Effects of traffic vibrations on compressive strength and rebar adherence of early‐age concrete

Abstract

This paper studies the effects of traffic vibrations on the steel‐concrete adherence and compression resistance of reinforced concrete before its hardening. Tests were carried out in plain and reinforced concrete specimens featuring compressive strength of 20 MPa (28 days), with 20 mm diameter rebars. Specimens were vibrated after molding, using peak particle velocity (PPV) as a metric and applying excitation frequencies (sinusoidal signal or a sine sweep) observed in bridges. Results showed that rebar adherence was increased in all vibrated specimens (up to 33% under sine sweep signal, PPV of 5 cm/s). However, the compressive strength of the vibrated concrete was reduced in all vibrated specimens (up to 33% under sinusoidal signal, PPV of 5 cm/s). These results indicate that traffic‐induced vibrations may affect the performance of a concrete structure that underwent retrofit or widening, suggesting a non‐vibrated time interval before concrete setting to avoid structural problems.