EXPERIMENTAL AND NUMERICAL STUDY OF THE STEEL-CONCRETE BOND PHENOMENON - PULL-OUT TEST ANALYSIS WITH AN ELASTOPLASTIC MODEL

Resumo

Experimental and numerical analysis were performed to evaluate the bond behavior
between steel and reinforced concrete with thin bars. The pull-out test is the most used mechanical test
to study the bond phenomenon and the results of this test may adequately represent the interaction of
the materials in reinforced concrete structures. Numerical analysis based in the finite element method
may be used to better understand the bond behavior, but the numerical models need some specific
parameters that can influence the stresses and the slip, which are important to understand the interface
zone. However, the correct determination of these values is not an easy job, so in many cases the
experimental data is necessary to develop a satisfactory model. In this study a modified pull-out test
was applied with cylindrical specimens of 150x150 cm, composed by ribbed bars (CA-50) with 6.3,

8.0 and 10.0 mm, conventional concrete and bond length of 10 times the bar diameter. An elastic-
plastic model was developed to study stress bond and the failures mechanisms, using parameters

related to bar properties and the interact mechanisms between steel and concrete. The numerical model
was adequately to represent the bond in pull-out test, with results able to represent the specimen
behavior, especially for the 10.0 mm diameter bar.