrier design are delivered along with the Life Cycle Assessment results in Deliverable 5.

The SAFER project dissemination website was developed in March 2017 and social media accounts for the project were created in facebook, twitter and instagram. Information on the research project has been disseminated to the public at 2 European Researcher's Night events (2017, 2018) in Nicosia and Limassol, Cyprus with poster presentations and hands-on interaction for children and adults. The project was presented to the Tyre recycling community by 2 oral presentations at the 2017 and also the 2018 European Tyre Recycling Association Conferences, both held in Brussels, Belgium. In addition, the research project was presented to the public at the 2019 Marie Curie Alumni Association General Assembly and Annual Conference where a digital poster was orally presented.

Scientific findings have been disseminated in October 2018 at the 5th fib Conference in Melbourne Australia where a peer reviewed Conference paper was presented via an oral presentation. In March 2019, scientific findings from the project were disseminated at the 2019 RILEM Conference in Rovinj, Croatia where a peer reviewed Conference paper was presented via an oral presentation. Based on the scientific findings of the SAFER research project, 3 journal publications are under final review and will be submitted to the following scientific journals:

a) Construction and Building Materials - Paper title: “Use of End-of-life Tyre Components in Concrete: a review”
b) Cement and Concrete Research - Paper title: “Effects of Pretreatment using Waste Quarry Dust on the Surface Properties of Rubber and Compressive Strength of Rubberized Concrete”
c) Construction and Building Materials - Paper title: “Steel Fibre Reinforced Concrete with high Rubber Content aimed for Forgiving Infrastructure Applications”

All publications produced by the project are available on the project website and the university repository 'ktisis', at the link http://ktisis.cut.ac.cy/cris/project/pj00332.
Through the SAFER Project and the opportunity of this Grant, the researcher was able to achieve progress beyond the state of the art of Rubberised Concrete. Through a study on the weak interfacial transition zone of rubberised concrete and experimental work, the researcher was able to develop a simple procedure that enables enhancing the bonding action at the interface between the cement paste therefore improve the performance of rubberised concrete. The enhancement of the interfacial transition zone of rubberised concrete will enable further research on rubberised concrete and development of high added value applications that can benefit from the inclusion of End-of-life tyre materials in concrete.
The development of products that enable re-use of End-of-life tyres has a positive impact on the environment, while positive societal impact is achieved by the development of forgiving infrastructure applications such as the SAFER road barriers developed in this study, by reducing the effects of collision and fatalities in road transport.