Open AccessDETERMINATION OF DEFORMABILITY PARAMETERS OF CONCRETE SAMPLES BY THE FORMULAS OF FRACTURE MECHANICS
Author(s) -
B.A. BONDAREV,
N. N. Chernousov,
V.A. STUROVA
Publication year - 2020
Publication title -
construction and geotechnics
Language(s) - English
Resource type - Journals
eISSN - 2687-0908
pISSN - 2687-0894
DOI - 10.15593/2224-9826/2020.2.08
Subject(s) - deflection (physics) , materials science , bending moment , structural engineering , deformation (meteorology) , pure bending , mechanics , three point flexural test , fracture mechanics , limit load , composite material , bending , finite element method , engineering , classical mechanics , physics
To determine the deformability parameters of concrete samples by the formulas of fracture mechanics, equilibrium tests were carried out at the stage of local deformation of the sample, which showed the correspondence of the change in external forces to the internal forces of the material resistance with the corresponding static development of the main crack. For the same purpose, the samples are tested for bending with an initial notch and the “load-deflection” diagram is recorded. In this work, we presented a test scheme for a specimen with a notch (crack) and constructed a diagram of the deformation of a specimen under bending “load-deflection”. Based on it, it is possible to predict the destruction of the material, that is, to determine the value of the load at which the limit value of deflection or the displacement of the outer edges of the notch (opening the throat of the crack on the lower surface of the specimen) can be taken as the moment of loss of the resource of the material. Also, we examined the deformation of a concrete sample during three-point bending and presented a diagram of the deformation of a concrete sample within the plastic zone. Dependencies were derived for determining the ultimate relative strains under tension and bending. Based on the results obtained, the state diagrams of the stretched concrete and the deformation scheme of the normal section of the concrete sample were constructed. As a result, the conclusion and convergence of the results.