Siti Haji Aji

School of Planning Architecture and Civil Engineering
David Keir Building, Stranmillis Rd., BT9 5AG
Room 0G.312B
Tel 02890975606


M.Eng (Hons) Civil Engineering, Queen’s University Belfast (2012)

PhD Title

The development and optimization of Ultra High Performance Fibre ReinforcedConcrete (UHPFRC) in thin elements.

PhD project Description

Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) is a new material in the construction field due to the presence of pseudo strain hardening and strain softening. It is known that the mechanical properties of this type of concrete are superior compared to that of ordinary reinforced concrete. UHPFRC has high strength in both tension and compression compared to normal concrete. The compressive strength of UHPFRC is between 150 to 250 MPa, where in normal concrete the compressive strength is between 30 and 50 MPa. UHPFRC also has higher energy absorption in the post crack region which then makes it an efficient protective material for new structures. Other than high strength, UHPFRC has higher fracture energy, when compared to normal concrete. The fracture energy of light weight concrete is around 110 J/m2, while that of UHPFRC is between 15,000 and 40,000 J/m2.

This research project will investigate the characteristics and its properties together with the applications of this material. The main aim of the project is to develop the use of Ultra High Strength Fibre Reinforced Concrete (UHPFRC) in thin elements particularly in raised access floor tiles. The emphasis will be given on the development of the tiles with high strength but with a low weight of approximately less than 20kg. The study will also include the size effect of structurally sized members with UHPFRC materials. The research project will comprise the modelling of UHPFRC prisms and tiles to understand more of the structural behaviour of the material.


Prof. Marios Soutsos, Prof. Jian Fei Chen, Dr. Desmond Robinson


Poster(s)/ Presentation(s)

The challenges of accurately modelling Ultra High Performance Fibre Reinforced Conrete (UHPFRC) for static and dynamic behaviour. Sustainable Built Environment for Now And The Future. National University of Civil Enginering, Vietnam


Ultra high performance fibre reinforced concrete (UHPFRC), Finite Element Modelling, Fracture mechanics.

Research Interests

Ultra high performance concrete, fracture mechanics, FE modeling,  

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