Damping in high strength concrete beams - prediction and comparison

Abstract

The response of a structure to a dynamic load is many times greater than its response to the same load applied statically. The relation between a structure's static and dynamic responses depends primarily on its damping characteristics. Cracking also significantly affects the damping in reinforced concrete structures. The authors developed a formula for predicting logarithmic decrements of damping in reinforced concrete beams using the residual crack width and the span length. But all the beams used in this formulation were of normal strength concrete (NSC). Presented herein are the test results of 15 reinforced high strength concrete (HSC) beams. Residual crack widths and logarithmic decrements of damping at each load level for each beam had been recorded. The measured damping values are compared with the values predicted using authors' NSC beam formula. The comparison shows a reasonable correlation confirming the applicability of the NSC beam damping formula to HSC beams.