Stress-strain behavior of textile reinforced concrete subjected to biaxial tension: Fid-Bau Portal

Stress-strain behavior of textile reinforced concrete subjected to biaxial tension

Jesse, D. / Michler, Y.L. / Jesse, F.

Textile reinforced concrete is known for having a load-bearing behavior which is very sensitive to bond properties of the fabric reinforcement. Since there is a lack of information on the stress-strain behavior under biaxial loading a study has been started to conduct the behavior under tension-tension loading. Multiaxial loading on components of reinforced concrete results in an interaction of the load carrying behavior in the two main directions. If this interaction is neglected, there is the risk of wrongly estimating the load-carrying behavior. A special test setup for biaxial loading of TRC has been developed. The main objective of this paper has been to discuss the influence of additional reinforcement layers in the load introduction area of the specimens on the stress-strain behavior under biaxial loading. As the analysis of stress-strain curves and strain-field diagrams shows, the mean strains decrease orthogonally to the loading direction toward the specimen's border. Marginal distortions have been identified to be the main reasons for that. They are caused by an increased reinforcing ratio (material-induced marginal distortions) and by load introduction cogs (geometrical induced marginal distortions). Both effects lead to an increased stiffness in the margin of the specimen and thus to a strain handicap in the central measuring area. Reduction of extra reinforcements and cutting of extra reinforcement in the margin of the specimen eliminate this stiffening influence effectively. The middle axis of the measurement area can be considered as undisturbed. Thus for upcoming test series it is assumed that this test setup and uniaxial reference tests will lead to directly comparable results.