Effect of ciling up to the failure of concrete determined by acoustic emission

Results showing how the oiling up of concrete series, differing in their aggregate
grading, affects their failure are presented. The acoustic emission was used in the test.
The determined values of initiating stress, σⁱ, and critical one
σ^cr, in the oiled up concrete and the reference, unoiled up concrete
prove that oiling up affects significantly the failure of the concrete. It has been found
that the oiling up of concrete results in the reduction of the values of the initiating
and critical stress compared to the values of these stresses in the reference unoiled
concrete series. The tests have shown this reduction to be practically independent of
the concrete's aggregate grading.