After consultation with the Warsaw-Modlin Airport Board ("Investor"), the General Contractor submitted on Friday 8 February 2013 a proposal concerning the execution of works on the runway to the Investor. The proposal is based on the concept of the POLCONSULT Design Studio, which has been collaborating with the Investor for many years, including preparing the Terms of Reference and Project as well as has cooperated with the General Contractor on the design of the runway surface.
Following the in-depth analysis of the technical solutions used previous on the runway and the further airport operating potential, the General Contractor recommends to renew the runway surface through the milling of the cement concrete pavement and setting the asphalt concrete layer on a steel grid.
The proposal is based on the concept of the POLCONSULT Design Studio, which has been collaborating with the Investor for many years, including preparing the Terms of Reference and Project as well as has cooperated with the General Contractor on the design of the runway surface.
Following the in-depth analysis of the technical solutions used previous on the runway and the further airport operating potential, the General Contractor recommends to renew the runway surface through the milling of the cement concrete pavement and setting the asphalt concrete layer on a steel grid.
The cement concrete surface was set by the General Contractor at the express request of the Investor included in the Functional and Utility Programme.
The recommended option is in line with the decision of Regional Construction Supervision Inspectorate dated 24.01.2013, which requires to remove the defects in the concrete surface structure of the runway. The recommended option provides, inter alia, the following technical parameters:
- The planned number of repetitions, i.e. take-off and landing of aircrafts exceeds the required number of repetitions for the pure concrete surface from a few to tens of per cent (for the cement concrete the repeatability amounts to 380,000).
- Expansion joints are not needed when a solution with the steel grid is used – for concrete pavements joints become degraded and required to be continuous monitoring and filled.
Runway surfaces of asphalt concrete are used successfully at airports in Europe. For instance, the asphalt concrete runway at the Lech Wałęsa Airport in Gdansk, which is in use for 30 years, is the best example of this type of solution in Poland.
In view of public interest, i.e. the promptest traffic re-establishment at the Modlin Airport, the choice of upgrading variant by the Investor should take into account time for work completion on the runway. The proposed technology assures the shortest duration of the works and re-establishment of traffic at the airport within 6-8 weeks from starting works. For comparison, execution of works when using the present technology, without the suggested changes in technology, extends the completion time for about 3 months.
The proposed option of the modernization means both the optimal technological and running solution. It will allow to optimize the costs of maintenance of the runway during the permanent use of the airport. In a long period of time, this means significant savings for the Warsaw-Modlin Airport Company. Surface made of cement concrete is particularly difficult to maintain during the first three years after the concreting. Therefore, for the time of initial use, it is required that the airport maintenance service develop a detailed technology how to proceed over the period of varying temperatures in order to protect the concrete against destruction.
Technical difficulties and costs associated with the maintenance of the ice-covered concrete pavement is one of the decisive factors in favour of using asphalt concrete for airport investments in Europe. The number of losses in concrete runway and no ice-alert warning system at the Modlin Airoprt shows very likely that there was a need for using de-icing
agents of increased, excessive concentration, against the aerodrome standards and guidelines.
The General Contractor commissioned to prepare three independent expert assessments of the impact of chemicals used for de-icing the runway, which prove the reason of arising loose chips and will determine the responsibility of the relevant parties and allow to exact financial consequences.