A "self-healing" asphalt
-
0:37 - 0:40(Hammer)
-
0:43 - 0:47(Laughter)
-
1:04 - 1:10(Microwave beeps) (Laughter)
-
1:16 - 1:18You probably all agree with me
-
1:18 - 1:20that this is a very nice road.
-
1:20 - 1:23It's made of asphalt,
-
1:23 - 1:26and asphalt is a very nice material to drive on,
-
1:26 - 1:30but not always, especially not on these days as today,
-
1:30 - 1:32when it's raining a lot.
-
1:32 - 1:35Then you can have a lot of splash water in the asphalt.
-
1:35 - 1:37And especially if you then ride with your bicycle,
-
1:37 - 1:41and pass these cars, then that's not very nice.
-
1:41 - 1:44Also, asphalt can create a lot of noise.
-
1:44 - 1:46It's a noisy material,
-
1:46 - 1:48and if we produce roads like in the Netherlands,
-
1:48 - 1:52very close to cities, then we would like a silent road.
-
1:52 - 1:56The solution for that is to make roads
-
1:56 - 1:58out of porous asphalt.
-
1:58 - 2:00Porous asphalt, a material that we use now
-
2:00 - 2:03in most of the highways in the Netherlands,
-
2:03 - 2:06it has pores and water can just rain through it,
-
2:06 - 2:09so all the rainwater will flow away to the sides,
-
2:09 - 2:11and you have a road that's easy to drive on,
-
2:11 - 2:13so no splash water anymore.
-
2:13 - 2:16Also the noise will disappear in these pores.
-
2:16 - 2:19Because it's very hollow, all the noise will disappear,
-
2:19 - 2:22so it's a very silent road.
-
2:22 - 2:25It also has disadvantages, of course,
-
2:25 - 2:30and the disadvantage of this road is that raveling can occur.
-
2:30 - 2:33What is raveling? You see that in this road
-
2:33 - 2:35that the stones at the surface come off.
-
2:35 - 2:40First you get one stone, then several more,
-
2:40 - 2:42and more and more and more and more,
-
2:42 - 2:46and then they -- well, I will not do that. (Laughter)
-
2:46 - 2:49But they can damage your windshield,
-
2:49 - 2:50so you're not happy with that.
-
2:50 - 2:54And finally, this raveling can also lead to more and more damage.
-
2:54 - 2:57Sometimes you can create potholes with that.
-
2:57 - 3:01Ha. He's ready.
-
3:01 - 3:04Potholes, of course, that can become a problem,
-
3:04 - 3:06but we have a solution.
-
3:06 - 3:09Here you see actually how the damage appears in this material.
-
3:09 - 3:11It's a porous asphalt, like I said, so you have only
-
3:11 - 3:14a small amount of binder between the stones.
-
3:14 - 3:17Due to weathering, due to U.V. light, due to oxidation,
-
3:17 - 3:20this binder, this bitumen,
-
3:20 - 3:23the glue between the aggregates is going to shrink,
-
3:23 - 3:25and if it shrinks, it gets micro-cracks,
-
3:25 - 3:26and it delaminates from the aggregates.
-
3:26 - 3:29Then if you drive over the road, you take out the aggregates --
-
3:29 - 3:32what we just saw here.
-
3:32 - 3:36To solve this problem, we thought of self-healing materials.
-
3:36 - 3:38If we can make this material self-healing,
-
3:38 - 3:41then probably we have a solution.
-
3:41 - 3:46So what we can do is use steel wool just to clean pans,
-
3:46 - 3:50and the steel wool we can cut in very small pieces,
-
3:50 - 3:53and these very small pieces we can mix to the bitumen.
-
3:53 - 3:55So then you have asphalt
-
3:55 - 3:58with very small pieces of steel wool in it.
-
3:58 - 4:01Then you need a machine, like you see here,
-
4:01 - 4:04that you can use for cooking -- an induction machine.
-
4:04 - 4:08Induction can heat, especially steel; it's very good at that.
-
4:08 - 4:11Then what you do is you heat up the steel,
-
4:11 - 4:12you melt the bitumen,
-
4:12 - 4:15and the bitumen will flow into these micro-cracks,
-
4:15 - 4:18and the stones are again fixed to the surface.
-
4:18 - 4:22Today I use a microwave because I cannot take
-
4:22 - 4:24the big induction machine here onstage.
-
4:24 - 4:27So a microwave is a similar system.
-
4:27 - 4:31So I put the specimen in, which I'm now going to take out
-
4:31 - 4:34to see what happened.
-
4:34 - 4:37So this is the specimen coming out now.
-
4:37 - 4:41So I said we have such an industrial machine in the lab
-
4:41 - 4:43to heat up the specimens.
-
4:43 - 4:45We tested a lot of specimens there,
-
4:45 - 4:49and then the government, they actually saw our results,
-
4:49 - 4:53and they thought, "Well, that's very interesting. We have to try that."
-
4:53 - 4:55So they donated to us a piece of highway,
-
4:55 - 4:58400 meters of the A58, where we had to make
-
4:58 - 5:01a test track to test this material.
-
5:01 - 5:04So that's what we did here. You see where we were making the test road,
-
5:04 - 5:09and then of course this road will last several years
-
5:09 - 5:12without any damage. That's what we know from practice.
-
5:12 - 5:15So we took a lot of samples from this road
-
5:15 - 5:17and we tested them in the lab.
-
5:17 - 5:20So we did aging on the samples,
-
5:20 - 5:24did a lot of loading on it, healed them with our induction machine,
-
5:24 - 5:27and healed them and tested them again.
-
5:27 - 5:28Several times we can repeat that.
-
5:28 - 5:31So actually, the conclusion from this research is that
-
5:31 - 5:34if we go on the road every four years
-
5:34 - 5:37with our healing machine -- this is the big version
-
5:37 - 5:39we have made to go on the real road --
-
5:39 - 5:41if we go on the road every four years
-
5:41 - 5:44we can double the surface life of this road,
-
5:44 - 5:47which of course saves a lot of money.
-
5:47 - 5:49Well, to conclude, I can say
-
5:49 - 5:52that we made a material
-
5:52 - 5:55using steel fibers, the addition of steel fibers,
-
5:55 - 5:58using induction energy to really
-
5:58 - 6:00increase the surface life of the road,
-
6:00 - 6:02double the surface life you can even do,
-
6:02 - 6:06so it will really save a lot of money with very simple tricks.
-
6:06 - 6:09And now you're of course curious if it also worked.
-
6:09 - 6:12So we still have the specimen here. It's quite warm.
-
6:12 - 6:15Actually, it still has to cool down first
-
6:15 - 6:17before I can show you that the healing works.
-
6:17 - 6:20But I will do a trial.
-
6:20 - 6:23Let's see. Yeah, it worked.
-
6:23 - 6:24Thank you.
-
6:24 - 6:30(Applause)
- Title:
- A "self-healing" asphalt
- Speaker:
- Erik Schlangen
- Description:
-
Paved roads are nice to look at, but they’re easily damaged and costly to repair. Erik Schlangen demos a new type of porous asphalt made of simple materials with an astonishing feature: When cracked, it can be “healed” by induction heating. (Filmed at TEDxDelft.)
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 06:50
Morton Bast edited English subtitles for A "self-healing" asphalt | ||
Morton Bast edited English subtitles for A "self-healing" asphalt | ||
Morton Bast approved English subtitles for A "self-healing" asphalt | ||
Morton Bast edited English subtitles for A "self-healing" asphalt | ||
Thu-Huong Ha accepted English subtitles for A "self-healing" asphalt | ||
Thu-Huong Ha edited English subtitles for A "self-healing" asphalt | ||
Joseph Geni added a translation |