FRESHLY COMPACTED CONCRETE DYNAMIC RESPONSE TO HARMONIC VIBRATIONS IN PRECAST BRIDGE BEAMS

Oana TONCIU

Abstract


When fresh concrete is poured into the metal patterns of the beams of approx. 40...42 m used in the construction of bridges and viaducts, external vibration is activated with inertial vibrators arranged along the length of the metal pattern. The paper presents the parametric analysis of the compaction of freshly poured concrete into molds with equipment with external inertial vibrators. The stiffness and damping values of the fresh concrete were determined according to its physical nature and composition, in steps of the degree of compaction with variations discrete stiffness and critical damping fraction based on the Voigt–Kelvin rheological model. In this context, the families of characteristic amplitude-frequency curves highlight the fact that the post-resonance regime is favorable to the compaction process.

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References


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