CCL‘s post-tensioning expertise and specialised engineered solutions create curved slabs on this modern rebuild of a UK school.
Skinners Academy is a multi-million pound rebuild of Turnbridge Wells high school intended to create a new 21st century learning experience.
CCL completed the design, supply and installation of all suspended post-tensioned floor slabs using its XF system. The structure features long spanning, curved slabs with large voids. The company’s main objectives were to reduce costs with savings in slab depth compared to the original reinforced concrete scheme, maximise floor-to-ceiling space, reduce the number of beams required and increase the speed of construction.
Typically a 275 mm thick flat-slab solution was proposed throughout blocks B, C and D, and 325-350 mm in block A. The company utilised drop heads in order to address the issue of punching shear at some column locations caused by changes in loading requirements.
Curved tendons presented difficulty in stressing, requiring CCL to stress the tendons from the inside, to the outside to prevent trapping of the strand and to achieve theoretical extensions. Due to on-site programme amendments the installation of a precast staircase was required, however, access was restricted. To overcome this issue CCL created a temporary construction joint and added an additional sub-pour thereby allowing access for the staircase installation.
An additional pour strip was also required to permit stressing after further changes to on-site pour sequences caused access difficulties.
