Why is the round bar bent?
Gripping force: generally expressed by the strength of the concrete.Physical quantity of reinforced concrete to resist sliding ability, its sliding force divided by the holding area to express (Mpa), under normal circumstances, the bond strength is along the steel and concrete interface shear stress, which is the bond stress.
Round steel with hooks the aim is to increase the bond between concrete and prevent the component in the tension will be reinforced. Therefore, round bars should be 180 degrees of hook, should set up 90 degree hook ribbed bar.
In fact, the stress and deformation complex around reinforced concrete, bond stress varies with grip length of the rebar so bond strength with steel type, shape and position of the embedded in concrete, different direction and change, is also related to concrete strength, concrete compressive strength the higher the strength, the bond strength is generally determined by R=P/3.14dL. P for pullout force, D, rebar diameter, L, steel embedment length.
