Demolition is a critical part of the construction cycle
March 30, 2021
When a layperson considers ‘demolition’, it is automatically equated with ‘blowing up’ buildings. However, demolition is a highly structured and technically complex process from an engineering, logistical and health and safety perspective. As a critical part of the construction cycle, it is not only reserved for structures and facilities that have reached their end of life. Demolition creates space for improvements, facility upgrades or even more beneficial land use. In some instances, it is often necessary to improve the safety profile of a facility.
Ageing structures may require significant investment in terms or resources with regard to maintenance – resources that would generally have been available for ongoing operations. In addition, ageing structures may quickly become hazardous, adding more risk to redundant facilities. As such, demolition is a critical part of the lifecycle of most facilities, highlights Jet Demolition Contracts Manager Kate Bester (NDip Civil Engineering – PMP).
“Our approach to demolition projects has always been from the point of view of adhering to international best practice,” comments Bester. Wherever possible, mechanical methods are selected to demolish structures due to the improved safety profile offered. Here specialised demolition excavators equipped with highly-specialised demolition tools that are not commercially available in South Africa are deployed.
Jet Demolition’s collection of tools ranges from hydraulic hammers, shears and grapples, to grinding wheels, pulverisers and crushers. It also has a few specialised tools developed in-house to suit specific on-site applications. Its smallest demolition machine weighs only 1.4 tonnes, whereas the largest is over 102 tonnes.
“What makes our fleet unique is the fact that not only do we own it, it is maintained by our own in-house plant department,” notes Bester. What is more, equipment is traded at very low hours. While it is not uncommon for general construction equipment to be traded after 10 000 hours, Jet Demolition’s fleet is generally traded at half that time.
When do explosives come into play during the demolition process? It depends on determining the single method best suited to the project at hand. In some instances, explosives will be called for. For example, the 108-m-high, 31-storey Bank of Lisbon building in central Johannesburg Central is the tallest steel reinforced concrete-frame building ever imploded by Jet Demolition. A total of 914 kg of conventional mining and civil engineering explosive was used in the implosion on 24 November 2019, with 2 363 separate charges individually timed and perfectly sequenced in accordance with the implosion design.
“Typically, we will only consider explosive demolition techniques in areas where mechanical methods are not appropriate, or where the confines of the site do not allow for alternative approaches,” notes Bester. Controlled implosion was opted for at the Bank of Lisbon in particular because the building had been damaged in a previous fire, which raised safety concerns about the integrity of the structure.
All explosive demolition projects undertaken are designed and directly managed by Managing Director Joe Brinkmann, who has over 30 years’ detailed blasting and explosive experience. This has allowed Jet Demolition to safely and successfully carry out some of the most challenging explosive demolition work ever undertaken globally.
It also points to what continues to give the demolition specialist the leading edge in the market. Internationally, it is uncommon for a single service provider to undertake such a range of projects. Companies tend to specialise in a specific type of project, whether controlled implosions, rehabilitation projects or asbestos abatement, for example.
It is uncommon to find companies capable of carrying out controlled implosions as well as large-scale industrial demolition projects, mainly due to the different approaches required. Even though Jet Demolition offers a range of services, these are not only closely inter-related but complementary. “We have taken a long-term view of our business, specialising in technically demanding, large-scale commercial and heavy industrial projects suited to our range of expertise,” emphasises Bester.
This business strategy was certainly vindicated when Jet Demolition was crowned ‘Best of the Best’ at the World Demolition Awards (WDA) 2020, in addition to winning the Explosive Demolition category, in an online awards ceremony on 12 November last year. It saw the South African company beat top global competitors from the US, Canada and Australia.
Despite acknowledging this as its crowning achievement to date, Bester elaborates: “Every single time we set a particularly challenging structure safely to ground, that same feeling of elation is shared by our teams and clients. Demolition is an industry that is very difficult to compare to any other – every day has the potential to be the best you’ve ever had, whether it involves receiving an international award, or just a pat on the back from a client who witnessed a tricky directional drop.”
The Covid-19 pandemic has had a major impact on what is a very ‘hands-on’ industry due to the nature of the work undertaken, in direct contrast to the social distancing and related regulations now mandatory in construction and related sectors. There is a concerted international drive to embrace remote-working and automated systems to limit the number of personnel directly interfacing with one another.
“Although there are significant developments in industry-specific equipment to promote a more automated approach, we are a long way off from replacing experienced and skilled industry professionals. There is a definite shift to embracing assorted digital and technological tools, for example conducting virtual site visits, but these tools are only able to enhance current work practices, not necessarily to replace them,” concludes Bester.