Self Healing Aspalt on the A58

On this Blog we will give info on the test track with Self Healing Asphalt that is built on the A58 near Vlissingen in The Netherlands. The Asphalt is a special type of ZOAB (very porous aphalt concrete) containing small steelwool fibres. A known but serious problem with ZOAB is ravelling: stones at the surface coming off in time due to microcracking in the binder. The special ZOAB that is developed at Delft University (sponsored by AgentschapNL) can be heated with induction energy due to the fibres that are present which closes the microcracks and with that extends the service life of the road.

Tuesday, 9 August 2011

test results look promising....

Of course you are all waiting to see some results of the laboratory tests that are now being performed on the samples that we took from the road. We do not have final conclusions yet, however, tests show that the service life of the material might increase (a lot).

The results shown below are from the 4-point bending fatigue tests performed in the road engineering lab at Delft Univerity. In this set-up different type of tests are compared.

The first line in the graph at the right is for the reduction in flexural sifttness in the original fatigue test. The next line is if we repeat the fatigue test after a rest period of 18 hours. The third line is for the case if we apply heating to 70 C during the rest period. The heating realy improves the behaviour of the material

In the figure at the right it can be seen that we did do multiple loading cycles where we had rest periods including heating. The material almost recovers completely after each cycle and the total fatigue loading cycles that can be done is much much larger than the test without resting and heating.

Please don't get too exited....We should not conclude yet from this result that the service life of the road will increase in the same manner, however, it looks promissing, doesn't it?

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