Finite Element and Experimental Analysis of Bond Behavior Between Reinforcement and Concrete Containing Fibers, Silicafume and Nanosilica

Bond behavior between reinforcement and concrete, due to increasing application of reinforced concrete, is one of the most important issues all over the world. In this research, which has been done experimentally and finite element (FE) modeling (using ABAQUS software), 36 mixtures are deigned considering three cement strength grades and various percentages of polymer fibers, silica fume and nano-silica. The effects of these admixtures on the bond behavior between concrete and reinforcement and also the compressive strength of concrete are investigated. The method of applying nonlinear spring (translator) for finite element modeling is presented and the model is analyzed using nonlinear dynamic analysis. The results yielded acceptable correlation between experimental and FE model. Since there are some translators in model, it can be mentioned that the results of bond slip are not influenced by meshing algorithm. Moreover, comparison of the experimental and FE results showed that while the effect of fiber in bond strength is negligible, it can be so effective in determining the failure shape. The combination of silica fume and nano silica can also improve the bond strength about 20% so that applying equal amount of these two admixtures may leads to the best strength results.