INSPECH in practice.

The situation

A well-known Dutch airport wanted to know the Pavement Condition Index (PCI) and the residual constructional lifespan of a number of taxiways and platforms. The PCI is an example of a technical approach, which requires a manual examination of the pavement. The index was originally developed by the US Army Corps of Engineers, but was later standardized by the ASTM. The surveying processes and calculation methods are documented and standardized by ASTM for airport roads and sidewalks. Commissioned by NACO Airport Consultancy & Engineering, Unihorn has carried out investigations of the pavement and drafted recommendations. What was special about this project was the way in which the input for the PCI determination was collected. Normally this is done manually but thanks to INSPECH this aspect of the PCI process was automated.

The solution

The current state of the asphalt and concrete pavements were recorded with HD video cameras and defect locations determined by GPS using a specially equipped Unihorn vehicle driven along the taxiways. Subsequently, the observable defects from the video images were identified by INSPECH in accordance with the criteria of the ASTM D5340-20 standard.

To determine the PCI values, Unihorn then built a database in MicroPaver with a section and sample unit layout. After entering the defects, the PCI values were calculated with MicroPaver.

The situation

A-Lanes A15, a partnership between Ballast-Nedam, John Laing and Strukton, has been commissioned by Rijkswaterstaat (Dutch Department of Waterways and Public Works) to widen the A15 between Maasvlakte and Vaanplein within a Design, Build, Finance & Maintain DBFM agreement. The area includes 37 km of highway, the Botlektunnel, the Thomassentunnel and the Botlekbrug.

Every year, A-lanes A15 must demonstrate the contract requirements are met and has to draft an asphalt repair plan annually. Visual inspection is therefore crucial and damages must be recorded according to the visual inspection system of Rijkswaterstaat (the DWW method).

The solution

For this project it was important to be able to inspect OPA8 asphalt concrete. This is a fine and open asphalt concrete with a high percentage of hollow space (25%). As a result, the mixture deviates considerably from the regular open top layers, which meant that INSPECH had to undergo additional training. This was achieved in just a few days which enabled INSPECH to very quickly inspect the A15 as required.

The answer

Thanks to INSPECH, A-Lanes now have a reliable way to assess the condition of the asphalt road surfaces. In previous inspections, carried out by human inspectors, too many inconsistencies in assessment had arisen between different inspectors. Also over the years, the variations in inspection results mean that creating and managing maintenance plans proved difficult.