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practIcal applIcatIoNs for coNstructIoN aNd the buIlt eNvIroNmeNt

Innovation & Research

Issue No. 87 IN thIs Issue

Assessment Tools CEEQUAL for Term Contracts

Acoustics Acoustic performance prediction

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Buildings Predicted & actual energy consumption 7

Construction futures Designing resilient cities

Design Designing resilient cities

Energy & Carbon Low-carbon project design

Predicted and actual consumption

Environment Low impact construction research Rainwater harvesting

Infrastructure Low-carbon project design

Reservoirs / Risk management Assessing reservoir safety risk

Safety Assessing reservoir safety risk

Structures Acoustic performance prediction Low impact construction research

Sustainability CEEQUAL for Term Contracts

Water Environment Rainwater harvesting

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3 7

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3 2 2

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6 8 also at November 2011 Seismic testing of FlexiArchTM

Masonry arch bridges are one of the oldest forms of bridge construction and have been used for thousands of years. They were originally built of stone or brick, but modern rigid arch bridges are built of reinforced concrete or steel. The introduction of these new materials allows arch bridges to be longer than previously achieved with lower rise-to- span ratios and, with reinforced concrete as the main material, can either be cast on site or manufactured as precast. However, a common problem with such bridges is cor- rosion of the reinforcement, which can lead to high repair and maintenance costs. Therefore a bridge with no or low amounts of reinforcement is a significant step change and should provide bridges with improved durability and whole life performance.


he FlexiArchTM is a patented system for the rapid construction of an

arch, based on modern precast concrete methods, which in service performs like a conventional masonry arch. The patent holder, Professor Adrian Long FREng of Queen’s University Belfast, has worked closely with Macrete Ireland Ltd for nearly 10 years on the development of the system. Two Knowledge Transfer Partnerships (KTPs) between Queen’s University and Macrete have had significant input from Professor Long, Dr Su Taylor and Dr Daniel McPolin. The method of

construction (see Figure 1) utilises precast concrete voussoirs in combination with polymeric reinforce- ment and a concrete screed so that when lifted it takes up the prescribed arch geometry under gravity forces. Thus no centering is required and construction is very rapid. The system is very sustainable as it has no corrodible rein- forcement and the flat-pack FlexiArch ele- ments can readily be stacked during storage and for transportation to site. In their current KTP, Macrete and the

Paragrid polymeric reinforcement

Insitu screed

Engineering Global Re- search Scheme Award to Dr Su Taylor at Queen’s. To date, there has been no

precast voussoirs

physical monitoring of the system under seismic load- ing. The collaboration aims to test the FlexiArch bridge sys- tem under seismic loading and to model its behaviour. It is anticipated that the ‘Flexi- Arch’ will perform at least as well as conventional masonry arches which have been in service in seismic areas of the world for centuries. This partnership will en-

Figure 1 (top): The key elements of the FlexiArch design.

Figure 2 (above): Construction of a FlexiArch Bridge.

hance the knowledge of the behaviour of FlexiArch under seismic loading and make use of advanced sensor technology for structural health monitoring. Figure 2 shows the FlexiArch rings being installed to form an arch bridge, and shows other elements of the design. The research will use intelligent data interpretation to pre- dict damage via full-scale testing at Irvine, and to es- tablish the behaviour under seismic loading to validate

predictive modelling.

University are aiming to create FlexiArch de- sign tools, and develop a range of complex- geometry FlexiArch systems for new bridges, and to strengthen existing bridges. However, the rest of this article discusses a collabora- tion with the University of California, Irvine, which is supported by a Royal Academy of

For further information about the Royal Academy of Engineering Global Research Award Scheme, please contact Angus Baker (020 7766 0606; E-mail:

For further information about the current research, please contact Professor Long (028 90974005; E-Mail: or Dr Su Taylor (028 90974010; E-mail:

Innovation & Research Focus Issue 87 november 2011 1

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