Ultra-High Performance Concrete
Ultra-High Performance Concrete (UHPC) is a versatile, high-strength, steel fibre-reinforced cement composite material, offering an impressive 150 to 180 MPa compressive strength.
For structural applications, the steel fibres in UHPC enable the material to transfer 8 to 9 MPa of tension and substantial shear without any traditional reinforcement. It is twice as stiff as conventional concrete, and is impermeable to water, chloride and oxygen, making its durability almost infinite.
The extremely dense matrix of UHPC, obtained from fine and ultra-fine particles, provides not only excellent structural properties but also the ability to achieve all sorts of textures and finishes. The architectural possibilities are excellent.
Freyssinet is leading the way to promote the use of Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) for repairs applications in the UK.
In 2015, Freyssinet used UHPC on the Hammersmith Flyover refurbishment project. The works took place in a congested urban environment, to a very tight programme, and as a result Freyssinet was required to innovate solutions in order to minimise the disruption to traffic, extend the serviceable life of the structure and minimise whole life costs.
The use of UHPC was one of the solutions developed by Freyssinet. The product made the project possible by providing a system to anchor additional post-tensioning tendons in a very compact manner. In total, more than 150 m3 of UHPC, both pre-cast and cast in-situ were used. The contribution of this innovation was not limited to the structural adequacy of the finished product on Hammersmith, but also its aesthetics, its durability and the speed and safety of the works. These were drastically improved compared to conventional techniques and materials.
Utilising its expertise in structural improvement, Freyssinet is launching ExoLeaf™, a range of UHPC thin products. The ExoLeaf™ system can be developed as pre-cast, cast in-situ or even sprayed, and as such it can be adapted to a wide range of applications and site conditions.
It is a particularly effective solution for time-restricted projects or those when disruptions to the structure need to be minimised. Corroded columns and beams, or structures requiring extra capacity for a new use can be treated quickly with ExoLeaf™. It is an effective strengthening solution which provides significant savings and increases the quality of the finished product.
Freyssinet prides itself on offering clients new techniques and products to serve their most complex requirements. The design, testing and site implementation of UHPC requires extensive expertise, of which Freyssinet has gained both in the UK and worldwide, developing innovative solutions that reinvigorate structures doomed for demolition, where conventional systems are not viable.
For more information on ExoLeaf™, email firstname.lastname@example.org or 01952 201901.
Download Freyssinet’s Exoleaf brochure here.