Our shared cultural heritage comes in many forms and environments, not all of which are conducive to their long-term preservation. For example, salts are inevitably present in porous building materials like masonry, or natural limestone or sandstone walls. The way salts can migrate through these materials poses dangers to cultural heritage such as wall paintings. For example, salts can be drawn along with water and precipitate out in a bloom of salt on the surface (termed ‘efflorescence’), at interfaces (e.g. ‘blistering’ cement), or within a wall (‘subflorescence’). They can also host damaging bacteria that thrive in high levels of salt. Further complexity arises from the sensitivity of many salts naturally present in building materials to minute variations in environmental conditions. For example, sodium sulphate has two hydration states that both occur near room temperature, but which differ in volume by over 300%: the stresses induced by changes between these states suffices to shatter rocks!
In this project, you will develop models of the physical and chemical processes giving rise to salt-induce damage to wall paintings and other cultural heritage. The aim of the work will be to predict when and where salts will appear for several buildings and sites operated by English Heritage, to inform their conservation efforts.
The project will combine numerical modelling with mock-up experiments and detailed observational campaigns at field sites, such as Farleigh Hungerford Castle, Conisborough Castle, Tynemouth Priory and Cleeve Abbey. The modelling approach is inspired by the methods developed to solve similar problems in hydrology, involving mineral transport through soils. Finite element and pore-network models can capture how fluids move and transport material through porous structures, like sandstone. Within this type of model, salts can move with the water, or diffuse on their own, can precipitate out as a solid and generate mechanical stresses.
In designing and adapting such models you will be guided by extensive data on environmental and physical conditions supplied by English Heritage. You will also travel to these sites to map the transport properties, salts distributions, and how they change over the course of your PhD. With your models further tested by lab-based experiments on the expression of salts in similar materials, your aim will be to make confident predictions about the dangers posed to these internationally important sites by salt-based deterioration and help with the design and monitoring of mitigation strategies.
NTU Director of Studies: Associate Professor Lucas Goehring
NTU Secondary Supervisor: Professor Haida Liang
External Supervisor from Coventry University: Associate Professor Ran Holtzman
External Advisor from English Heritage: David Thickett
For the eligibility criteria, please visit our how to apply page.
How to apply
We are looking for motivated, engaged individuals to join our doctoral community. If you are interested in applying for one of the proposed Studentship projects, visit the "how to apply" page to access our application portal: please note, you will need to use the ‘NTU Doctoral Application 21/22’ form.
As you are applying for a project, your application should clearly outline which of the projects advertised you wish to apply in Summary of Proposed Research Topic. In Research Proposal and Personal Statement, please give up to 1,500 word statement of why you are interested in the project you are applying for and how you would engage with the research proposed. Think about the outline and research aims for the project and how you would approach them, as well as showing your understanding of the field and how the project will contribute to or challenge existing research. Your statement should focus on the framework of the project, to give the panel a clear idea of your understanding of the research project/topic. You will also need to include a bibliography or reference list for any work you cite.
Your skills, experience, motivation for pursuing doctoral study, and interest in the field should be included as part of your 500 word Previous Experience and Personal Statement.
Please note that only applications to the advertised projects will be accepted as part of this funding call; do not use your application to propose your own research project.
The application deadline is Friday 18 February 2022.
Fees and funding
This project is fully-funded by the Cultural Heritage Research Peak Studentships Scheme.