Localised Repair Techniques.
Localised Repair Systems are used to address point service problems or individual structural defects within a pipeline as opposed to full manhole-manhole rehabilitation.
The methods of localised repairs can be grouped as stabilisation or structural repair systems.
In general, a stabilisation technique will address a localised problem, such as infiltration, without adding to the structural integrity of the pipeline.
Typically, stabilisation techniques include chemical stabilisation/flood grouting, joint sealing/resin injection, mechanical seals although in some circumstances the latter can also be classed as a structural repair.
By definition, a defect addressed by a structural repair method will improve the structural integrity of a pipeline. Generally structural repair techniques include CIPP patch repair (usually ambient cure), robotic repairs.
Pipe re-rounding may be utilised as part of a localised repair operation to ensure that the repair maximises the potential flow capacity of the pipeline. In pipes which are misshapen but where there are no cracks or fractures re-rounding may in itself be utilised as a localised repair technique. Lateral repair at the lateral/main junction may also be viewed as a localised repair if the repair is only taking place at the pipe intersections using some of the above techniques or using a Lateral Connection Sealing operation or Top Hat installation.
Localised Repair Techniques usually take less time on site, require less equipment, cause minimal disruption to the locality, require less man-power, have a smaller site footprint and cost less than full manhole-manhole rehabilitation. However, they will only act at the point of the defect meaning that other areas of the pipe remain exposed to the influences that may have caused the initial defect.
This may in turn mean further work will be required on the pipe at some later stage, which in turn may require more regular monitoring of the pipeline.