Reinforcing Bar (rebar) is the backbone of most concrete projects. As temperature changes so do the materials exposed to the temperature. Concrete has a very high compressive strength, but severely lacks tensile strength, that is where rebar comes in! It has a very similar expansion/contraction rate to concrete and has the opposite strengths as concrete: very strong tensile strength, but lower compressive strength. When embedded in concrete the strengths of each of these materials shine while the weaknesses are practically non-existent!