CPD Specifier May 2015 issue January 2015 | Page 49

Structural Repair

Structural Concrete Alliance
announces award winners
The 2014 Structural Concrete Award identified
innovative structural concrete repair and
refurbishment solutions which overcame the
most demanding of engineering challenges,
while advancing technology and understanding
in this specialist field.
Entries were received from members of the
three trade associations which make up the
Structural Concrete Alliance. Members of the
Concrete Repair Association (CRA), Corrosion
Prevention Association (CPA) and the Sprayed
Concrete Association (SCA) supplied details of
the solutions they had delivered to overcome
difficulties encountered in a range of demanding
projects.
The judging panel was impressed by the high
standards of the entries, which served to
highlight the professionalism of CRA, CPA and
SCA members.
THE WINNER
The award was presented to Mott Macdonald
for its refurbishment of Ryde Pier on the
Isle of Wight, completed in April 2013. The
judging panel felt that the innovative approach
implemented best respresented the expertise of
the asset protection and repair industry.
The contractors overcame access challenges
related to working in a tidal environment,
within a site of special scientific interest, while
keeping the pier and its railway line open to the
public throughout the works. By introducing the
use of marine anodes fixed to the sea bed to
protect both the steel structure of the pier and
the concrete, Mott Macdonald demonstrated
an innovative use of technology, resulting in
substantial savings in time, materials, disruption
and costs.
Ryde Pier was built in 1877, to serve ferries
to the mainland. A railway line runs long the
pier to a ferry passenger terminal. In 2009,
Mott Macdonald produced an outline repair
specification for the pier which involved two
cathodic protection (CP) systems. One was to
protect the concrete elements, installed on the
concrete surface, while the other protected the
submerged iron and steelwork, using anodes
submerged in the sea.
In 2012, the project went out to tender and Mott
Macdonald were approached by specialist repair
contractors Volkerlaser to undertake the detailed
design.
For the concrete system, the design required
work down to 1m below mean tide level. This
would have involved cutting chases into the
concrete, installing anodes and grouting them
in place, which would have been difficult due to
the tide.

STRUCTURAL CONCRETE ALLIANCE

For protection of steelwork in a marine
environment, submerged anodes fixed to the
sea bed use the sea to protect submerged
steel up to mid tide level. Mott Macdonald
and Volkerlaser proposed using the same
techniques to protect the concrete, an approach
that had never been taken before.
After undertaking thorough testing and analysis
Mott Macdonald confirmed that the plan would
not only provide protection for the steel in
concrete but also extend this protection to 1m
above sea level. As a r