Client
Lendlease
Value
£475,000
Sectors & Services
Buildings Repairs & Refurbishment Structural Strengthening Projects
1 Triton Square is a prominent commercial building located within British Land’s Regent’s Place campus in London’s West End. Originally designed in the 1990s by Arup, the building required significant adaptation to meet modern workspace demands. As part of a major refurbishment led by British Land in collaboration with Arup and Lendlease, four additional storeys were added to the structure.
This introduced increased loading demands on the existing reinforced concrete columns. To avoid enlarging column dimensions and reducing net lettable floor area, an innovative structural strengthening solution was required. Carbon fibre reinforced polymer (CFRP) wrapping was selected to enhance column capacity while preserving architectural and commercial efficiency.
Services undertaken
-
Structural surveys to assess concrete strength, reinforcement layout and adhesion values
-
Concrete testing including compressive strength and pull off testing
-
Vacuum grit blasting to prepare column surfaces for bonding
-
Priming of columns using Sikadur 330
-
Supply and installation of carbon fibre wrap to 29 columns
-
Installation of Sikawrap 900C in multiple layers using Sikadur 300 resin
-
Quality assurance inspections and post cure integrity checks
-
Testing of control and site samples
The addition of four storeys required careful consideration of how increased axial and bending loads would be transferred through the existing structural frame. Arup and Sika developed a strengthening strategy using carbon fibre fabric to confine and enhance the load carrying capacity of key reinforced concrete columns without altering their geometry. Following an extended design and analysis period, CRL was appointed to deliver the specialist installation works.
Prior to installation, CRL undertook comprehensive structural surveys to verify concrete compressive strength, reinforcement layout and bond performance through pull off testing. This rigorous pre construction verification ensured the CFRP system could be installed in full accordance with the design assumptions. Column surfaces were then meticulously prepared using vacuum grit blasting to achieve the required surface profile and cleanliness for resin bonding.
Each of the 29 columns, measuring approximately 3.5 metres in height, was primed using Sikadur 330 before being wrapped with between two and five layers of Sikawrap 900C carbon fibre fabric embedded in Sikadur 300 resin. Installation quality was critical to system performance, and CRL’s specialist technicians achieved a defect free finish with no voids, air entrapment or debonding, confirmed through post cure inspections.
Extensive control and site sample testing formed part of the quality assurance process. CRL successfully met an exhaustive QA inspection regime overseen by Arup, Lendlease and Sika, with Sika recognising the works as the highest quality CFRP installation they had observed. This project represents CRL’s largest carbon fibre strengthening scheme to date and demonstrates their technical leadership in advanced structural repairs UK solutions.
"The team working on site worked well together and proved they are more than capable of
carrying out the works."
James Squire | Product Manager - Refurbishment | Sika Limited
The CFRP wrapping system provides long term structural enhancement by increasing column confinement, improving bending capacity and mitigating the risk of future overstressing due to increased building loads. As a non intrusive strengthening solution, it avoids demolition, additional dead load and ongoing maintenance associated with traditional concrete or steel jacketing.
Careful surface preparation and controlled resin application ensure durable bond performance, critical to the long term effectiveness of the system. By preserving column dimensions, the solution safeguards usable floor area while extending the structural service life of the building. CRL’s expertise in advanced strengthening techniques supports resilient asset management outcomes, delivering a robust, low maintenance intervention that enables existing structures to adapt safely to evolving operational demands.
