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The Concrete Times 2017-08.pdf

The CONCRETE Times ŭTVNNFS )ZESPEFNPMJUJPO"OPUIFS8BZ5P$VU $PODSFUF6TJOH5IF1PXFS0G8BUFS Rebars left intact to maintain strength of the floor and surrounding walls Concrete has been used to make some of the most iconic, strong and longlasting structures in the world. However, nothing lasts forever – not even concrete. Exposure to the elements, the passage of time, and repeated use all have their effect. Built to last – the Pantheon in Rome (126 AD) is ample proof of its longevity, built with a form of concrete, so repairing and altering concrete structures is no easy feat. Traditionally, this task was tackled using cutting and demoition hammers. However, an increasing number of people are now turning to hydrodemolition thanks to its environmental and cost-effective properties. For jobs that require a safe and quick method of cutting through concrete, hydrodemolition technology, first used in the 1970’s utilises high-pressure water to remove deteriorated and sound concrete. This process provides an sound bonding surface for repair material and new coating applications. First developed in Europe this technology has become widely accepted for concrete removal and surface preparation throughout Europe and North America. Hydrodemolition can be used to complete a myriad of jobs its central purpose is to remove, cut and scabble concrete. Yorkshirebased hydrodemolition company Hydroblast are frequently tasked with completing specialist projects using these methods. Hydroblast were contacted by a construction company after contractors found themselves needing to install a duct under the concrete floor of a shop as part of the work. When they began breaking the concrete floor themselves, they discovered that the floor was heavily reinforced with a large quantity of rebar. The rebar not only ran through the flooring but also had connections to the walls, and any damage could therefore spread to these areas and could possibly be detrimental to the building. The project required a method that would leave the supports intact, and the project manager therefore advised workers to use hydrodemolition as a method to cut away the concrete. Before starting, Hydroblast identified with the construction team the areas that required cutting by using a concrete cutting saw a saw to lightly cut lines in the concrete to indicate the area for removal. All that Hydroblast required from the site was a regular water supply. Using a hand lance and ultra-highpressure water jet, Hydroblast cut the concrete with minimal noise, no vibrations, and no cracking. The task was completed in one day too so that the construction team could continue working towards their deadlines. Using the Siltbuster HD, Hydroblast were able to clean any wastewater – when the water leaves the hydrodemolition machine it has a pH of 7, which is neutral. But when the water makes contact with the concrete surface, this pH level rises to 10/11, which is alkaline, and the water fills with dust and other pieces of debris. Before this wastewater is returned to the environment, the Siltbuster HD is used to clean and restore the neutral pH of the water. This mechanism uses CO2 to separate any solid particles from water. ):%30%&.0-*5*0/


The Concrete Times 2017-08.pdf
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