Use in Surface Preparation
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Traditionally, surface preparation is being carried out using sand blasting, grid blasting, chipping,
etc. As these methods are environmentally sensitive, the use of hydroblasting has become an
alternate method. Visually, the hydroblasted surface is much different from the other surface
produced by the use of traditional methods. Hydroblasting can be applied on variety of surfaces to
remove surface materials like mastic, rubber, curing compound, releasing agents, bond breakers,
leveling compounds, paint, thermoplastics, epoxy, etc.
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In hydroblasting, aggregate and cementious components of concrete are seprated by destroying
the bonding of cement with the aggregate, and finally the aggregate remains intact within the
concrete. Significant improvement in bond strength is obtained using the Hydordemolition
method. The quality of the surface preparation ensures the long-term success and durability.
Using in Concrete Repair
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For repairing the concrete, it is necessary to remove the deteriorated concrete and prepare the
surface. It is also necessary to clean the reinforcement
steel and embedded items before restoration is done.
Hydrodemolition method can be used for this purpose at
ease expediting the repair project.
Merits & demerits
General
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water is the main element utilized in this method which is
easily available.
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Minimal contamination to surrounding area.
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No damage to the reinforcement steel and embedded
materials.
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Minimal dust and noise pollution.
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High capital experience operators are required.
Creates fatigue to the operator within short period and requires frequent rotation of operators.
For Surface preparation:
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No vibration on the structure.
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Can be used in any type of structures either indoor or outdoor demolition.
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Removes any type of deposits, scale, hulls, coatings, soluble salts and oils from the surface.
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Contaminant free surface after preparation.
The sensitive areas such as welding and connection joints are not damaged.
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†
? Causes flash rusting in steel structures.
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Safety
? Hydrodemolition is a clean process which does not produce silica dust during the demolition work £
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and provide healthier work environment. However, the fragments of removed debris fly in all
Š
direction at high velocity during this operation causing hazard at the demolition area. So, it is
necessary to shield the area with proper barriers.
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As this method used high pressure water jets which is very dangerous and can cause serious £
injury and death, if it is not handled property. The operators should wear special protective outfit P
fully covering their body to get protected from the flying debris. To handle the high water ò
pressure during demolition, well trained and technically competent operators should be involved £
÷
this operation.
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Reference
? Field Guide to Concrete Repair application procedures - Concrete Removal using
Hydrodemolition published by American Concrete Institute. ACI RAP Buletin 14.
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