During the course of my PhD I identified many further areas of research which I feel should be investigated. In particular I have identified areas which may now be better investigated following the discoveries made during my PhD.
These areas include:
- Determination of peak cement content for earthen building
- Unfired clay brick mortars
- Rates of decay in historic rammed earth structures
- Compaction optimum moisture content
- Review of existing UK rammed earth projects
- Wall top coverings
- Structural rammed earth
- Repair methods for damaged historic earth buildings
- Seismic loading
- Relative humidity in earthen buildings
- Fly ash in rammed earth
- Urine mud bricks
I have worked with Engineers without Borders and have prepared a document giving details of these and other projects.
These projects would particularly suit university final year engineering projects. If you are interested in these or similar projects, please contact me.
Potential Earth Building projects
Undergraduate, Masters and PhD projects
The behaviour of earth building in earthquakes is subject requiring much research. The international distribution of earth buildings follows that of seismic activity, and therefore when there is an earthquake, many earth buildings collapse and many people are killed. There is evidence that unreinforced earth buildings should not be used in earthquake prone areas, but more testing and modelling is required to understand the behaviour of existing earth buildings during earthquakes. Potential projects include the modelling of earth buildings on shake tables, numerical modelling of seismic behaviour, or the microscale behaviour of earth buildings under seismic loading.
Chemistry of mud bricks
There are many examples of chemicals being added to mud bricks to improve their strength or workability. These materials include sticky rice, blood, casein and lime. The underlying chemistry of these materials is not currently well understood, and the interaction of the materials in the highly unsaturated environment of dry mud bricks needs to be explained.
Earth has almost no tensile strength, and relatively little compressive and shear strength. Reinforcement of earth buildings with other materials has been practiced since antiquity. Stabilised rammed earth is often reinforced using steel reinforcement bars usually destined for concrete. The pullout strength, detailing and ductility of these systems requires further investigation. In more developing countries, Bamboo and other timbers are used to provide tensile strength to the system. The effectiveness of these systems is requiring study.
Earth building for UK construction
Rammed earth formwork development – Traditional formwork for rammed earth construction is relatively simple, but not suited to modern construction sites. Formwork used for insitu concrete is highly specialised and subject to numerous patents. Use of ‘concrete’ formwork for rammed earth production has been found to be too expensive, and so the development of specialist formwork for rammed earth in the UK is required.
Mortars for unfired earth masonry
A compaction machine for unfired earth bricks
CDM and HSE for rammed earth construction
Fundamental behaviour of earth buildings
Thermal and hygrothermal behaviour – fitting with UK building regulations
(find out what Danielas students have done)
Historic conservation – conservation of historic cob buildings in the UK