EMISSION & NDT SCIENTIFIC PUBLICATIONS
destructive testing of reinforced concrete beams using
5th National Conference on NDT of the
Hellenic Society of NDT (HSNT), 18-19 November 2005,
National Technical University of Athens.
Athanasios Anastasopoulos, Apostolos
Tsimogiannis, Timotheos Toutountzakis, Ek. Papanikolaou, A.
Emission (AE), Non-Destructive Testing (NDT) was applied
during four-point bending tests of medium-scale
reinforced concrete beams, deficient in shear.
In total four specimens were tested: one
beam without strengthening was used as a control specimen and
the remaining three were reinforced in the shear spans
with closed jackets made of continuous fiber (carbon) textiles
(meshes) in combination with either an organic bonding agent (epoxy
resin) or an inorganic one (cement-based mortar).
Two different jacket designs were used
following “conventional” and helical wrapping schemes. The
efficiency of all strengthening systems was evaluated by means
of Acoustic Emission.
The aim of NDT was
the real time monitoring of AE activity versus the applied load, the
qualitative damage characterization and the comparative evaluation
of the different strengthening schemes applied. Qualitative
evaluation was employed by means of AE energy rate per channels as
revealed from zonal location. Further quantitative evaluation and
3-D location techniques were employed in order to accurately locate
AE sources and to monitor their growth versus time and applied load.
Real time evaluation enabled the identification of failure areas and
the forecast of crack locations well before cracks were visible with
naked eye. Furthermore, the results of post processing evaluation
allowed for the verification of the witnessed failure mode (shear
vs. flexural) and the assessment of the jackets’ relative
effectiveness for shear strengthening.