Structural behaviour and durability of steel-reinforced structural Plain/Self-Compacting Rubberised Concrete (PRC/SCRC)

Recycled crumb rubber particles were used as partial aggregate replacement to produce Plain Rubberised Concrete (PRC) and Self-Compacting Rubberised Concrete (SCRC). This investigation aimed to determine the compatibility of optimised mixes for structural applications using steel reinforced beams by assessing mechanical properties, monotonic and cyclic flexural loading, re-bar pull out resistance, drying shrinkage, and durability. Structural classes of C20/25 were easily achievable for optimised PRC, and C30/37 for optimised SCRC. The steel reinforcement in structural PRC and SCRC had lower maximum bond shear strength, but higher bond coefficient (γ) resulting in reduced slip displacement and apparently higher kinetic energy absorption prior to the elastic limit. The increase in fractal energy dimension was similar for PRC (c. 9%) and SCRC (c. 10%) suggesting that changes in energy dissipation at the concrete-steel interface in rubberised concretes may be directly related to the modulus of elasticity of the rubber aggregates. PRC appears to be unsuitable for reinforced concrete when chloride-induced corrosion is likely to occur due to the depth of penetration. An increase in water penetration depth, water absorption coefficient and chloride ion penetration depth also occurred for SCRC, but to a lower extent enabling it to be used for XD1 class exposure conditions with moderate humidity, e.g. concrete surface exposed to airborne chloride.