Local bond–slip behavior between cold-formed metal and concrete

• A new local bond–slip model is developed for cold-formed metal embedded in concrete.
• A new test set-up is used to obtain the necessary experimental data.
• An analytical approach is used to develop the model.
• Developed model is verified by finite element analysis.

Composite action in systems consisting of steel and concrete depends on an effective shear-transfer mechanism between the two materials. Such mechanism for smooth steel surfaces inside concrete will be limited to the bond–slip behavior at the steel/concrete interfaces. This research investigates the bond–slip behavior of galvanized cold-formed (light gauge) steel profiles embedded in normal weight normal strength concrete. A new innovative pull-out test is presented which is convenient to set up and perform and reduces the undesirable parameters to the minimum. Global bond–slip curves for different values of concrete strength are obtained from such tests. Through an innovative procedure, mathematical equations and selected points from the experimental global bond–slip curves are used to develop a bi-linear local bond–slip model which represents the discussed bond–slip behavior. By curve fitting, empirical equations are proposed to determine the suggested model’s parameters based on the concrete compressive strength. Finally, validity of the proposed model is explored by two methods: (1) by comparing the results from analytical equations with test results, (2) by comparing the results from finite element modeling with test results. An excellent agreement has been observed in both verification methods.