ABSTRACT To understand the weakness of concrete and the impact of adding reinforcement to concrete on its strength under stress. We first build two identical concrete cylinders, one for the compression test and another one for the tensile test. The result shows that concrete’s strength is much stronger in compression stress than in tension stress. Then to test out the impact of adding reinforcement to concrete on its strength under stress, we build two similar concrete beams except one has reinforcement( rebar) cast inside the beam and one does not. Then we put them in the press, the result comes …