Taking the Lab to the Stage

Erik Schlangen looks at cracks in buildings and roads, and considers the material to be ill, not broken. And the ill patient can be healed, as long as initially he contains some simple tricks.


In utter silence, a scientist in lab coat shows up on the TEDxDelft stage, and then there is also a lot of smoke around his small lab setup – you would think Professor Barabas has walked out of your childhood comics. Still in silence, a sample of asphalt broken in two pieces is put in a microwave.

And then we learn what is going on. Regular asphalt has two main disadvantages, Erik explains: water stays on the surface, resulting in splash water and puddles, and driving over asphalt results in high levels of noise, which is a disturbance in a densely populated country like the Netherlands.



Luckily, a solution was found by developing ZOAB (very porous asphalt concrete). As the name says, it is a very porous material, which means that water can drain right through it, and it also works as an insulator for the traffic noise. The architecture of the material is that it is mostly aggregates (stones), with a very small layer of bitumen keeping the stones together.

If you want to know more about asphalt, and how it is made (explained with wonderful cartoons), check out this TEDx talk by Dr. Niki Kringos:


The advantage of the ZOAB is however closely knit to its disadvantage: it wears out easily. The layer of bitumen shrinks, cracks and ultimately causes the connection between the stones to get lost. Raveling occurs, stones come off the surface of the road and can damage your windshield or create potholes.

However, with some smart tricks inside the material, the service-life of the roads can be doubled. The brilliant idea is to mix steel wool fibers into the bitumen. Steel conducts heat very well (compare to placing a steel pan on a stove), and if you add steel fibers to bitumen, the road can be repaired by using heat. Under the influence of heat, the steel fibers will warm up, and melt the bitumen again such that the cracks disappear, and the road is ready for a second round.

After extensive testing in the laboratory, it turned out that a road from self healing asphalt can be used twice as long without needing replacement if it is heat-treated (with an induction machine) every 4 years. With the simple trick of adding steel wool fiber to the bitumen, the government can thus save a lot of money.

The performance ends as it began, with the focus on the lab on stage: the asphalt sample in the microwave is ready. And then the moment of truth, when Erik only holds the top part of the specimen: yes it works, the asphalt specimen that was broken into two parts looks as if nothing happened!

This post originally appeared on the TEDx Delft website as a live blog.

Our lab on TV

That's our lab in which they are interviewing! And I'm briefly showing up at 1:29, in between the talks for the parents of the students.

Preparing a presentation without slides

On Tuesday I am giving a presentation. That is not breaking news at all, except for the fact that I just have to go and talk for 15 minutes without slides to a non-technical audience.

Here's how I prepared for it:

1. Ask for advice

I went to ask a more experienced staff member for advice, and I was lucky enough to get his preparation sheet of last year.
The useful hints I got were:
- Avoid jargon,
- Point out and show whatever you can to keep the audience's attention,
- Compare to examples and objects from everyday life.

2. What are the important questions to answer?

I tried to imagine what I would be thinking if I'd be walking into a factory or a lab totally unrelated to my field. What came to my mind are the following:
- First of all, where am I?
- Who is working here?
- What are they doing here?
- Why is this research necessary?
- What are these objects?
- How do they work? How do they measure?
- How much time does a test/ a step in the process take?
- What results are obtained so far? What have they learned from this?

3. Mindmap

The first thought I had was to use flash cards and keep these in my hands during the presentation. However, to avoid staring at my cards, I decided I want to go and speak out without any aid except all the material around me in the lab. To have an idea of what I am going to talk about, I sketched up a mindmap based on the questions I came up with previously. Then I started to organize the facts I want to talk about and the ones that I had from last year's presentation around these questions to structures my talk.

4. Practice

If 2 minutes of public speaking requires 1 hour of preparation, I am supposed to roughly spend a work day preparing my talk. I'm planning to go over this several times on Monday, and discuss it in the lab to see if it is accessible enough.

This is the first time I've laid out a presentation around a few basic questions, and a mindmap. I'm quite curious to see how this will work out. What I've learned by preparing this presentation so far, is how easy and effortless mindmapping can be to structure your thoughts to prepare for a presentation.

A few lessons from the lab

The past year, I've been conducting an enormous amount of large-scale experiments (my funder is quite generous). Tomorrow I'll have finished large-scale test number 98, and I will have tested 14 slabs (half-scale slab bridges) and 9 wide beams/slab strips. In this past year, I've learned by trial and error how to get a good routine and manage the testing program.

1. Plan
There's much more to plan about doing an experiment than the experiment itself, obviously. You will need a planning to arrange the delivery of your material, the fabrication of your specimens, side testing and then the course of the experimental program itself. Even though your planning will change (mine is changing frequently because of unexpected delays: sickness of technicians, the carpenter being unavailable,... ), you still need a planning to make sure you won't forget anything and to estimate the time every step will take you.

2. Prepare
Don't walk into the lab with empty hands. When I go to the lab, I have my fixed set of documents along with me: a sheet with predicted values to immediately compare my test result to and a table that I fill out during testing in which I note down observations for every load step. I also take the camera along with me to photograph the failure patterns (and sometimes something to snack on).

3. Classify
Don't wait until months after testing to organize and classify your data and notes. Right after a test, I save the raw data and pictures into their respective folders. I add results into tables which I build up test by test. I write a short summary in my lab book. You get the picture: take action immediately to keep it all neatly organized.

4. Automatize
If you carry out a large test series, try to automatize your data processing as much as possible. Even though programming might take you a few days, the benefits will return to you in the long run. I for example wrote a Matlab code that reads my raw data and returns all plots and numerical values I need for the considered test. Programming is by far not my specialty, but I learned something while writing my code, and now I generate all plots in just a few seconds. That sure is a win.

5. Write
Don't wait until months after the experiment to write your report. With my large testing program, I sketched an outline of how I want to discuss every specimen and test and made it a good habit to complete the report after finishing a specimen. Initially, I could remember every detail of every test, but now I notice that every now and then I have to check in my report to verify what happened during a certain experiment. There's a limit to our memory, so you'd better not wait until you start confusing to write down your results and observations into a report.

6. Smile
You probably won't be working all by yourself if you carry out a series of tests. Respect the technicians you work with, don't treat them as "inferior" because they are not pursuing a doctoral degree. Arrive in time when you need to fabricate a specimen and technicians are volunteering to help you. (I'm writing this because I've seen bad examples, unfortunately). It might be hard work (my muscles used to hurt terribly after working in the lab for the first months), but make sure you enjoy. Joke around, have fun, and above all: smile.