Approach

Object

​Conditions for implementation

​Strengths

​Limitations

​Rational area of application

​Crack injection

​local crack, filtration channel, joint

​access to the injection zone is required

​targeted restoration of watertightness, relatively high process controllability

​dependence of results on crack width, surface roughness, and injection pressure

​local leaks, established filtration paths

​Surface sealing and barrier coatings

​surface of the pressure zone, areas at risk of re-opening

​access to the surface and properly prepared substrate are required

​interception of filtration from the pressure side, protection of large high-risk areas

​high requirements for surface preparation quality

​areas with risk of hydraulic fracturing, zones prone to re-opening

​Direct underwater repair

​damage in the underwater zone

​operations are carried out in a water environment

​no need to take the structure out of operation

​high labor intensity, influence of water on operation quality

​deep or hard-to-access underwater defects

​Repair in a locally dewatered zone

​underwater defect requiring precise substrate preparation

creation of a dry working chamber is required​

​more controlled conditions for material application

​increased complexity of work organization and equipment

​critical underwater areas with high quality requirements

​Use of self-healing waterproof materials

​microcracks, initial damage

​applied during manufacturing, curing, or early repair stages

​reduction of permeability and slowing of defect development

​limited effectiveness for large crack openings

​prevention of microdamage development

​System of early monitoring and targeted intervention

​potentially hazardous zones of the structure

​continuous or periodic monitoring is assumed

​reduction of response time and share of emergency repairs

​depends on organizational and technological support

​operation of long-service-life structures