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.

Thursday, 6 December 2012

TEDxDelft talk Erik is online

The TEDxDelft talk that Erik gave in October is now online.
You can watch it on:
or you can go directly to YOUTUBE

PLSE 2012

Yesterday Erik gave an invited presentation at the PLSE-2012 conference in Hong Kong on self healing concrete an asphalt.

Sunday, 14 October 2012


This is how "De Jongens Van De Tekeningen" saw the presentation from Erik at TEDxDelft:

Saturday, 6 October 2012

Erik performs at TEDx Delft

Yesterday Erik gave a presentation on self healing asphalt at TEDx-Delft.

You can watch the presentation on the TEDx-Delft page.

Wednesday, 1 August 2012

PhD defence of Quantao Liu

Quantao Liu will defend his PhD-thesis on October 2nd, 2012 at 10:00 am in the Aula of Delft University.
The title of his thesis is: "Induction Healing of Porous Asphalt Concrete".
After the PhD-defence you can download the pdf-version of the thesis from this BLOG.
Click here to get the PhD-Thesis.

Interview on BNR newsradio (in Dutch)

A few weeks ago Gerbert van Bochove (Breijn-Heijmans) and Martin van der Ven (Delft University) were interviewed bij BNR newsradio (in Dutch) about the development of our self healing asphalt. A new test section is prepared by Heijmans in Tilburg (Netherlands), which is explained in the interview.
You can listen at the recording at the BNR-website.

Monday, 16 April 2012

Monday, 27 February 2012

Webinar Selfhealing concrete and asphalt

Today Erik gave a Webinar on Self Healing Concrete and Asphalt for Betonica.

You can watch back the webinar on the website of Betonica.

The presentation you can download here.

Friday, 3 February 2012

TRB conference Washington DC

Last week Quantao, Erik and Martin visited the anual TRB meeting in Washington DC and presented our concept of self healing asphalt. The article will be published in the TRB publication and a link will be placed on this site soon.

Monday, 24 October 2011

Strength Recovery Tests

Last week Quantao performed some strength recovery tests of beams on an elastic foundation.
The set up used for these tests is given below.

The test procedure consists of breaking the notched beam on the elastic foundation, heating the fractured beam, resting the heated beam for 6 hours and finally breaking the healed beam again.

The healing index is defined as the original strength divided by the healed strength).


The fractured beam showing the two fracture surfaces at the location of the notch is given below.

 Next figure shows typical loading curves of original beam and healed beam (different heating temperatures)

 The strength recovery ratios are presenteed in the next figure.

The fractured beam cannot heal the crack by itself at 5°C and 20 °C: the crack is too big to be healed by natural healing. Induction heating can heal the crack and the extent of healing depends on the heating temperature. The optimal heating temperature is 85°C to obtain highest strength recovery. Further heating causes binder drainage and swelling problems, which offsets the healing benefit.

Tuesday, 18 October 2011

Testing Different Coils

Last week we spend together with our partner SGS-Intron a day at the producer of the induction machine that we are using to heat and heal the asphalt. We once again found out that the mechanism of induction heating is influenced by many factors. To find the right combination of fibres in the material (length, cross section, amount, distribution) and settings of the machine (frequency, power, coil design etc) needs some insight knowledge, but also some trial and error.
We can not say that we had nothing to choose from..............

Wednesday, 5 October 2011

Breijn Symposium

Breijn is organising a symposium series this month about "Flexibilitiet in Levensduur"
Erik gave a presentation on Self Healing Materials yesterday. Last week Prof Sybrand van der Zwaag of Aerospace Engineering  of TU Delft was the guest speaker and next week Prof Andre de Boer from TU Twente will take the floor. More info on the symposium can be found on the Breijn-website.

Main topic of the presentation was Self Healing Concrete and Asphalt.
The Self Healing Asphalt part was dealing with the subject on this blog.
More info on the Self Healing Concrete projects can be found on

At the end of the symposium all participants received the Self Healing Breijn-Cube. Guess what kind of material this is?.....

Wednesday, 28 September 2011

more results from tests

Quantao obtained in the last weeks some new interesting data from the tests.
The tests that he performed are the 4-point bending fatigue tests on beams. See one of the posts below for the set-up. What comes out of the tests is that the optimum healing temperature is 85 C. The tests are done on 'fresh' samples and samples that are artificially aged to an age of about 5 years. The healing performance and fatigue life extension ratio of the fresh and aged samples is almost equal. In the aged samples we see a slight decrease of 2%.

In the graph below the fatigue life extension ratio is plotted for tests were we only had natural healing (just rest periods) and were we had our induction healing combined with rest periods.

Sunday, 11 September 2011

RTL4 news item

RTL4 news had yesterday an item on road damage on Dutch highways. Self Healing Asphalt with steelwool was proposed as a possible solution. In the video you see some shots from the project in our lab.
RTL4 is a commercial TV station, which means you first have to watch a commercial before the video starts. Sorry about that.....

Friday, 2 September 2011

Microscopy and Nano-Indentation

To measure the properties of our self healing asphalt we are doing a lot of different tests. These tests are performed on the virgin material, the aged material (after oxidation) and on the the damaged and subsequently healed material (after applying the induction healing).
We are applying also some new techniques, like microscopy on thin slices of 30 micrometer thick. See the image on the left.
Another technique we are using is nano-indentation on polished samples (image on right side). The indents are performed using a berkovich tip and a cooling stage at a temperature of -20 C with our Agilent G200 Nano Indenter.

Thursday, 1 September 2011

Very Nice Self Healing Product

If you are interested in other self healing products you should have a look at the video below. This is realy incredible!. It would be nice if our asphalt would perform in a similar way......

Sunday, 14 August 2011

Self Healing Concrete BLOG

We are proud to announce that we also created a BLOG for Self Healing Concrete.

If you want to find out more, have a look at:

Tuesday, 9 August 2011

Article in NRC 30/31 July

Another article discussing our project was recently published in NRC Handelsblad on July 30/31.

2nd edition of Self Healing Materials brochure

AgentschapNL published a new version of the Self Healing Materials booklet. You can download it by clicking on the image. Happy reading!

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?

article on project in Nederlands Dagblad

On August 4 the Nederlands Dagblad published an article in Dutch with the title
"The ideal asphalt does not exist yet" (but we are getting close....).

Monday, 8 August 2011

self healing conference ... continued

The extended abstract of the presentation can be downloaded here: Schlangen_Extended_Abstract_BATH

and the powerpoint slides of the presentation can be found here: Schlangen_Presentation_Bath

Self Healing Conference Bath

End of June we had a very interesting conference in Bath UK about self healing materials.
A lot of new research was presented and many good ideas for furthure work were proposed.
Below you see all the participants:

Erik presented the work on the self healing road. It turned out that this was one of the first real application (and maybe the only one...) of a civil engineering self healing material.