In the last decades, a large number of studies have been carried on the use of rubber particles derived from end-of-life tyres as partial replacement of stone aggregates. Despite a significant decrease in concrete mechanical properties, such as compressive strength, has been observed, rubberized concrete (RuC) shows an increment of ductility, energy dissipation and damping capacity. Nevertheless, experimental researches on the behaviour of RuC in structural members is quite lacking, especially referring to the interaction between rubberized concrete and steel rebar. For this reason, the bond-slip behaviour between RuC and deformed steel bars is investigated in this paper with the aim of evaluating the influence of volumetric aggregate substitution. A reference ordinary Portland concrete (OPC) mix and four different RuC mixtures, with increasing percentages (i.e., 6%, 12%, 18% and 24%) of rubber particles as partial replacement of fine natural aggregates, have been tailored and tested. The results showed a decay, up to 20% in respect to the reference mix, in bond strength when RuC contains more than 12% in volume if rubber aggregates. Bond strength decrease has been correlated with the simultaneous decrement, up to 37%, in compressive strength observed for the same percentages of aggregates substitution. On the contrary, residual bond stress slightly increases of about 10%, similarly to concrete toughness, with the content of rubber.
Bond strength of rubberized concrete with deformed steel bar
Romanazzi V.;Leone M.;Aiello M. A.
2021-01-01
Abstract
In the last decades, a large number of studies have been carried on the use of rubber particles derived from end-of-life tyres as partial replacement of stone aggregates. Despite a significant decrease in concrete mechanical properties, such as compressive strength, has been observed, rubberized concrete (RuC) shows an increment of ductility, energy dissipation and damping capacity. Nevertheless, experimental researches on the behaviour of RuC in structural members is quite lacking, especially referring to the interaction between rubberized concrete and steel rebar. For this reason, the bond-slip behaviour between RuC and deformed steel bars is investigated in this paper with the aim of evaluating the influence of volumetric aggregate substitution. A reference ordinary Portland concrete (OPC) mix and four different RuC mixtures, with increasing percentages (i.e., 6%, 12%, 18% and 24%) of rubber particles as partial replacement of fine natural aggregates, have been tailored and tested. The results showed a decay, up to 20% in respect to the reference mix, in bond strength when RuC contains more than 12% in volume if rubber aggregates. Bond strength decrease has been correlated with the simultaneous decrement, up to 37%, in compressive strength observed for the same percentages of aggregates substitution. On the contrary, residual bond stress slightly increases of about 10%, similarly to concrete toughness, with the content of rubber.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
