Sustainable structural strengthening and durability recovery for improving service-life of fire-damaged concrete structures (Advert Reference: RDF21/EE/MCE/REZAZADEHMohammadali)

The performance of a reinforced concrete (RC) building is destructively reduced when exposed to fire, influencing the safety and serviceability of concrete structures. Extensive cracks appear in concrete when exposed to high temperature, which causes a significant reduction in terms of structural performance and durability of fire-damaged concrete structures. To avoid demolishing and rebuilding of fire-damaged concrete structures, aiming to reduce the consumption of natural resources, new strengthening solutions are required to improve their residual strength and durability, and make them sustainable and reliable. Regarding the structural strengthening of fire-damaged concrete, fibre reinforced polymer (FRP) composite materials have been extensively adopted for recovering their residual strength, due to the several advantages of FRPs. However, the potentialities of FRPs to recover the durability of fire-damaged concrete structures need to be explored.

This proposal brings a sustainable FRP-based strengthening technique to simultaneously recover the residual and moisture-related durability of fire-damaged concrete columns, with a good balance between structural performance, sustainability, and cost-effectiveness. This technique is more cost-effective than traditional FRP techniques by the benefits of applying prestressing force on FRP sheets, with the aim of introducing higher lateral confinement pressure to concrete columns without the need of extra FRP materials. In addition, the lateral confinement pressure, caused by prestress force, reduces the lateral expansion of concrete, and closes the cracks created due to high temperature, resulting in the higher structural performance, long-term behaviour, and durability. An experimental program will be organized to evaluate: (I) residual strength and durability of fire-damaged concrete columns, (II) their strengthening using the FRP-based prestressing technique.

The other innovation of this proposal is to develop an integrated Machine Learning (ML)/Finite Element (FE) model in ABAQUS commercial software to capture complex deterioration mechanism of concrete exposed to fire. A new FE model updating technique using ML is developed to simulate the changes in concrete mechanical properties due to moisture durability, leading to more confidence: to assess damaged RC structures, estimate their service-life before and after strengthening, and decide to repair or replace. For this purpose, a time-dependent damage function using supervised ML with nonlinear regression algorithm is developed and implemented in the FE model to accurately predict the behaviour of fire-damaged concrete exposed to moisture.

The project results will be shared with the scientific community through ISI-Q1 journal publications, and European fib 5.1 (FRP Reinforcement for concrete structures) and RILEM FTC (Durability and Service Life of Concrete) committees, as the Principal Supervisor is the member.

This RDF studentship appears to be an ideal opportunity to further develop novel sustainable FRP-based strengthening techniques for fire-damaged concrete structures, which contributes to achieve sustainable economic growth of FRP construction industry in the UK and makes FRPs ideal for widespread strengthening applications nationally and internationally, to avoid rebuilding which causes further environmental degradation.

The principal supervisor for this project is Dr. Mohammadali Rezazadeh.

Eligibility and How to Apply:
Please note eligibility requirement:
• Academic excellence of the proposed student i.e. 2:1 (or equivalent GPA from non-UK universities [preference for 1st class honours]); or a Masters (preference for Merit or above); or APEL evidence of substantial practitioner achievement.
• Appropriate IELTS score, if required.
• Applicants cannot apply for this funding if currently engaged in Doctoral study at Northumbria or elsewhere.

For further details of how to apply, entry requirements and the application form, see
https://www.northumbria.ac.uk/research/postgraduate-research-degrees/how-to-apply/

Please note: Applications that do not include a research proposal of approximately 1,000 words (not a copy of the advert), or that do not include the advert reference (e.g. RDF21/EE/MCE/REZAZADEHMohammadali) will not be considered.
Deadline for applications: 29 January 2021
Start Date: 1 October 2021
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