Modelling precast concrete piling for use in the geotechnical centrifuge

This paper presents initial work developing a new 'micro-reinforced concrete' which can simultaneously model the stiffness and strength properties of reinforced concrete sections under bending and soil-structure interface shearing characteristics for use in centrifuge modelling. The model uses gypsum mortar as a scaled concrete and steel wire as reinforcement, from which singly-reinforced concrete beam-column sections 12.5 mm square with varying amounts of longitudinal and shear reinforcement were produced. Depending on the scaling factor employed, this section represents a wide range of prototype precast concrete piles from 250 mm square at 20-g to 1250 mm square at 100-g. A range of tests were conducted on the model sections to characterise their mechanical behaviour. The new concrete has a low modulus of rupture such that the models replicate ultimate strengths and failure modes of real concrete sections at prototype scales without exhibiting the significant over-strength commonly associated with small scale models