BE-13 Renovation: Lining with Cured-In-Place Pipes - F...

Final Work, Acceptance, Renovation Defects

Quality Influences during Installation of the Lining Tube

Quality influences during installation are mainly caused by deviations in the process parameters to be observed (e.g. curing temperature and temperature profile, light intensity, inflation pressure, contact pressure, etc.). If the material parameters specified in the manufacturer's specifications or by initial or suitability testing are not achieved, the cause is often insufficient contact pressure of the lining tube against the host pipe wall or incomplete curing of the resin matrix. 

The table provides an overview.

Table: 

Quality influences during installation [MUNLV05]

Load-bearing capacity Tightness Functionality
- Incipient resin reaction due to influences during transport causes installation difficulties and curing problems
- Insufficient installation pressure may cause longitudinal folds
- Insufficient installation pressure leads to wall thicknesses exceeding the static proof and/or air pockets in the composite
- Excessive installation pressure leads to wall thickness reductions (compared to static proof), E-modulus too high
- Curing disturbances (moisture, temperature, dirt, delays, etc.) reduce the static properties (E-modulus, air pockets in the laminate). Properties (modulus of elasticity, flexural strength)
- Too low installation pressure causes air pockets in the composite and reduces water impermeability
- Strong styrene boiling/evaporation during curing causes air pockets in the composite
- Excessive thermally induced positional changes during cooling lead to overstressing of the connections
- Excessive elongation during installation causes seam breakage
- Too high inversion speed causes air inclusions
- Milling error when opening a lateral connection
- Missing/insufficient connection of lateral pipes and manhole structures
- Disturbance during the pulling-in process causes radial wrinkles
- Fluctuating installation pressure may cause the internal membrane / coating  to peel off prior the resin reaction
- Excessive length shrinkage due to temperature change (drilled out too early) leads to partial covering of the connection opening of the side inlets

 

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