Engineers without Borders

Mud brick course

Imperial College London 7th February 2009

I gave a course for Engineers without Borders at Imperial College, London as part of their Development Construction weekend. The course taught how to identify the best soils for making mud bricks, how to make and how to test mud bricks, so that the participants would be able to make bricks in a development situation, such as post disaster reconstruction or new construction in developing countries.

The full day course began with a talk on different types of mud brick construction, looking at cob, adobe and rammed earth. We discussed the suitability of mud bricks in construction, and where they are used. I described some of my work on the fundamentals of mud bricks, and where they derive their strength and stiffness.

The second part of the day was a practical, looking at soil selection and mixing. The students divided into groups with each group trying to find a good mixture of sand and clay to make a quality mud brick. We performed some basic tests which could be carried out in the field such as the drop test and field sedimentation.

The third part of the day was consturction and testing of some mud bricks. Once a good soil mix had been found, the optimum water content was determined and the mixture compacted in cube moulds.

Finally, we tested the finished bricks, to see which soil mix was stronger. Some of the bricks were tested on the day, and some two weeks later.

If you would like a copy of the course notes or presentations, please contact me.

Please contact me if you would like me to give a course like this.

Mixing sand and clay

The drop test

Sedimentation

Field compression testing methods. It took 50kg