Demolition, Groundworks and Foundations for a New School Building
These two contracts were for the same client, and of similar design, and run simultaneously. The works comprised the installation of RC foundation beams and a ground floor slabs, (for new 2-storey steel framed buildings), and new storm and surface water drainage systems for the areas.
The groundworks included the removal of existing hardstandings, and a reduced level excavation of the new building areas. The CBR’s at formation level were quite low, which necessitated the placement of a thick crushed concrete piling mat to allow the piling rig to traverse the area. The crushed concrete was generated by using a mobile crushing plant to re-cycle the concrete, brick, and tarmac rubble generated by the demolition of two of the existing school buildings.
The steel frame was supported by RC groundbeams, with the holding down bolts cast into the beams. The ground beams also acted as a perimeter support for the suspended ground floor RC slabs, which covered an area of 1500m² at Parkfield School, and 2500 m² at The Hyde School.
The ground floor slab was cast on top of void formers. After the concrete had gained sufficient strength to be self supporting, water is poured into the void formers through tubes cast into the slab, which effectively cause the formers to collapse. The void created then allows the underlying clay soils to ‘heave’, without causing any uplift to the floor slab.
These contracts are still to be completed next year. Once the new buildings have been commissioned, and the schools have moved into them, we are to demolish the old school buildings and construct new playgrounds, sports pitches, and carparking spaces in their place.
Value of Works:
Parkfield £900k
The Hyde £1.2m
