carbon fiber cloth;  bending beams;  reinforcement;  bearing capacity;  stiffness;  ductility;  Cracks

In order to study the influence of carbon fiber reinforcement on beam performance, by comparing the unreinforced concrete beams, the bending test of reinforced concrete beams in two different states of cracked and uncracked reinforced concrete beams reinforced with carbon fiber cloth was designed. In the case of the initial state of the steel bar is not yielded, regardless of whether the reinforced front beam is open or not, the main failure feature of the beam is that the carbon fiber cloth is broken in the span; Under the condition of ensuring good adhesion, the yield load and ultimate load of the two reinforcement beams are increased to the same extent. Pasting carbon fiber cloth on the bottom of the beam can effectively limit the development and extension of cracks, so the ductility and stiffness of the reinforced beam are improved. After the steel bar yields, the load is mainly borne by carbon fiber cloth, but its strength can only exert about 60%.