Serious London Cutting from Dymatec

Published: 22/10, 2018

Two of the UK’s biggest players in the diamond drilling and concrete have recently removed a 5,232 yd3 (4,000m3) slab of concrete from a building in London. The job took 14 months, involved 10,000t of concrete, and required 1,000 diamond blades and cores. 

The Grosvenor Place demolition project was located a stone’s throw from Buckingham Palace in London. The project involved the removal of a basement slab of a five-story building in one of the most prestigious addresses in the capital so as to allow for additional below-ground construction to convert a property into a new private hospital. 

This was no easy task, especially given the thickness of the concrete, and the need to retain the majority of the slab to support the building. Undertaking this significant challenge saw two of the UK’s leading players in the diamond drilling and concrete cutting industries, Dymatec and London Diamond Drilling, combine forces. Dymatec, a supplier and manufacturer of diamond consumables, was retained as the exclusive supplier to the contractor London Diamond Drilling, advising on, and providing, all the blades and cores needed to complete the works., 

 The project plan was to remove a 26-ft (8m) wide section around the entire perimeter of the basement slab. The perimeter had to be removed in sections to allow for the construction of steel structural support needed to hold up the main facade, which was to remain intact. The concrete slab varyied in thickness from 3.3 ft to 11.5 ft (1m to 3.5m), with a significant quantity of 1.25 in (32mm) rebar throughout. 

As well as being a significant quantity to remove 5,232 ft3 (4,000m3) of concrete, the material was also packed with dense black flint, making it extremely hard. This meant that only the fastest diamond cores and blades would be able to power through it. To tackle this tough, unrelenting concrete, Dymatec recommended the SDF P20 diamond blade and supplied more than 70 of these blades in varying sizes during the project. This powerful high performing blade, manufactured solely by Dymatec, was the only solution to combat the challenging concrete. 

The plan was to tracksaw the entire perimeter up to 3.6 ft (1.1m) deep, and cross cuts into sections. However, this was only possible where the concrete was shallow enough. Anything deeper than 3 ft (1m) had to be stitch drilled. To facilitate this process, Dymatec supplied over 900 Turbo S cores. Once the perimeter of the concrete slab had been removed, the slab was peppered with 8.3-in (212mm) diameter holes so it could be broken up using an 8-in (203mm) hydraulic burster. Only when this was complete could a team come in and break up the slab using Brokk 500 and 260 remote control machines. 

During the 14 months it took to cut and drill the basement slab, Dymatec was on site at least once a week, collecting used cores and blades, returning them to its UK headquarters to retip and repair, before delivering new and refurbished consumables back to the project. In addition, Dymatec’s sales manager David Hibbert visited the project once every two weeks, to ensure the products were performing as they should.  To ensure that the project stayed on schedule, and that tracksawing stayed ahead of the steelworks team, London Diamond Drilling was on site most every day during this demanding project.

Work has now started on casting the new concrete slab for Grosvenor Place, with the construction of the new building expected to last a couple of years.