A full-scale instrumented test-facility for French rational mechanical airport pavement modeling improvements

As part of a research program on airfield pavement testing and assessment, the STAC has constructed a 1800 m2 full-scale instrumented test facility in Bonneuil-sur-Marne (France).

This test site is aimed at improving the pavement behavior modeling under heavy loading. The advanced mechanical models, when in-situ validated on the test facility, are then to be used to improve for instance the STAC’s rational pavement design method, or the Heavy Weight Deflectometer (HWD) data analysis.

It is also a privileged tool for pavement testing apparatus or methods assessment, providing on the one hand reference structures with well-known layer thicknesses and material characteristics, and on the other hand strain data from embedded sensors.

Finally it can also be used as a reference test site for pavement testing apparatus in-situ verification. It actually features a dynamical precision scale allowing to check the reliability of static or impulse loads, and deep anchors for deflection measurements in-situ verification.

The facility includes the main structures encountered on airport platforms. It actually comprises a flexible pavement, a rigid pavement including dowelled and non-dowelled slab areas, and shoulder structures. All structures, except shoulders, are equipped with embedded pavement instrumentation. Mechanical sensors have been placed at different depths in the pavement in order to measure the critical strains taken into account in the mechanical models used for rational design or pavement testing analysis. Most of these sensors have been developed specifically for this test facility. Temperature profiles have also been set up in both flexible and rigid pavement.

Layer thicknesses are well-known from GPR surveys coupled with corings, and material behaviors have been studied through laboratory testing.

Test surveys performed so far on the facility include, inter alia, HWD tests over instrumented areas of the flexible and rigid pavements, which contributed to validate advanced mechanical models based on dynamical finite elements calculations developed by the STAC. This was achieved by comparing expected time-related strains induced by HWD impulse loads with the in-situ sensors measurements.

The experiment confirmed that the complementarity between theoretical developments and in-situ validation remains a major way to improve pavement behavior understanding.

The STAC also organized in October 2013 the first European HWD round-up on the facility. It gathered 6 HWDs and 2 FWDs from France, Belgium, Switzerland and the Czech Republic.

Force measurements delivered by the different F/HWDs were first checked using the STAC’s dynamical weighing scales. Then multi fall-height crossed tests were performed for each device, first on several reference points of the non instrumented flexible pavement areas and, finally, on the instrumented areas.

All participants expressed much interest in this event. The next sessions should take place once every two years.


Updated 7 Jul. 2014

Video

Strain signals measured under a rolling wheel pass

 

Control of the HWD recorded force signal, using the STAC's dynamic precision scales