The sleeve connection is also a steel bar joint, and there are requirements in the design of the joint position and regulations. In the case that the incoming steel bar is 8m, try to make full use of the uncut, 9m long steel bar as far as the design and specifications allow. Especially in the basement raft foundation reinforcement, can make full use of the original length of the reinforcement, careful ingredients, can be saved. Of course, rebar ends are required.