Starting in mid June 2021 and running over three consecutive weekends the LMS Highways team delivered over 113m³ of CRCP repairs, 548lm of joint sealing and 12m³ of thin bon repairs to both the East & Westbound carriageways of the A2, Boughton Bypass.
All sections of damaged carriageway were removed using either our 5 tonne vacuum lifting plate or our bespoke lifting bucket, which compared to traditional equipment are capable of lifting and removing large sections of concrete without the need for breaking down in advance.
Once these sections are removed we then proceed with prepping the bays with rebar before the concrete can be poured. Continuously reinforced concrete pavement (CRCP) is constructed with steel reinforcing bars placed within the concrete, continuously along the entire length of the pavement. The result is a continuous, smooth-riding surface capable of withstanding the heaviest traffic loads and the most adverse weather conditions.
Just shy of ten weeks later, in early September LMS Highways returned to Boughton Bypass to begin phase two of the package repairs which were delivered over ten consecutive weekends. Over this time the crews removed & repaired approximately:
During phase two of this project we were occasionally faced with severe weather conditions causing flooding throughout the site. This poses an issue as it prevents the concrete from being installed and in turn would delay the entire program schedule. For large scale projects such as these our team spends weeks meticulous planning and choreographing every aspect to ensure it’s delivered on time, on budget and with little to no disruption.
This prior planning ensures when we are faced with issues such as flooding, our teams have the measures in place to overcome and continue on with the project safely. Multiple water pumps were deployed to remove resting water from the bays and sandbag dams were placed to redirect the flowing water away from are working area.
Once the new bays are installed we then diamond saw cut the joints before applying primer and seal with a hot applied N1 sealant, this step prevents water ingress which in turn extends the service life of the new concrete bays.
Additional repairs were made to the surface cracking by performing Thin Bond Repairs. This is a repair designed to fix thin surface cracking due to pavement movement, repairing broken slab corners and to reform levels between slabs. Thin Bond Repairs are installed by firstly planing out the crack and surrounding area to the diameter of 200mm wide by 50mm deep. This is then primed and infilled using Maxi Crete, which is a BBA approved, resin based, flexible repair material.
LMS were instructed to remove old, damaged sections of concrete carriageway and prepare the subbase in preparation for the road to receive asphalt reinstatement. Along with this, partial depth concrete repairs and further life extension repairs such as thin bond and joint repairs have been provided.
In early February the team began prepping the site by marking the areas due to be repaired, joints were pre-sawn ahead of the breakout and many smaller repairs have been carried out to the joints. Often the forgotten part in any concrete carriageway maintenance regime is the joint sealing, keeping the water above the slabs and directing it to proper drainage is the number one priority to prevent undermining or softening of the subbase – otherwise cracked, dropped and/or rocking slabs can be the result. This is where carrying out a range of treatments from repair to replacement is necessary to extend the life of a concrete carriageway.
By mid Feb the LMS team, lead by Paul Burton who has over 32 years in the industry began to remove the concrete bays, a process which LMS Highways has refined over the years enabling them to work within the most challenging conditions and keep to extremely tight work schedules. This is achieved by having not only an experienced and highly trained workforce but specialist equipment such as our vacuum lifting plate which allows large sections of concrete to be removed in one continuous piece. Working alongside this is our custom-made lifting bucket which focuses on removing smaller pieces and the sections which are subject to heavy surfacing cracking where a vacuum seal isn’t possible.
Balvacs Project Manager Andrew Higson was on site during the first night of breakout and had the following comments. –
“I’m pleased to hear that we got the first 13 bays removed and reinstated as planned last night… and with an hour to spare. There was no luck involved in this. The coordination planning in the lead up, and the excellent communication (and safety controls) that I witnessed last night, were key to delivering these works successfully. This gives us real confidence that the programme for the next two weekends is achievable. Please pass on my thanks to your teams. Well done to all involved!” – Andrew Higson, Project Manager for Balvac
The second night of concrete removal for LMS was followed by similar success with comments of praise coming directly from Highways England. –
“Another big night with 13 bays removed and reinstated with base & binder, again this shows excellent communication and collaboration between contractors on site to achieve. Please pass on our thanks to everyone on site, who worked hard to achieve this.” – Lesley Bates, Highways England
“What a great achievement by everyone involved. Thank you for everyone’s hard work in the planning and undertaking of these works so far, this is a real success story. – Phil Deller, Project Manager for Highways England
With the project so far running, successfully, on-time and on-budget Paul Winter, Managing Director for LMS Highways shared his own comments on how he feels this project is going and how the feedback from both Balvac and Highways England has impacted the team.
“It’s always fantastic to hear our crews are delivering work ahead of schedule, as Andrew mentioned there’s so much prior planning and communication that goes into delivering this type of work so to have this recognised is very rewarding. We’re looking forward completing this project and continuing our working relationship with both Balvac and HE.” – Paul Winter, Managing Director for LMS Highways.
LMS Highways first started work with Alun Griffiths on the A449 in the summer of 2019, when we were called to provide emergency carriageway repairs due to an aircraft accident damaging the concrete bays. Since then we have continued our working relationship returning on multiple visits to provide full depth concrete bay replacements and inlaid crack repair throughout the North and South Bound Carriageway.
‘Having worked with LMS for a number of years now, they continue to provide an efficient service, particularly when faced with these emergency concrete carriageway repairs. Their innovative approach enables us to offer our client their preferred solution, limiting disruption to the highways network in South East Wales, whilst providing a quality end product that will last.’ – Alex Huges, Alun Griffiths
Maintaining a safe and usable highway network is crucial in these times to ensure our key workers can continue travelling to places of work and essential deliveries can be made throughout the country to those in need. To guarantee this remains possible, LMS Highways have been working tirelessly across the country providing operationally essential road repairs and in early November that included the A449.
We were instructed to repair a number of CRCP failures located on both the North and South bound carriageways. Continuously Reinforced Concrete Pavement is constructed with steel reinforcing bars placed within the concrete, continuously along the entire length of the pavement without any transverse joints. The result is a continuous, smooth-riding surface capable of withstanding the heaviest traffic loads and the most adverse weather conditions.
The teams refined process starts with the removal of the existing damaged surface, a vacuum-lift system is used to remove large, continuous sections of concrete in one complete piece and lifted straight onto a disposal truck. For smaller sections or areas with cracking a pecker and grab lorry are the safest and most efficient method of removal as the deep-set cracking throughout prevents a strong vacuum seal from being achieved.
With over 35 years’ experience in infrastructure our highly trained crews are capable of adapting our methods and processes immediately in order to best suit the requirements and variable conditions of a job.
Once they’ve finished removing the damaged concrete, the crew begin to prep the area with a waterproof membrane and reinforcing steel mesh which is run throughout to give added tension and strength to the concrete.
The concrete formula used for these repairs is known as rapid set and as the name suggests has an incredibly fast curing period which also doesn’t require conventional methods of leaving the repair to harden for between 7 and 28 days. This enables the team to keep to the time restricted schedule and return the carriageway at the end of each night, despite being faced with challenging winter conditions.
With this concrete formula and CRCP process the new surface benefits from greater durability, a longer life expectancy and gives the best long-term value of any pavement type with minimal maintenance requirements.
For some time, the concrete urban and residential streets in Kent County Council’s area have proven to be a maintenance headache for the local authority and their main contractor Eurovia.
The road refurbishment project which took approximately 10 weeks to complete included full depth concrete bay replacements, new kerbing, white lining and joint sealing which perfectly demonstrates the company’s unique ability to deliver a wide range of services under one point of accountability.
Running through from the beginning of July to early September 2019 saw the project being delivered during a UK heatwave. With temperatures reaching a high of 38 degrees Celsius proving challenging however this didn’t stop the team from finishing 3 days ahead of schedule.
With the hot weather additional care had to be taken as LMS were already using a rapid cure concrete to enable delivery of a tight programme. With concrete planned to cure in 24 hours at an ambient temperature of 18 degrees, the hot weather can give rise to problems with material work-ability / working time and there is also potential for the finished surface to crack if it is allowed to dry out too quickly. No problem for the LMS delivery team – the programme was adjusted to ensure pours were carried out on cooler days with greater cloud cover and also programmed concrete placement to take place first thing in the morning whilst substrate temperatures were at their lowest.
Concrete curing too fast isn’t normally a problem that needs to be solved. Typically clients are looking to have works carried out in as short a time frame as possible with roads opened to traffic after the shortest feasible curing period. Concrete normally needs to be left for 7 days to allow it to reach a suitable internal and surface strength to allow it to be trafficked. With increased traffic flows the ability to close lanes for this period is a rare luxury and LMS Highways have developed bay replacement systems that can be trafficked in as little as 4 hours!
Work on Sea Street brought with it a multitude of challenges including, limited space due to the heavy residential nature of the road and the extreme weather conditions. Despite these challenges, the LMS Highways team were able to work quickly within short-term partial closures, allowing residents much-needed access to their street and properties. That speed was achieved thanks to the team’ refined processes including in part, the removal of existing damaged surface. An innovative custom-built bucket system and a vacuum lifting plate is employed allowing large sections to be removed as one complete piece and lifted straight onto a disposal truck.
Throughout working on Sea Street, the engagement with residents had been excellent with many taking an interest in the methods used, great feedback being received regarding the low noise levels, fast turnaround and friendly accommodating attitude of the team on-site.
With over 1000 linear metres of concrete successfully removed and reinstated on both Old Thanet Way and Sea Street, providing the roads with an expected service life of 25 years.
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For various reasons due to the condition of the underlying surface, spot repairs have proven to be ineffective, costly and short-term with bad weather and heavy vehicle damage quickly causing more problems to repaired areas. Potholes, fretting and large-scale cracking not only cause potential liabilities from motorists damaging their vehicles but also lead to traffic chaos and residential complaints.
So it was with great interest to Eurovia in the summer of 2017 when one of their engineers received a video of LMS Civil Solutions’ respected concrete bay replacement process.
The service, which is normally provided on motorways and major routes is a particularly effective long-term solution and after a quick phone call leading to a meeting, all parties agreed that the process could be adapted and applied to an urban setting to provide a long-term solution to KCC’s problems.
A particularly powerful and unique feather in the bow of LMS Civil Solutions is that combined with LMS Highways’ service portfolio, the company can offer a “Kerb to Kerb” solution for the customer who also required other specialities within the scheme such as joint repairs, manhole and gully repairs and refurbishments and of course road marking reinstatement.
A decision was therefore taken to proceed with some key sites. The work commenced in late October with one of the key proving grounds being Cranborne Avenue, a residential street in Maidstone which connects directly with the busy A229.
Challenges included the heavily residential nature of the street and the fact that there was limited space due the roads and paths being reasonably narrow. Despite these challenges, the LMS Civil Solutions team were able to work quickly within short-term partial closures, allowing residents much-needed access to their street. That speed was achieved thanks to the team’s refined processes including in part, the speed of removal of the existing damaged surface. A vacuum-lift system is employed allowing larger sections to be removed as one complete piece and lifted straight onto a disposal truck. Smaller sections are removed using a grab and then just like the motorway version of the process the team immediately prepares the emptied area for the concrete pour. A waterproof membrane and reinforcing rebar is added and connecting dowel holes drilled.
The concrete formula is different to that used on trunk roads and has been chosen to specifically suit the urban environment. LMS Civil Solutions worked closely with Cemex to ensure a concrete product was used that provided the maximum combination of value for money and longevity.
Up to 35 linear metres full width can be replaced within a single day with trafficking possible after just 24 hours. The new surface benefits from an expected service life of 25 years.
Eurovia and Kent County Council were very pleased with the results and are evaluating the solution for several other sites in the area. Council engineers visited Cranborne Avenue during the works and were particularly impressed with the speed of removal due to the vacuum plate system.
“We were very impressed with the work at Cranborne Avenue and believe residents have been quite satisfied by the way this was handled. Not only was the work completed efficiently, on-time and on-budget but noise was kept to a minimum and it’s clear to see that the LMS Civil Solutions team have refined their processes very well to keep things on track. It is of particular value to us and our customer that LMS were able to cope with all the requirements on site and to provide a single point of accountability that works well.” Dave Gibbins – Contracts Manager Eurovia.
The experience of working in the residential environment and the nature of the underlying conditions have given Paul Burton who heads up the LMS Civil Solutions team, much food for thought.
“The specific experience of the condition of the surface from this site gave us some ideas of ways we could improve the removal process and make it even more efficient. Consequently, we’re testing a brand-new bucket which will be a UK exclusive for LMS Civil Solutions. This will enable us to remove a mixture of solid and broken concrete without the need to continuously change buckets.” Paul Burton – Project Manager LMS Civil Solutions.
Throughout the Cranborne Avenue project, residential engagement was excellent with residents taking an interest in the methods used with great feedback being received regarding the low noise levels, fast turnaround and friendly accommodating attitude of the team on-site.
When it comes to maintaining motorways in England, keeping maintenance and repairs to a high standard, short time-scale and within budget is imperative if disruption to the road user is to be kept to a minimum. The M180 is no different, running along the south side of the Humber and joining Grimsby to Doncaster, when the road surface began to fail prematurely in a significant and rapid manner, time was of the essence to investigate the cause, formulate a plan and repair before too much degradation caused major problems. This is where specialist contractors make all the difference especially with early engagement with the principal contractor.
A-one+ Integrated Highway Services is a highway engineering provider that designs, constructs and operates thousands of miles of road networks. Established by industry leaders, CH2M, Colas and Costain, A-one+ successfully manages Areas 4 and 12 of the Highways England road network. Over the last 7 years, A-one+ has worked with the team at LMS Highways Ltd, subcontract specialists in repair, in Areas 7 and 14 on various projects. It is times such as these when faced with the urgent repairs to the M180 that the historical working relationship between principle contractor and specialist contractor comes into its own. The team at Area 12 were unaware of the full repertoire of services that LMS Highways could deliver until a supply chain meeting when they realised they had found a contractor with the solutions.
“The package of specialist services supplied by LMS Highways supported the needs of the work well and made it a quick, efficient project with a single point of contact for the works.” Gareth Lewis – VM Manager A-One+.
The M180, a busy motorway in South Yorkshire, was suffering from water ingress problems causing large sections of the hard shoulder and areas of lane 1 to develop large cracks and potholes. The overlaid thin surface coarse had been re-laid in the previous few years with the expectation that this would last for 10-12 years as it had done previously. However, now it was failing prematurely, the hard shoulder and lane 1 needed to be closed, reducing capacity for the road user. The reason needed to be urgently investigated and the lanes reopened as quickly as possible.
A-one+ completed trial holes and FWD testing to identify if the wetlands either side of the motorway were causing drainage issues and waterlogging to the subbase. Agreements with Highways England meant that the project could and should be accelerated as the road surface was degrading rapidly during the investigation process. The question then raised, was how to repair it and how to do it quickly. A delegation from A-one+ attended one of LMS Highways’ popular Lunch and Learn events last year. Managing Director Paul Winter was talking about the successful launch of LMS Civil Solutions specialising in concrete bay replacements, in addition to the other works that the company delivers. This and the specialist knowledge and experience that the company has built up in the 30+ years of trading enabled the collaboration that this project needed.
The team at A-one+ recognised that to complete the required works to the timescales needed, using a mix of contractors simply wasn’t viable. Close project integration and assurance of programme was an absolute requirement, therefore one subcontractor with specialists in the following areas would keep the contractor interface simple and speed up the design process:
Works took place over a combination of nights/days and weekends to complete the project as quickly as possible. A-one+ milled out the surface course of the hard shoulder and lane 1 in preparation for LMS Highways to commence works. The LMS Civil Solutions team tackled the drainage first followed by 8 shifts of CRCP repairs. Simultaneously the LMS joint repair crews planed out and sealed transverse and longitudinal joints, completed thin bond repairs and plug joints. Once sections of road were completed, the surface course was re-laid, the road marking and road studs reinstated by the LMS road marking crew and the road reopened.
“From our point of view, from the very first discussion, it was a pleasure to work with A-one+. Not only did they have a very clear idea of the challenges but they were very keen to learn from the benefit of our experience in handling larger-scale repair schemes – we felt there was a great deal of collaboration in this scheme.” Paul Winter – Managing Director LMS Highways & LMS Civil Solutions.
Junction 2 slip roads of M180 were a little more complicated as the surface course could not be removed in advance and the busy junction could not be closed during normal hours. To avoid disruption to the road user the slip roads were surveyed in collaboration between A-one+ and LMS Highways prior to a complete weekend of junction closure. Over one weekend, the road was milled, repaired, surface course re-laid, road markings reinstated and road reopened ready for Monday morning rush hour.
Over a matter of weeks, over 11000 lm of joints repairs and 350m2 of CRCP repairs were carried out.
“The package of specialist services supplied by LMS Highways supported the needs of the work well and made it a quick, efficient project with a single point of contact for the works” commented Gareth Lewis, Value Manager – A-one+.“
By combining LMS Highways and LMS Civil Solutions highly experienced teams, they were uniquely placed in the market to deliver these works rapidly. This was due to a single-contractor interface, early contractor involvement and streamlined programming for the project, meaning the work was completed quickly and on-budget, avoiding costly delays for the road user. “From our point of view, from the very first discussion, it was a pleasure to work with A-one+. Not only did they have a very clear idea of the challenges but they were very keen to learn from the benefit of our experience in handling larger-scale repair schemes” said Paul Winter “we felt there was a great level of collaboration in this scheme“.
A-one + were completely satisfied with the solutions provided by the teams and are now looking at further projects in their areas where the LMS ‘Kerb to Kerb’ service would be beneficial.
The work which took place on an already planned overnight closure for other scheduled maintenance also included specialist pressure grouting work and LMS Highways proven concrete repair systems.
“I was very impressed with the process. The level of coordination between the gangs is very impressive to watch.”
The work took place in Norfolk on a busy trunk road with concrete sections. While overnight closures had already been earmarked for other essential maintenance, three of the bays were damaged beyond economical repair with a further 5 having dropped due to ground conditions and a further 25 requiring spot repairs.
On damaged concrete bays, a repair and maintain approach is normally preferred to the undesirable disruption of closing a major trunk road for a week or more to completely refurbish the surface. However, for concrete bays that have reached a certain level of decay, repair can be unsafe and is most likely uneconomical – the lifespan of these repairs is likely to be between 3-6 months due to the underlying condition of the bay.
As the bays requiring replacement were situated on a single carriageway stretch, access was limited, compounded by other scheduled maintenance work carried out.
The work was also adjacent to a housing estate so there was a pressing need for noise nuisance to be kept to a minimum.
“It appears to be a very viable long-term structural solution for the concrete sections.”
As well as the obvious cost savings compared to repeated repairs, our highly refined and efficient concrete bay replacement process perfectly solved the needs for the three bays requiring replacement.
The team started promptly at 8.30pm when the closure was initiated, ensuring that the noisier parts of the process were completed early.
To remove the bay, a vacuum-lift system is used to remove large sections of the slab in complete pieces. Not only is this a quick process but avoids the need for noisy jackhammer and other breaking equipment. If the slab is in a poor condition, two other sophisticated plant systems are used to efficiently remove smaller sections and debris.
The empty bay area is then drained of any residual water, cleared and prepared with a damp proof course and a high-performance drilling rig drills the holes for the horizontal steel dowels.
High specification concrete is poured and a friction screed applied before a drying tent is erected over the bay sealing in the heat from high-performance gas burners which will dry the concrete to the point it can be trafficked within 3-5 hours depending on ambient temperature conditions. The temperature of the concrete is measured continuously throughout the drying process. When it reaches the required temperature, the drying profile is analysed and only after strict checks is the bay certified for use by traffic.
Operations causing a noise nuisance were complete well before midnight, meeting the requirements of the customer.
Bay replacements completed and ready to be trafficked in less than 5 hours.
Expected lifespan of the replacement is 10 years.
Savings of over 85% over continuous repair regime.
The customer was extremely satisfied with the process.
“I was very impressed with the process. The level of coordination between the gangs is very impressive to watch and there is clearly a very strong leadership from the site supervisor. I observed the pre-shift briefing and was impressed with the level of detail and evident safety culture.
In addition, I was very pleased with the limited noise from the vacuum lifting system and how quick this part was completed, as I’m sure the local residents would agree!
To remove a damaged bay and to reinstate a brand new one in such a short period of time is an amazing achievement and we have identified a number of further projects that will benefit from this process. It appears to be a very viable long-term structural solution for the concrete sections.” Customer Project Manager