NMC PLC: Brush Traction Ltd, Loughborough

Scope of work

Removal of internal floor slab 40 lin metre long x 15 lin metre wide x 2400mm thick to allow new machine foundations to be formed. Due to ultra delicate in-use engineering equipment sitting on the slab which was operating on a 24/7 basis, Hi Tec Diamond Drilling Ltd carried out the slab removal by vibration free diamond floor saw cutting and stitch drilling methods.

The works required on site consisted of forming a perimeter break line x 500mm deep in to the r/c floor slab, this was carried out with the use of a diesel powered floor saw fitted with a 1200mm dia wet cut diamond saw blade. 415v high frequency and hydraulic powered drilling rigs with attached 150mm dia wet cut diamond core bits were used to carry out the stitch drilling works vertically through the r/c slab.

Due to limited access, working space, and factory headroom the centre section of slab had to be stitch drilled into sections varying from 1000mm x 1000mm up to 1750mm x 1750mm, each piece weighing up to 13 tons each. Upon completion of the stitch drilling works each slab section to be removed had 3no 40mm dia x 500mm deep angled lifting holes drilled, lifting bolts were bonded in to each hole with epoxy resin as to allow removal at a later date by the client with the use of the on site overhead crane.