Final Work, Acceptance, Renovation Defects
Measures to Safeguard the Placing Decision
Table:
Measures to safeguard the placing decision [MUNLV05]
References of the contractor |
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- Name the contractor's most recent renovations. Obtain evaluations from other network operators.
- Test results of CIPP liner samples from recent site tests.
- Designate procedures for reconnecting laterals and manhole.
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Require suitability tests from the contractor |
- Disclosure of the delivery conditions of the lining tube and its characteristic properties, e.g.: Long-term E-modulus, ring stiffness, high-pressure flushing resistance, chemical resistance, abrasion resistance, water impermeability after milling the internal membrane.
- Request the procedure manual / a construction site documentation with target values according to the liner manufacturer's specifications, e.g. target heating curve, max. permissible inversion speed and max. tensile force.
- This also applies to subcontractors (e.g. for the integration of connection lines).
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Demand of identification proofs |
- Handing over certificates and samples of the resin system used, the carrier material and the fillers before the rehabilitation measure (comparative sample).
- Identification test if necessary when deviations are suspected (proof of compliance with comparative sample). To be on the safe side, always take a pure resin sample on site from the installed liner material
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Comparative product testing |
- Exchange of experience with other network operators on the qualification of contractors.
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Public call for tenders / restricted invitation to tender |
- Summary of the requirements for the quality of materials and processes as well as the performance, reliability and competence of the bidder already in the invitation to tender in order to make the placing decision on the basis of a performance competition.
- In addition to specifying limit values for the material (e.g. ring stiffness, modulus of elasticity, abrasion, etc.), also specify limit values for the geometry of the CIPP liner (e.g. wall thickness, annular gap, pre-deformation, etc.) and, as far as possible, check them on the construction site and during the condition assessment.
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