Dynamic tests on a steel-joist concrete-slab floor

Dynamic properties have been determined for a composite steel-joist concrete-slab floor using heel impact and various shaker tests. The three modes located at 7.5, 12.4, and 18.7 Hz exhibited increasing numbers of nodal lines parallel to the joists.Application of vibration annoyance criteria for footsteps indicated that the floor was unsatisfactory. These criteria, presented in CSA Standard S16.1, Appendix G, had been derived specifically for the lowest mode of the floor. Detailed evaluation of the experimental results, however, shows that mode 1 has satisfactory vibration characteristics as a result of its high damping value, whereas mode 2 is identified as unsatisfactory. This is corroborated by subjective assessment. Vibration tests from walking steps were monitored and suitably filtered. Good agreement was found between the annoyance criteria derived from the heel impact test and those for "sustained vibrations" applied to the walking tests.Based on the dynamic properties of the floor, an assessment i...