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 RGL 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. RGL 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 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 RGL Recoilless
Gimbal:
The development of the RGL 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 RGL 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.
