1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Reuse of waste tyre rubber particles as a sustainable replacement for mineral aggregates in concrete has been an object of research for several years. The severe impact of rubber particles in concrete’s mechanical performance (substantial reduction of its compressive strength), has led researchers in examining the confinement via externally bonded composites as a possible solution to mitigate the negative impact and further enhance the concrete’s characteristics. This study aims to evaluate the mechanical performance of rubberised concrete confined with textile-reinforced mortar (TRM) jackets subjected to monotonic concentric compression. For this purpose, five trial concrete mixes were examined, in four of which rubber particles replaced fine natural aggregates by volume, with a replacement ratio of 25%, 50%, 75% and 100%. Overall, 70 cylindrical specimens from all mixes were tested (diameter 100 mm, height 200 mm). From each mix 8 specimens were unconfined, 3 were confined with 1 TRM layer and 3 confined with 2 TRM layers. The results showed that the compressive strength of rubberised concrete decreased up to 78.1% for the highest replacement ratio. Confinement increased the compressive strength up to 35.5% for 1 TRM layer and 49.6% for 2 TRM layers, respectively. The residual strength also increased with an increasing rubber content. However, it was found that incorporating rubber in concrete increased its axial residual strength effectively only when 2 layers of confinement were applied. The findings of this study indicate promising potential for using confined rubberised concrete, particularly in applications where high deformability of elements is crucial (e.g. in seismic-prone areas).