Title:
Voids Beneath Slabs-on-Ground
Author(s):
Hal Amick, Blong Xiong, Ning Tang, and Michael Gendreau
Publication:
Concrete International
Volume:
31
Issue:
7
Appears on pages(s):
29-33
Keywords:
impulse-response test; nondestructive testing; slab-on-ground; vibration
DOI:
Date:
7/1/2009
Abstract:
Concrete slabs-on-ground are popular for research facilities because they don’t exhibit the resonance characteristics of suspended slabs. Occasionally, a slab-on-ground separates from the subgrade, leaving a void that allows the floor to behave more like a suspended slab and may lead to cracking. To detect these voids, determine their horizontal extent, and verify that corrective actions have been successful, the frequency-dependent response of the slab to an impact load can be measure using impulse-response testing. The results of one such study, with measurements before and after remediation by grout injection, are presented.