> The attached photos show a deep foundation element of 250mm in diameter at the time of the first tests and the same foundation after excavation.
The theoretical length of this foundation is 7 meters, that deduced from the mechanical impedance tests is 2.7 meters for a plane waves propagation velocity of 3500 m / s and 3.2 meters for 4000 m/s.
The mobility of the vibratory response is abnormally high. The dynamic stiffness is abnormally weak.
These elements coming from the analysis of the vibratory response led the Rincent agency of Recife in North East of Brazil to alert the control office and the client about these non-compliant results. Hence, these investigations revealing a defect of concrete.
Concrete provides continuity of propagation of waves and this type of non-conformity is difficult to detect with the echo method which only uses the propagation of plane waves.
Rincent BTP Services SAS
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