Issue 5 – December 2015

The Structural Concrete Alliance has announced the winner of the 2015 Structural Concrete Alliance Award for Repair and Refurbishment as Concrete Repair Association member Bersche-Rolt for its concrete repair and coating works to the Barry Island Eastern Shelter in September 2014.

The award was presented to the company by broadcaster Huw Edwards during the Concrete Society Awards held at the Grosvenor Hotel, Park Lane, London on 4 November 2015.

Bersche-Rolt Ltd completed concrete repair and coating works to the Grade II listed Barry Island Eastern Shelter, as part of a significant regeneration of the Eastern promenade for Vale of Glamorgan Council.

The reinforced concrete structure, constructed in the 1930s, has a concrete roof slab supported by columns on the seaward side, a retaining wall on the landward side and a series of primary and secondary concrete beams. All structural elements showed signs of concrete defects, with cracking and delamination within the beams and columns, reinforcement corrosion and peeling and discoloured paintwork.

Working closely with consultant engineers, Bingham Hall Partnership, Bersche-Rolt first carried out a survey of the structure before preparing a specification for the repairs, using products from Sika. Works included cleaning and priming the reinforcement, the application of a bonding bridge, erecting shuttering and repairing the concrete. The complete structure was then coated with a three-part protective anti-carbonation system in a decorative coloured finish.

Commenting on the award, the judges stated:

“The Alliance judging committee agreed this was the winning project given the professional and sympathetic approach to restore and enhance the structure to extend its service life within the landscape on Barry Island.”

“The main aim of the initiative was to create a scheme of urban realm improvements which would create a contextual improvement to this part of Barry Island and act as a catalyst for further private sector investment.

“The Eastern Shelter, now fully restored, sits proudly within the surrounding landscape and on Barry Island’s rejuvenated Eastern Promenade.”

Second place was awarded to Sika Ltd for its solution for Britannia House, a 1930s building with a concrete-encased steel frame in the heart of Bradford city centre.

Balfour Beatty Concrete Repairs was awarded third place for its repairs to the Sherborne Footbridge in Salford.

The winners were chosen from entries received from members of the three trade associations which make up the Structural Concrete Alliance: the Concrete Repair Association (CRA); Corrosion Prevention Association (CPA); and the Sprayed Concrete Association (SCA).

Corrosion Control Services Limited has undertaken repairs to the existing cathodic protection monitoring system installed on the A82 Borlum Bridge at Drumnadrochit in the Highlands of Scotland.

The A82 Borlum Bridge is situated to the south of Loch Ness and carries the road over the River Coiltie. The existing ICCP system had been previously switched off to allow access steps to be built but never re-connected.

The contract, awarded by BearScotland, was to carry out initial re-energising of the system to confirm compliance with the standards. CCSL undertook testing with a portable power supply and showed that the ICCP system polarised and satisfied the performance monitoring criteria.

CCSL engaged the services of ForceTechnology/CPI of Denmark to manufacture new monitoring equipment. The durAdjust 485 system was offered as the best solution and, following a factory visit to Copenhagen, the equipment was accepted for use in the works.

The new monitoring system was installed and repairs to the cable infrastructure were undertaken to prevent damage, since the DC monitoring cables were lying on the river bank.

The ICCP system was successfully re-commissioned and will be monitored for a period of 52 weeks by CCSL.

VolkerLaser has been selected as a finalist in the Project of the Year (subcontract over £2m) category of the 2016 Construction News Specialists Awards, making the shortlist from among a record number of entrants.

The project was the refurbishment and strengthening of the Woodhouse Tunnel which carries the A58(M) beneath Leeds city centre, Leeds General Infirmary, as well as adjacent to the university. As a major artery within the centre of Leeds it sees over 75,000 cars pass through every day.

Built in the late 1960s, refurbishment and strengthening to the two-lane tunnel was identified as necessary in order to address over forty years of deterioration, and as part of a wider £25 million maintenance scheme of improvements to the Leeds Inner Ring Road.

Commenting on the successful shortlisting, Associate Director, Keith Barrow who oversees the northern division of VolkerLaser said:

“As VolkerLaser’s largest contract to date, the success of the Woodhouse Tunnel project has been a testament to our careful planning and expert execution of this logistically complex operation.

“Utilising a combination of traditional construction techniques and specialist repair and strengthening services, we have worked in close collaboration with Carillion and Leeds City Council to give new life to a critical piece of the city’s infrastructure with minimal interference to the general public. Everyone involved should be very proud of what has been achieved over the past two years.”

Gunite Group was employed by European Oat Millers  (EOM) to carry out significant external refurbishments to a concrete mill on its primary site in Bedford.

EOM is the second largest oat miller in Europe and processes over 120,000 tonnes of grain each year across its two sites. The eight storey 1940s concrete mill structure required significant refurbishment work as it was suffering from carbonation and chloride contamination.

Gunite Group worked closely with the client, and suppliers Flexcrete and Coverspan, to ensure that the process caused as little disruption to the mill as possible. Due to the food production nature of the site, the inside of the factory was fully protected to avoid contamination from the building works.

The glazing was removed, existing coatings were grit blasted and the defective concrete also removed. A full Flexcrete concrete system was then applied using Cemprotec MCI, Reinforcement Protector 841, Monomix and Monolite and to finish Curing Membrane WB.

Anti-carbonation protection was used to enhance the external façade.  A Monolevel FC fairing coat filled imperfections and voids, followed by an over-coating to provide protection against carbon dioxide diffusion.  The choice of protection was vital in this food production environment, so the water-based Monodex Smooth was used due to its ultra-low odour.

As the main contractor, Gunite worked with Coverspan who provided a Kingspan cladding system to replace the original glazing.  New canopies were built and encapsulated with the same Kingspan cladding system to finish the façade.

Mackenzie Construction recently completed works to install a cathodic protection system and conduct associated concrete repair works to Hammills Bridge, which carries the A762 over the White Cart Water in Paisley.

The use of a specialised underbridge access unit allowed works to be carried out during off-peak hours, with two lanes of traffic maintained in each direction during peak times.  The access unit also provided a safe means of access and egress to the works area, where the height restrictions under the bridge could fluctuate rapidly due to the river level.

Mackenzie Construction’s experienced Structural Repair Operatives completed the project on time and within a tight programme period.

Cemplas Waterproofing and Concrete Repairs Ltd has completed one of the largest concrete repair projects carried out in Central London, undertaking a £1.8m external façade refurbishment package on Royal Mail’s 120 year old Mount Pleasant operational site in London.

Working closely with architects Boyes Rees, project managers Rider Levett Bucknall, and the main contractor Mace, Cemplas operatives undertook work on over 10,000m2 of the building’s façade. Works included extensive structural concrete repairs, re-rendering, re-profiling fairing/levelling coats and applying final protective and decorative elastomeric coatings.

The execution of the works was fraught with logistical difficulties as the Royal Mail Centre had to remain fully operational throughout the entire process. The old façades to the two main complexes on the site had been surveyed in 2009, however, the extent of repair work required was far greater than the surveys had originally indicated. At varying times, Cemplas had a labour force of over 70 site operatives, together with an extensive site management team, in place.

Paramount in the final designs to the façades were the “Harlequin” relief panels to the North Façade, and the aesthetic finish to the South façade, which clearly demonstrated the ability of Cemplas.

This successfully completed project stands as a testament to Cemplas’ 45 years of experience and its ever increasing reputation. It is an excellent example of the large scale façade repair and refurbishment that Cemplas is able to undertake.

In June 2014, Freyssinet Ltd was appointed by North Somerset County Council’s (NSCC) as Principal Contractor for the £3m refurbishment works on the Yanley Lane Viaduct on the Long Ashton Bypass.

Constructed in 1968, the 298m x 13.7m viaduct carries the busy A370 dual carriageway over Yanley Lane and the main Bristol to Taunton railway line just south of Bristol City Centre. It is a 12 span simply supported structure with a composite steel deck, which was identified as requiring significant refurbishment in 2013, as part of NSCC’s planned maintenance programme.

The works to be undertaken included re-waterproofing and re-surfacing of the deck and the installation of new footways, parapets, mechanical deck joints and P4 terminal ends. Below deck, all 48no existing mechanical bearings were replaced with new pot bearings designed and manufactured in-house by Freyssinet Ltd.

To facilitate the bearing replacement works, the deck was supported on a bespoke temporary corbel arrangement, clamped at the top of each pier. These temporary works were also designed in-house by Freyssinet engineers.

Following the bearing replacement works, the entire steel deck was re-painted and a cathodic protection system was installed to the concrete columns supporting the deck. The works also included the application of a new protective coating to the existing deck beams.

The works were completed, on programme, on budget and to the satisfaction of the client in August 2015.

Concrete Repairs Limited is to provide structural and civil engineering maintenance and repair works to St Andrews Multi Storey Car Park in Norwich.

St Andrews MSCP, which opened in July 2005, is the largest car park in Norwich. The car park is of a steel frame construction supporting five suspended deck levels formed of pre-cast concrete planks and a cast in situ ground floor slab. The planks were overlaid with a structural reinforced concrete topping. Each of the decks and the ground floor concrete slab were then coated with an elastomeric decking system.

After four years, a number of defects were noticed both in the deck structures and the applied finishes/coatings. It was decided that props were required, resulting in around 50 spaces of the 1,084-space car park being put out of use.

The structural works will involve the renewal of the floor drains at each level, the removal of precast concrete planks and replacement with in situ reinforced concrete slabs, the installation of movement joints and the grouting up of voided precast plank ends. Full resurfacing of the Level 6 deck and partial resurfacing of the inter-decks and the bottom deck will be carried out, as well as the preparation and painting of corroded steelwork

The contract, which is being carried out in partnership with Norwich Property Services, is valued at £1.2 million. Disruption will be minimised, throughout the 16 week programme, with access to the car park and pedestrian walkways maintained at all times.

USL Special Projects provided embankment stabilisation at the Peel Centre in Blackburn, where the weight of an embankment on a failing gabion wall was pushing it forward and down into a service yard.

The gabion wall, which was 200m in length, 5m high and 4m deep, was failing due to the use of inadequate construction materials, the incorrect installation of the gabion structure and poor use of reclaimed materials within the embankment.

USL offered a methodology to ensure 100% void penetration. The solution involved sealing the front of the gabion wall with shotcrete and the injection of grout to fill voids and bind the structure together, utilising the gabion mesh present as reinforcement. Weeps holes were also installed at the base of the structure to allow the embankment to drain.

USL used ‘primary’ and ‘secondary’ injection ports, with the secondary ports ensuring free flow of air, preventing blockages and tracked the grout flow underground to provide a roadmap of progress. USL designed and manufactured dynamic probes at 2, 3 and 4m lengths to facilitate the varying depths.

Following the successful completion of two earlier phases of refurbishment at Gracechurch Shopping Centre (formerly The Mall), Makers were appointed to carry out a third phase of works including a significant volume of concrete deck repairs and re-waterproofing to approximately 6,500m2.

Prior to removal of the existing deck coatings, it was evident that there was significant presence of surface concrete defects that had already become delaminated as a result of reinforcement corrosion. A significant volume of repairs were required with all noisy works, such as concrete cutting and breaking out, being done out of hours to avoid disruption to the centre’s tenants and customers.

With the concrete broken out and exposed steel reinforcement prepared to remove all corrosion product, some 40m3 of concrete had to be reinstated to the decks to create a surface of a suitable profile onto which a new deck waterproofing system could be successfully applied.

In order to ensure full crack-bridging performance of the new deck waterproofing system, a reinforcing fleece was applied around the perimeter of all deck repairs, along with the over-banding of any static cracks and daywork joints. Triflex’s Deckfloor system was applied to the drive aisles, Triflex DCFC to the parking bays and Deckfloor Ramp to all up /down ramps. All were laid in contrasting colours to improve aesthetics.

There were approximately 100m of failed movement joints that required complete removal, followed by reinstatement with Emseal’s 50mm DSM joint to provide 100% watertight joints.

EPMS Supplies has opened a new Southern depot in Aylesford, Kent. The new depot, the company’s third, is strategically placed to enable EPMS to operate nationally.

EPMS prides itself on its friendly reliable service, technical know-how and support services. With over 100,000 items held in stock, it is a trusted partner for building companies and contractors.

EPMS works closely with specialist major manufacturers to provide leading brand products that offer the best cost effective solution to the customer. EPMS also offers a free of charge estimating service when requested and both on and off site technical support. All staff have excellent technical knowledge and vast practical experience.

The new depot can be contacted at Unit 5, Burnt Ash Trade Park, Burnt Ash Road, Quarrywood Industrial Estate, Aylesford, Kent, ME20 7XB; tel: 01622 963000; Email: markashworth@epms-supplies.co.uk

The Structural Concrete Alliance has announced the 2016 locations and dates for its free to attend regional Continuing Professional Development (CPD) seminars.

Designed to provide delegates with an introduction to Structural Asset Protection and Repair, these half-day events offer an introduction to corrosion as well as techniques for repair, protection and strengthening.

Presentations are varied to reflect the region in which the seminar takes place but include: An introduction to corrosion; An overview of electrochemical systems; Concrete repairs and coatings; Carbon fibre strengthening; Introduction to sprayed concrete; and Inspection of reinforced buildings & structures.

Six CPD seminars are scheduled for 2016:

• Brighton – March (day to be confirmed)
• Bath – 19 April
• York – 17 May
• Stirling – 20 September
• Chester – 11 October
• London – November (day to be confirmed)

For those unable to make the seminars, the Alliance also offers CPD presentations which can be delivered on-site to interested parties.