The prevention of punching shear failure with flat slab construction is a critical consideration and while traditional solutions such as links in the punching area work fairly effectively, they have disadvantages in that they are both time-consuming to install and have the risk of installation inaccuracy and positional stability during concreting.
A product that does offer a cost-effective, easy-to-install solution, is the widely used and dependable Schöck Bole shear rail; and one of the many construction sites where Schöck Bole is the system of choice is the New Green project at Rainham in Essex. A number of council estates are planned for regeneration in the area, as a joint venture between the London Borough of Havering and Wates Residential. Known as the ’12 Estates’ regeneration programme, it will see around 5,200 homes delivered in Havering over the next 12 to 15 years and the earliest of these is the replacement of Napier and New Plymouth House. Two outdated 13-storey tower blocks which are being replaced by mid-rise, high density buildings, providing 197 homes arranged around new open spaces.
Signifcantly faster installation with Bole
As with any reinforced concrete slab design, the New Green project is at risk of punching shear failure, which traditionally has been resolved by adding further concrete, such as the use of downstand beams or localised thickened column heads. However these measures require complex formwork and significantly reduce the benefits offered by the flat slab design. By incorporating the Schöck Bole shear rail system at New Green, installation is cost-effective and significantly faster than traditional loose links.
The ready-to-install reinforcement element consists of double-headed studs with spacing bars to ensure correct positioning. Spacers allow installation on the formwork and as a result, installation on the construction site and in the precast plant is therefore quicker, safer and easier to achieve. Two spacer bars are welded to the vertical studs, which ensure the correct distance between uprights. The forged stud heads guarantee a perfect finishing bond with the concrete. The dramatically reduced fixing time far outweighs any additional material costs that may be involved with a prefabricated system.
Schöck offers two other variants
Schöck has developed two other punching shear reinforcement variants. The type U, designed for installation before the lower mat and type O for installation after the top reinforcement layer. All products in the range are designed to Eurocode 2 and supplied ready for installation. There is downloadable user-friendly Schöck design software available too, which enables fast and simple dimensioning of the product.
For further information on the Schöck Bole system contact the company on 01865 290 890 or visit www.schoeck.co.uk