Freyssinet is awarded further contracts under HA Framework
Freyssinet Limited has recently been awarded three further contracts within the Highways Agency Area 9 &10, Construction Management Framework.
The works, which commenced on site in March 2012, include:
• A40 Bridstow Bridge – Concrete repair, cathodic protection, bearing refurbishment and joints
• M50 Queenhill Viaduct Phase 3 – Concrete repair, cathodic protection and drainage works
• M50 Pendock Sledge and Queens Arms – Concrete repair, cathodic protection and joints
The CMF is a collaborative approach to maintaining £75billion worth of assets for HA in these areas over the next 4 years. It consists of a number of different contractors from different specialist areas who work together to deliver network improvement and maintenance schemes on the all purpose trunk road and motorways in Highways Agency Area 9 and 10, which covers much of the West Midlands and North West.
Freyssinet Ltd, and their sister company Corrosion Control Services Ltd (CCSL), both form part of the CMF, having been selected for their skills and experience in concrete structure repairs and concrete corrosion prevention techniques.
To date Freyssinet Ltd and CCSL have completed six other contracts under the CMF agreement:
• AC5/AC7 Gravelly Hill – Concrete repair, bridge bearing replacement works and cathodic protection
• Oldbury Viaduct – Cathodic protection
• M6 Rayhall Viaduct – Concrete repair and cathodic protection
• M50 Kempley Road Bridge – Concrete repair
• M5 Northway Decks – Concrete repair and deck strengthening
• Bromford Viaduct – Concrete repair and cathodic protection
The CMF contract is different to the traditional sub contract relationship. It is based on partnering, encouraging open working relationships and providing opportunity to develop and share innovative practices.
Freyssinet Complete Further Works Under Highways Agency Framework
Freyssinet Limited are continuing to work successfully in collaboration with other specialist contractors under the Highways Agency Area 9 & 10, Construction Management Framework.
The CMF is a collaborative approach to maintaining £75billion worth of assets for HA in these areas over the next 4 years. It consists of a number of different contractors from different specialist areas who work together to deliver network improvement and maintenance schemes on the all purpose trunk road and motorways in Highways Agency Area 9 and 10, which covers much of the West Midlands and North West.
Bromford Viaduct is one of a number of viaducts forming the Midland Link Motorway Viaducts (MLMVs). There are 21km of elevated motorway comprising 1200 no. cross beams and 3600 no. columns, constructed between 1969 and 1972.
During the mid 1980s corrosion started to occur due to de-icing salts leaking through deck expansion joints onto cross beams. Initial preventative measures, such as placing gutters beneath the expansion joints, were implemented during the mid – late 1980s and repair works in 1990. Concrete repair and cathodic protection schemes have been on-going to the present day based on calculated intervention dates for each cross beam. Repair Contract 153 (R153) commenced in January 2011 and comprises of 8 no. cross beams. With Amey acting as Principle Contractor, Freyssinet Limited was appointed as a specialist contractor within the Highways Agency Area 9 &10 CMF.
The scope of works involved removing sections of concrete to be repaired by saw cutting and hydrodemolition, undertaken by Freyssinet’s own in-house hydrodemolition team. Repairs were carried out as necessary to reinforcement steel, and the areas re-instated using flowable concrete, with some beams repaired under a supported condition.
Cathodic protection to 2 no. beams involved the installation of Galvanic (Sacrificial) anodes, whilst the remaining 6 no. beams had an Impressed Current Cathodic Protection (ICCP) system installed. The ICCP was designed as a 3 no. zone system; zone 1 to the shear walls being a ribbon mesh primary anode with a spray applied conductive overlay, zone 2 to the beam top and upper section of the beam sides being a ribbon mesh anode with non-conductive repair mortar overlay, and zone 3 to the lower section of beam sides, beam soffit and top of columns being a similar system as zone 2.
Technical issues which prevented supporting steel work being erected to underside of 2 no. cross beams threatened to cause delays to the programmed works, and Freyssinet’s installation of the CP system in particular. Successful cooperation between all parties resolved this situation, and the works were re-sequenced to enable Freyssinet to begin installation works ahead of programme by utilising concrete curing periods where there was no other activity taking place in the work area.
The designers also re-sequenced concrete repair works so that as far as practical, whichever half of each beam needing least repair was concentrated on in initial repair stages and would be complete in advance of the other half of beam, freeing up nearly 50% of CP installation work to be done before completion of concrete repairs. This method was applied to all beams where programmed work extended beyond Christmas 2011.
Utilising Freyssinet’s own in-house hydrodemolition team contributed to the success of the new programme. Where concrete surface hydro-prep was required for overlay material, the team was able to mobilise immediately, taking advantage of short durations of concrete curing time, all the time pulling back the programme.
The cathodic protection on R153 was commissioned with performance verification taking place 45 days after ‘switch-on’ in early December 2011.
Successful cooperation between all parties resulted in the programme being pulled back to mid December 2011, offering the client savings in terms of both time and money.
Concrete Bridge and Highway Structure Repairs, Strengthening and Hydro-Demolition
Freyssinet Limited is an expert provider of concrete bridge repairs and structural concrete refurbishment. Owing to their experience and excellent track-record in bridge and highway structure repair and all aspects of concrete repair, the Highways Agency and numerous Local Authorities are regular clients.
Coatings
Pore-lining impregnants are often applied to bridges exposed to chlorides before they are opened to traffic. However, when the level of chloride reaches reinforcement depth the coating will not stop corrosion and permanent concrete bridge repairs will need to be done.
Patch Repairs
Patch concrete repairs have historically been the conventional method of concrete bridge repair. However, this method requires the removal of undamaged (but chloride-contaminated) concrete which is otherwise in sound condition. In addition, patch repairs inevitably increase the corrosion in surrounding areas of concrete.
Electro-chemical Cathodic Protection (CP) – Concrete Corrosion Prevention
The Cathodic Protection method does not require the removal and replacement of chloride-contaminated, but otherwise sound, concrete. This significantly cuts concrete quantities and reduces on-site working time, minimising the cost of concrete repairs to bridges and highway structures.
Hydro-demolition for Bridge and Highway Structure Repair
As part of its forward-thinking approach to structural concrete refurbishment, Freyssinet offers clients the advantages of hydro-demolition concrete removal by their own in-house teams.
Efficient Concrete Removal Hydro-demolition is a high-pressure, water-jetting technique for the efficient removal of both damaged and sound concrete. It can be used with equal effectiveness on small areas of localised damage, for extensive concrete repairs preparation and for removing existing concrete coatings. Hydro-demolition is an excellent preparation for concrete repairs, leaving a perfect bonding surface for new coatings and all types of concrete repair material.
Advantages of Hydro-demolition for Bridge and Highway Structure Repair Hydro-demolition offers a number of important advantages in comparison to conventional concrete removal methods used in concrete bridge repairs and other concrete structures e.g. jackhammer removal.
• Eliminates all dust and debris
• Cleans existing reinforcing steel
• More efficient process reducing on-site programme
• No damage to reinforcing steel
• No hand-arm vibration injuries
• No vibrations ensures no cracking or micro fractures in the structure
• Surfaces are prepared perfectly to key-in new concrete and receive mesh overlay
Experienced Team The Freyssinet Limited hydro-demolition team is highly trained with more than 20 years of solid experience in hydro-demolition applications including concrete bridge repairs and all types of concrete structures.
Health, Safety and Quality The hydro-demolition team wears the latest TST PPE, including 2000 bar-rated bib and brace, TST safety gaiters to cover safety wellington boots and TST waistcoats.
Freyssinet Limited is an Accredited Full Member of the Water Jetting Association – with a representative on the Technical Committee. All of their work is carried out with rigorous adherence to the Water Jetting Association’s Code of Practice.
Hydro-demolition is an important component of Freyssinet Limited’s unique, one-stop service for concrete bridge and highway structure repairs. Other services include:
• Bearing replacement
• Carbon-fibre strengthening
• Cathodic protection
• Coatings
• Concrete repairs
• Core drilling
• Grit blasting
• Jacking
• Wall sawing
Comprehensive Range of Freyssinet Services for Durable Concrete Repair and Refurbishment in Scotland
Freyssinet Limited has been providing first-class structural concrete repairs in Scotland and the rest of the UK for more than 30 years, offering a comprehensive range of structural concrete refurbishment and long-term repair techniques depending on the type of structure, the type of damage and the extent of concrete deterioration.
Concrete Bridge and Concrete Building Repair in Scotland
Freyssinet is a specialist bearing manufacturer producing standard and customised bearing design for concrete bridge repairs. If required, prior to bearing replacement, inspection and testing is carried out by our experts in Scotland. Freyssinet’s expert services include every other aspect of a high quality concrete bridge repair.
The range of techniques available for concrete bridge and concrete building repairs in Scotland includes:
• Modified mortars for patch and thin-bond repairs
• Pressure and vacuum injection using epoxy, polyester and cementitious grout
• Sprayed concrete – both wet- and dry-sprayed concrete structural repairs
• Expert hydrodemolition concrete removal
Hand- and machine-applied concrete repair mortar is appropriate for structural and non-structural concrete repairs. Hand application is suitable for small-scale concrete repairs and sprayed concrete is used on large-scale structural concrete refurbishment.
Strengthening
Freyssinet offers a range of highly effective strengthening techniques for structural concrete refurbishment in Scotland to prolong the life-span of existing structures or allow a change of use. These high-grade concrete structure repairs include:
• Column strengthening,
• Bridge deck strengthening
• Raising allowable floor slab loads
• Strengthening around new openings
External post-tensioning
This method is especially suitable for concrete bridge strengthening and Freyssinet offer an expert in-house design and installation service of supplemental post-tensioning to existing structures. Additional tendons can be fitted within the structure or externally depending on the size of the bridge. External post-tensioning is also a highly effective concrete structure repair technique for upgrading circular storage tanks in Scotland and the rest of the UK.
Plate bonding
Plate bonding is carried out by Freyssinet to provide an excellent strengthening method for under-strength beams and floor slabs.
Freyssibar high-strength bars
Freyssibars are versatile, high-strength bars used to introduce pre-stress into existing areas which are subject to bursting force or high stress concentrations. For example, concrete structure repair to bridge deck diaphragms, anchorage regions and column heads. In addition, Freyssibars provide a significant increase in load-carrying capacity and are a suitable alternative to plate bonding.
FRP Composites
Freyssinet also offers TFC®, a carbon-fibre product developed by the Freyssinet Group. TFC® has numerous strengthening applications for concrete structural repairs in Scotland. For example, beam strengthening, column-wrapping, reinforcement around new openings and floor slab strengthening.
Freyssinet One-stop Design and Build Service
Strengthening techniques required for concrete bridge and concrete building repairs demand careful consideration of the existing and desired loading regimes to assess what strengthening methods are viable and to facilitate a technically appropriate, cost-effective design. Freyssinet has a highly-qualified and experienced team available to offer clients a comprehensive design and build service for concrete repairs in Scotland.
Innovative Techniques
Innovative Cathodic Protection (CP), Chloride Migration and Re-alkalisation are modern techniques which have been used with success in hundreds of structures worldwide. Furthermore, electro-chemical methods have been approved by the Highways Agency for use in concrete corrosion prevention in Scotland and the rest of the UK. Chloride Migration is available as a technique for structural concrete refurbishment in Scotland, providing an excellent concrete corrosion prevention treatment. Re-alkalisation is the newest method for carbonated concrete structures in Scotland and worldwide.
Freyssinet Limited is a forward-thinking and highly experienced company, offering technically sound and cost-effective concrete repair and structural concrete refurbishment techniques in Scotland and the UK.
The Freyssinet Solution: Innovative Concrete Corrosion Prevention
Freyssinet Limited is able to offer clients a comprehensive, one stop service for the design and installation of concrete corrosion prevention systems.
In partnership with their sister company Corrosion Control Services Limited (CCSL), Freyssinet install permanent cathodic protection systems for the continuous protection of concrete structures exposed to chloride contamination or carbonation.
CCSL provides expert assessment, design and component supply and Freyssinet undertake the installation, associated concrete repairs and application of coatings. This provides clients with an integrated service supervised by one named contact, offering both time and cost savings for clients who would otherwise need to organise and oversee several sub-contractors. In this way, overall responsibility for the success of each concrete corrosion prevention project is clearly defined.
The Problems
Reinforcement corrosion is the major element causing concrete deterioration and requiring structural concrete refurbishment. Good quality concrete creates a high alkaline setting for steel reinforcement, but if the level of alkalinity diminishes, the steel becomes increasingly susceptible to corrosion.
Corrosive rust formation increases the volume of the reinforcement until the expansive force becomes sufficient to cause the surrounding concrete to crack and spall. There are two main causes of the type of severe concrete deterioration that requires extensive structural concrete refurbishment and long-term concrete corrosion prevention treatment:
1. Carbonation The process of carbonation occurs when atmospheric CO2 dissolves in moisture forming carbonic acid. The acid progressively penetrates and reacts with concrete, decreasing the pH value. When the contamination penetrates as far as the reinforcement layer, the steel is de-passivated and starts to corrode. Freyssinet can assist in halting this carbonation damage by applying re-alkalisation and structural concrete refurbishment methods.
2. Chloride Contamination De-icing salts, marine aggregates and sea water are common sources of chlorides. When chlorides manage to penetrate to the reinforcement layer, they attack the steel aggressively, starting corrosion. The rate of progression of carbonation and chloride contamination depend on:
• Quantity of CO2 present in the atmosphere/chlorides on the concrete surface
• Concrete permeability/density
• Concrete moisture content
Cracked or poor quality concrete in need of widespread structural concrete refurbishment will deteriorate more rapidly. Freyssinet are able to halt the corrosion process and provide concrete corrosion prevention by the application of innovative electro-chemical cathodic protection.
The Freyssinet Solution
Conventional patch repairs to damaged concrete are unlikely to provide successful concrete corrosion prevention when carbonation has penetrated behind the reinforcement layer or where there is severe chloride contamination in the surrounding, untreated concrete.
Freyssinet carries out cathodic protection as a long-term concrete corrosion prevention technique, which works by passing a small electric current through the reinforcement. This innovative method has been used in several hundred successful concrete corrosion prevention repairs around the world and offers a number of important advantages over other structural concrete refurbishment techniques:
• Continuous concrete corrosion prevention stops corrosion and prevents future attack
• Permanent solution that never requires re-application
• Highly effective even on severely damaged concrete
• Effective against both carbonation and chloride attack
• Effectiveness can be controlled and monitored – economically and simply
• Conservation of large areas of contaminated but sound concrete
• Shorter on-site work duration
• Reduced need for temporary propping
• More cost-effective than complete replacement
• Perfectly suited to marine structures and highways with recurrent contamination
One-stop service provider
Concrete corrosion prevention and structural concrete refurbishment are becoming increasingly necessary to deal with the cracking and spalling problems of ageing stone and masonry-clad buildings with steel frames.
Freyssinet is a leading provider of a comprehensive range of concrete repair and maintenance techniques – able to offer a one-stop contracting service for all concrete repairs and structural concrete refurbishments.
Owing to an outstanding track-record in all aspects of concrete repair, The Highways Agency and various Local Authorities are valued clients. Freyssinet offers valuable, impartial advice on the selection of the best methods and high-quality materials for individual projects and their experts are always available to discuss your requirements.
Freyssinet Ltd Continues to Excel at Bridge Bearing Replacement Contracts
Freyssinet’s origins are as a specialist in bridge construction and the manufacture of bridge bearings. Their knowledge and expertise in this area remain unparalleled. An extensive track record of bridge work illustrates their capabilities to complete projects both large and small, and always to the highest standard.
During 2011 Freyssinet has sustained their success in this area, completing a number of bridge bearing replacement contracts throughout the UK.
Freyssinet Ltd were appointed by Jackson Civil Engineering to design, manufacture and install two new mechanical bridge bearings on the A14 Orwell Bridge in Ipswich, as part of the Highways Agency Area 6 Framework. Jacking and monitoring of the deck was also included within Freyssinet’s scope of works.
Overseen by Contracts Manager, Gavin Thomas, the bridge bearing replacement works were carried out during a 52hour closure of the North Deck, carrying the Eastbound A14, over the weekend of 11th-14th February 2011.
Prior to the possession, 3no jacking systems coupled with a computerised monitoring system were installed and commissioned to enable a controlled lift of the deck. The main lifting jacks were positioned on the pier top acting to the underside of the deck with a maximum uplift capacity of 3500Tonnes.
Due to the reduced capacity of the bridge box at the jacking point, a further 2 sets of jacks were installed within the bridge box to effectively brace the box and resist the forces induced via the main lifting jacks. The sets of internal jacks used were Vertical Strut Jacks with a maximum capacity of 2240Te and Diagonal Strut Jacks with a maximum capacity of 1400Te.
Once the deck had been jacked to the required height, the existing bridge bearings were removed and replaced with new. Each bearing weighed approximately 3Tonnes and had a vertical capacity of 1600Tonnes at SLS.
In March Freyssinet Ltd commenced work in Peterborough, completing bridge bearing replacement and concrete repairs for Osborne Ltd on the A1260 dual carriageway. The road, also known as the “Nene Parkway”, serves as major trunk road from the southern end to the northern end of Peterborough, circumventing the city centre. The purpose of the works was to both prolong the life of the bridge structures and enable them to continue to cope with increasing levels of traffic. The works were considered essential by Peterborough City Council; if the bridges had deteriorated further the stability and integrity of the structures would have been compromised.
A total of 7 bridge structures were included in this contract which involved the complete replacement of 12no pier crossheads on each of 4 bridges at two interchanges on the A1260 trunk road at Peterborough, and also associated concrete repair works. Concrete repairs were also carried out on 3 other nearby structures concurrent to the main works.
Each bridge was a 4 span simply supported structure, with the deck being constructed from 28 inverted ‘T‘ beams, supported at each end on 28 elastomeric pads. The elastomeric pads were due for routine replacement and Peterborough City Council decided to re-design the pier crosshead and change the support at each span end from 28no elastomeric pads to 12no elastomeric pads and 1no mechanical shear key.
This re-design would enable any future jacking of the deck to be carried out from the pier top removing the need for extensive steel temporary works.
Bespoke steel trestles were erected on either side of the pier to be strengthened. The trestles incorporated 8no 250Tonne pot jacks with mechanical bearings on top of them to enable the deck to move and rotate during the works.
The top 1.5m of the pier was removed using hydro-demolition and re-cast to the new design.
New elastomeric pads were installed on the newly formed plinths. Once the new concrete pier head had achieved the required strength, the deck was de-jacked onto its new supports and the temporary works were relocated to the next pier so that the process could be repeated.
Freyssinet Ltd was appointed by Birse Civils Ltd in April to carry out the scheduled replacement of roller bearings to 3no overbridges on the M27 motorway near Southampton.
Bespoke temporary works were designed and installed by Freyssinet Ltd. The bridge deck was then jacked to release the load from the existing bearings, the existing roller bearings were then replaced with new mechanical bearings, which were again designed and manufactured by Freyssinet Ltd’s own in-house team.
The main criteria for these works was to minimise the time period for traffic management on the M27, therefore in order to expedite the replacement process, the existing upper and lower casting plates were reused removing the curing process of new concrete & grout from the installation process. A new Highways Agency approved protective coating system was installed on these plates.
As the existing upper and lower cast in plates were found not be horizontal or parallel to each other, compound taper plates were manufactured to create horizontal and parallel bearing surfaces; these plates were installed to very tight tolerances to enable the accurate installation of the new mechanical bearings.
In June Freyssinet were selected by Southampton City Council to carry out bridge bearing replacement and concrete repairs on Itchen Bridge as part of a routine maintenance contract.
Freyssinet Ltd acted as Main Contractor and the scope of works consisted of jacking and bearing replacement, protective coating, concrete repairs and all associated works, including temporary works and traffic management.
Bespoke temporary works were designed and manufactured by Freyssinet Ltd incorporating high capacity hydraulic jacks. These were installed to support the deck during the works at the suspended span half joints and piers.
A total of 22no mechanical bearings were replaced; 12no mechanical bearings at the free end of the suspended spans, 2no at the East Abutment and 8no at prioritised piers. All of the bridge bearings were designed and manufactured by Freyssinet Ltd’s own in-house team.
The existing bearings were removed using high pressure water jetting and the new mechanical bearings were then cast into the structure prior to de-jacking the deck onto its new supports.
Whilst these critical path works were ongoing, other ‘off-line’ works such as re-wiring the internal boxes and the installation of new expansion joints were undertaken. A total of 6no expansion joints were replaced on the bridge deck during one weekend closure of the deck.
Maintenance was also carried out on all other bearings within the structure, including the application of new protective coating system.
Re-profiling works were completed on the East and West revetments to the abutments, installation of high security access doors were installed through the abutment cheek walls into the abutment chambers and the internal box lighting systems were completely rewired. Concrete repair works were also carried out as necessary by Freyssinet Ltd’s specialist operatives.
Each of these contacts was completed on programme and within budget, to the satisfaction of the contractors and the clients.
Repairs and strengthening work, and bridge bearing replacement contracts in particular continue to represent a significant proportion of Freyssinet Ltd’s turnover, demonstrating their capabilities to continuously execute this type of work to a high standard.
Freyssinet Ltd’s collaboration with the Highways Agency continues
Freyssinet Ltd, and their sister company Corrosion Control Services Limited (CCSL), form part of the Highways Agency Area 9 &10, Construction Management Framework.
The CMF is a collaborative approach to maintaining £75billion worth of assets for HA in these areas over the next 4 years. It consists of a number of different contractors from different specialist areas who work together to deliver network improvement and maintenance schemes on the all purpose trunk road and motorways in Highways Agency Area 9 and 10, which covers much of the West Midlands and North West.
Following a comprehensive application process, Freyssinet were selected as the specialist contractor for Concrete repairs and Cathodic Protection (in a joint venture with CCSL).
The Companies were assessed on their experience and track record of work, as well as in terms of health and safety, quality and environmental policies and procedures.
The CMF began in January 2010, and the contract will run for 4 years with a possible 2 year extension.
To date Freyssinet Ltd and CCSL have completed 4 contracts under the CMF agreement:
• AC5/AC7 Gravelly Hill – concrete repair, bridge bearing replacement works and cathodic protection
• R153 Oldbury – cathodic protection
• M50 Kempley Road Bridge – concrete repair
• M5 Northway Decks – concrete repair
Works are due to commence on site at R159 in August 2011.
The CMF contract is different to the traditional sub contract relationship. It is based on partnering, encouraging open working relationships and providing opportunity to develop and share innovative practices.
A14 Orwell Bridge Bearing Replacement
The A14 Orwell Bridge, completed in 1982, is situated to the South East of Ipswich, Suffolk. It is a 1.3km, eighteen span continuous twin post-tensioned concrete box girder viaduct, carrying the A14 Trunk Road over the River Orwell estuary.
The scheme, part of the Highways Agency Area 6 Framework, was the scheduled replacement of two mechanical bearings supporting the North box on Pier Line 5, along with associated temporary works to facilitate jacking of the deck and to control the potential release of stored energy within the existing bridge bearings. Pier Line 5 is approximately 35 metres high.
Freyssinet Ltd was appointed by Principle Contactor Jackson Civil Engineering to design, manufacture and install the new bearings. Jacking and monitoring of the deck was also included within Freyssinet’s scope of works.
The bridge bearing replacement works were carried out during a 52hour closure of the North Deck, carrying the Eastbound A14, over the weekend of 11th-14th February 2011.
Prior to the possession, 3no jacking systems coupled with a computerised monitoring system were installed and commissioned to enable a controlled lift of the deck. The main lifting jacks were positioned on the pier top acting to the underside of the deck with a maximum uplift capacity of 3500Tonnes.
Due to the reduced capacity of the bridge box at the jacking point, a further 2 sets of jacks were installed within the bridge box to effectively brace the box and resist the forces induced via the main lifting jacks. The sets of internal jacks used were Vertical Strut Jacks with a maximum capacity of 2240Te and Diagonal Strut Jacks with a maximum capacity of 1400Te.
Once the deck had been jacked to the required height, the existing bridge bearings were removed and replaced with 2no new mechanical sliding bearings, designed and manufactured by Freyssinet Ltd. Each bearing weighed approximately 3Tonnes and had a vertical capacity of 1600Tonnes at SLS.
The deck was handed back to the Client 2 hours ahead of schedule. Works were completed to the satisfaction of the Highways Agency and Jackson Civil Engineering, on time and within budget.
Why not learn more about Freyssinet’s bridge bearing replacement services for both repair and new structure projects?