ENGINEERING SCIENCES. Building Materials and Products
Kuksenko V., Makhmudov Kh., Benin A.
VIKTOR S. KUKSENKO, Doctor in Physics and Mathematics, Professor, Senior Researcher, Laboratory of Strength Physics, Ioffe Institute, RAS, St. Petersburg.
KHAIRULLO F. MAKHMUDOV, Candidate of Physical and Mathematical Sciences Laboratory of Strength Physics, Ioffe Institute, RAS, St. Petersburg. 26 Polytekhnicheskaya, St. Petersburg, Russia, 194021, e-mail: h.machmoudov@mail.ioffe.ru
ANDREY V. BENIN, Ph.D. Head of the Mechanical Laboratory Petersburg State Transport University, St. Petersburg. 9 Moscow Av., St. Petersburg, Russia, 190031, е-mail: benin.andrey@mail.ru
Diagnostics of the stressed concrete beams instability
The article is concerned with the results of the comparative study aimed to detect the damage at the initial stage in reinforced concrete beams deformed with three-point bending. The beam deformation was measured with a set of strain indicators glued on the surface of the bean, which indicated the appearance of macroscopic cracking in. At the same time, the acoustic emission (AE) method was applied for monitoring the gradual accumulation of microscopic cracks, which also signalised the nucleation of a first visible crack. It has been found that the initial stage of damaging could be detected by those strain indicators that were situated in the close vicinity of newly-appeared cracks, while the AE transducers detected the loss of load carrying capability as being situated far from the initial small-scale failure.
Key words: concrete technology, beams & girders, failures.
