The technique of cutting/removing concrete from a structure by the use of a high pressure water jet. A simple definition for what has now become a very specialised sector of the water jetting industry of which Rentajet are the acknowledged leaders!
By using high pressure water, the integrity of the original structure can be maintained. Hydrodemolition is now recognised by Structural Engineers and Consultants as the safest, most effective, vibration free method of concrete because the parent material suffers no cracking and reinforcing steel can be retained undamaged by the process.

Technical Advantages

	Does not cause micro or macro cracks in the structure.
	Does not damage reinforcing steel or loosening within the structure.
	Reinforcing Steel is cleaned by the action of the high pressure water enabling a superior bond with new concrete.
	Hydrodemolition produces a superior surface bond for new concrete in comparison with conventional methods.
	A proven performance specification can be achieved because selective removal is achieved in relation to the strength

           of the concrete.

Safety Benefits

	Reduces the potential for injury to operators due to vibration and heavy lifting.
	Dust pollution is eliminated.

Commercial Benefits

Hydrodemolition can be faster than conventional jack hammering and can result in shorter possession times and reduced

           traffic disruption on structures such as bridges.

Equipment Specifications

Hydrodemolition is undertaken using Hand Held Safety Guns, Gimbal Mounted Lances and Robotic Rigs. High pressure water is provided by High Pressure Pumps having an output range from 20 litres/minute to 250 litres/minute and pressures to 3000 bar. Rentajet will provide the most suitable equipment relevant to the type of work. Factors that influence this choice will be: Access - Amount of concrete to be removed - Time Available - Water supplies available - Environmental factors.

Technical Support

Consulting Engineers and Estimators are always interested to establish precise work rates that may be achieved. With our practical understanding of site requirements we can provide detailed advice on all aspects that influence work rates together with Method Statements and Task Risk Assessments.

	The Hand Held Safety Gun
	The Rentajet Recoilless Gimbal
	Computer Controlled Concrete Cutting

	The Hand Held Safety Gun: The technique of cutting concrete with hand held safety gun has evolved over the past fifteen years. Rentajet now provide a wide range of options depending on specific site requirements and these include the following:- Standard Safety Dump Gun for heavy duty work and operating pressures over 1200 bar. Electro-Pneumatic Safety Gun for precision work at pressures to 1500 bar. Lightweight Electro-Pneumatic Safety Gun capable of operating at pressures to 3000 bar for specialist applications such as concrete cutting for inspection/survey work. Applications Small individual patches of concrete removal. Restricted/difficult access. Precision cutting work.
	The Rentajet Recoilless Gimbal: The development of the Rentajet Recoilless Gimbal has enabled operators to manually control the full potential of Jetting Units up to 220kW. Accuracy to +/-mm can be maintained and removal rates are far in excess of those achievable with the hand held safety gun. The Rentajet Recoilless Gimbal incorporates a positive lock barrel length adjustment for safe control of stand off distance. Risks associated with high nozzle reaction forces are minimised. On/Off control of water pressure is achieved by an electro-pneumatic trigger which is a major factor in the reduction of operator fatigue. Applications For high production rates in conditions where manual control is specified or limited access is available.
Computer Controlled Concrete Cutting: The Computer Controlled Hydrodemolition Rig is hydraulically driven and fully enclosed. It is ideal for mass removal of concrete and for use with Jetting Units up to 450kw. Setting up time is kept to a minimum and accurate control over depth and width of cut is a feature of this system. The design of the Hydrodemolition Rig ensures that high removal rates are maintained over long periods and risk to operators is minimised. The rig can be used on horizontal or vertical surfaces.
Holesmouth Bridge - Avonmouth 650mm full depth deck removal was achieved by using a combination of Hydrodemolition Rig coupled to a 450Kw jetting unit and a Gimbal assembly coupled to a  220Kw jetting unit.
For more information contact us at sales@rentajet.co.uk