A crack is a type of failure whereby fracture lines are formed on the circumference and/or along the length of the piping. Cracks are predominantly formed in rigid pipes and can be a precursor to pipe rupture or breakage. Piping cracks can come in four different forms, longitudinal cracks, lateral cracks, interanglar cracks and cracks originating from a specific point.
Cracks can also occur because of a number of stresses including:
- Hydrogen-induced cracking
- Interangular stress corrosion cracking
- Environmental cracking
Cracking is one of the most common reasons for the need for trenchless rehabilitation.
Trenchlesspedia Explains Cracks
The formation of cracks in pipes is usually a sign that some form of damage has taken place (with the exception of reinforced concrete pipes where cracks may be caused by temperature changes and shrinkage).
The type of crack formed in the pipe is closely connected with its root cause. Therefore, it is possible to diagnose the cause of a crack by assessing its properties such as:
- Crack pattern
- The depth of the crack
- The crack location and
- The rate of progression over time
The main causes for the development of cracks in pipes are:
- Settlement (typically pipes constructed from brittle materials such as clay)
- Damage during transport, storage, installation, backfilling or maintenance
- Excessive wear and corrosion.