Agilis

Agilis – Fatigue Testing on an Airport Drainage Channel

Objectives :

Agilis commissioned Ifsttar to assess the fatigue resistance of a drainage channel made from concrete containing steel fibers. This type of drainage channel is intended for aircraft parking areas at airports. The objective is to reduce, or even eliminate, the conventional reinforcement required for non-fiber-reinforced concrete. This would enable such drainage channels to be cast more quickly using a slipform paving machine, which is currently not possible due to the space occupied by the reinforcement. The specifications require the drainage channel to withstand 100,000 cycles under a vertical load of 260 kN and a horizontal load of 150 kN, applied over the footprint area of an A3 aircraft tire.

Simulation :

The simulation clearly shows the concentration of stresses during aircraft braking at the inner edge of the drainage channel. This area will be closely monitored and instrumented with a strain gauge.

Loading Prototype :

To reproduce the braking loads in the laboratory (one vertical load + one horizontal load), we initially designed a first loading prototype capable of testing two areas simultaneously, opposite each other. However, this type of loading increases the stresses at the bottom of the drainage channel..

We therefore modified the setup by adding a horizontal hydraulic actuator. :

Structure Installation :

A full-scale section of the drainage channel was manufactured under real industrial conditions by Agilis in the laboratory’s test hall and then instrumented. The section was placed on an elastomer representing the ground, and the cyclic loads were applied by two hydraulic actuators installed on the test rig..

Final Loading Setup

Conclusion :

The tests carried out in this study confirm the good performance of the drainage channel subjected to 80,000 cycles under a constant vertical load of 260 kN and a cyclic horizontal load ranging from 10 to 150 kN, applied over an A3 aircraft tire footprint area, with conventional concrete and reinforcement replaced by fiber-reinforced concrete.

Furthermore, the test conditions adopted in this study can be considered particularly severe for the following two reasons :

For all these reasons, the project is considered validated in terms of drainage channel geometry, soil bearing capacity, loading conditions, and concrete mix design (dosage and fiber type).