Restoration and Strengthening of Culverts in Olympia Odos

Project description

Location: Elefsina-Patras
Year: 2017-2018

Interventions were necessary to extend the service life of unreinforced and reinforced concrete culverts of Olympia Odos. More specifically, some culverts had only light concrete damages while others required structural strengthening. ENKA undertook the rehabilitation of 40 culverts in segment Elefsina-Corinth and 35 culverts in Egio region. ENKA conducted thorough visual inspections and in cooperation with DENCO Structural Engineering P.C. devised technical reports for the rehabilitation, retrofit, and strengthening design of the culverts along with a complete Working Method Statement (WMS) for the execution of the works, which were approved by Olympia Odos and by the Independent Engineer Setec-Salfo.

Tasks description

The first stage of the project started on January 2017 and included the thorough visual inspection of the culverts and the assessment of the damages and of the structural integrity of the structures from ENKA engineers. The structural condition of the culverts was initially checked by the engineers of ENKA and afterwards, in cooperation with the engineers of DENCO P.C., rated in a 10-grade rating system. A technical report was compiled for each culvert, while for the whole project a general WMS was submitted. The works were completed in spring 2018.

The main works that took place are:

  • Removal of the loose concrete and shoring of the existing culvert where necessary.
  • Cleaning of the corroded reinforcement with sandblasting and application of corrosion inhibitor.
  • Concrete sections rehabilitation with repair mortars R3/R4 (EN 1504-3) or shotcrete.
  • Crack sealing with cement grout injections.
  • Crack sealing with epoxy resin injections.
  • Construction and expansion joints sealing and repair with polyurethane-based sealant.
  • Concrete protection against water ingress with crystalline technology surface applied products by XYPEX.
  • Reinforcement protection with surface applied corrosion inhibitor through impregnation.

For the culverts whose structural integrity was poor (rating < 5/10), structural retrofit designs were devised and the typical interventions that included the construction of a new reinforced concrete culvert (cast in situ or shotcrete) on the interior of the existing structure for its whole length or partially, were performed.

The methods followed, and the materials and systems used were in accordance with relevant standards (mainly EN 1504) and the Greek Technical Guidelines (ΕΤΕΠ).