Prof John Sweeney / Prof Tony Jefferson / Dr Robert Davies / Dr Brunella BalzanoDr Riccardo Maddalena / Mr Glen Thompson




WP4 comprises the refinement of the tendons developed in M4L, such that multiple activations are possible and new, high performance, hybrid tendons; 3D SMP (shape memory polymers) grids and SMP fibres are developed. The ultimate goal of this work is to provide a system that triaxally confines and post‐stresses the cementitious matrix such that it has greatly enhanced ductility and a high resistance to cracking.

  • Task 1 – refine and optimise the electrically activated SMP tendons that have been used for crack‐closure, with a view to achieving partial prestressing and reinforcement of the concrete itself.
  • Task 2 – research new form of hybrid tendon comprising an inner core of Kevlar or GRP and outer annulus of SMP. The essential idea is that the inner core will be tensioned during manufacture and subsequently constrained by an outer ring of SMP.
  • Task 3 – potential of preformed 3D grids of SMP tendons to provide triaxial prestress and confinement, thereby replacing conventional reinforcement and prestress in a wide range of structural elements.
  • Task 4 – work on a cementitious‐SMP fibre composite. The fibres are added during mixing and then are activated after curing. These are potentially able to close micro‐cracks and to act, very effectively, as secondary reinforcement.

Shape Memory Polymers tendons 

SMP tendons placed in moulds for concrete casting