Community College, Bolton

The floor plates on this building are very complex and irregular due to architectural requirements e.g. some columns offset from the slab edge, slab steps, and a slab of 28m diameter. This last item was dealt with using two sets of tendons at right angles and this has worked out well on site despite some complex setting out of anchor positions around the curve. Shear dowels are used at some of the slab construction joints to reduce restraint effects and allow for long term movements. All pours on levels 1 – 4 are post tensioned with a total p.t. floor area of 12,000 m²; the slab depths vary but are mostly 250mm, 300mm or 350mm. The design calculations and drawings for all the post tensioned slabs have been by ConForce.

This is the first use of ConForce post tensioning in a college building although the components and methods used are similar to other types of buildings resulting in considerable reductions in slab depths compared to RC construction. Shear rails and precast columns, which are becoming commonplace on our projects and are resulting in a considerable reduction in site fixing time on each pour. When completed this will be a valuable addition to our ever expanding portfolio of projects throughout the U.K.