Influence of cross section loss on the stress-strain characteristics of corroded quenched and self-tempered reinforcing bars

Many ageing reinforced concrete structures are affected by severe damage of reinforcing bars due to corrosion. Accurate knowledge the stress-strain characteristics installed is an indispensable prerequisite for realistic assessment structural safety such structures. The reduction in cross section does not only reduce load bearing capacity bars, but case hot-rolled, quenched and self-tempered (QST, process branded as “Tempcore®” or “Termex®”) also changes their characteristics. Since these exhibit three distinct microstructures core, transition zone outer annulus, each with different mechanical characteristics, overall behaviour a corroded QST bar depends on composition its residual area, which varies significantly ongoing As reinforcement widely used worldwide, this effect high importance any This study investigates influence microstructure strength ductility subjected axisymmetric loss. In comprehensive experimental campaign, 31 tensile tests continuously reduced diameters were conducted, exploring contribution concentric layers cylindrical behaviour. Experimental results indicate pronounced variation over section. Based observations, simplified model was developed relationship between loss A validation shows excellent agreement data.