Hydrodemolition used in Johannesburg bridge rehabilitationPublished 15/11, 2017 at 18:05
Major structural repairs were recently completed to the M1 North highway bridges over Oxford and Federation Roads in Johannesburg, South Africa. The removal of superfluous concrete was made possible by hydrodemolition, carried out by South Africa’s leading water jetting solutions company Total Blasting.
Commissioned by WBHO Construction, in partnership with the South African National Roads Agency, the wider project included the complete rehabilitation of the bridges in Rosebank, involving major structural repairs. Hydrodemolition technology was employed to remove deteriorated concrete from the structures without damaging the existing steel reinforcement.
“Hydrodemolition comprises the use of high-pressure pumps, water and robotics to break down and remove cement-based materials in situ,” said Total Blasting Director, Bradley Storer. “It is a special demolition technique that employs high volume. It can target the specific demolition area with relative precision, which supports a cleaner demolition site. Unlike conventional demolition methods like jackhammering, hydrodemolition does not damage the rebar or surrounding structure.”
Challenges to the hydrodemolition aspect of the project included site access, which was limited due to the nature of the roadworks and construction, as well as channelling sufficient water to site to feed the pumps, which was managed by using multiple road tankers to supply the water.
Technology supplied by Total Blasting for this project was specifically developed for concrete demolition and was imported from Europe and the USA. The bridge rehabilitation project was completed within deadline and a total of three Total Blasting employees, with specialized skills in water jetting and hydrodemolition, were deployed to this project for its duration.
Total Blasting has a track record of four years’ experience in supplying hydrodemolition tools and expertise to the Southern African market and 20 years in water jetting. Selected for its necessary skills, specialized hydrodemolition tools and experience, Total Blasting delivered with its full commitment and attention to detail. “Hydrodemolition is in its infancy in Africa,” said Storer. “The success of this project does not only represent a well-respected client that is highly satisfied with the work we have done, but opens up opportunities for hydrodemolition and water jetting in the southern African concrete repair sector.”