Concrete hydrodemolition technology used in Johannesburg bridge rehabilitation
Major structural repairs to the M1 North highway bridges over Oxford and Federation Roads in Johannesburg were recently completed. The removal of superfluous concrete in preparation was made possible through hydrodemolition, which was successfully undertaken by Total Blasting, South Africa’s leading water jetting solutions company.
Commissioned by WBHO Construction (Pty) Ltd, in partnership with the South African National Roads Agency SOC Limited, 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 any damage to existing steel reinforcement.
Total Blasting Director, Bradley Storer says, “Hydrodemolition comprises the use of high pressure pumps, water and robotics to break down and remove cement-based materials in situ. 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 channeling sufficient water to site in order to feed the pumps, which was managed by using multiple road tankers to carry 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 boasts 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; 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,” Storer concludes.