4.2　Reinforcement Steel Bar Works

4.2.1　The hook shall be formed at the end of HPB235 rebar with the lap splice.The hook may not be necessary for HRB335，HRB400 and RRB400 rebar.The rebar hooks and the ends of tying wire shall be opposite to the cover.

4.2.2　When the lap splice is applied，the lap length of rebar shall meet the design requirements.When there is no design specification，the lap length of rebar shall be 40 times of the rebar diameter.When the welded splice is applied，the splice detail and technical requirements shall comply with the relevant regulations of the current national standard JGJ 18 Specification for Welding and Acceptance of Reinforcing Steel Bars.

4.2.3　When the length of vertical rebar of circumferential shell is not long enough，it shall be welded，and mechanical splice may be also applied.The mechanical splice of rebar shall comply with the relevant provisions of the current national standards JGJ 107 General Technical Specification for Mechanical Splicing of Bars and JGJ 109 Specification for Taper Threaded Splicing of Bars.

4.2.4　Rebar splice shall be staggered.At one connection divisional，the numbers of bars with lap splices shall not be more than 25% of the total amount.The numbers of bars with welded and mechanical splices shall not be more than 50% of the total amount.

4.2.5　The interdivisional of rebar shall be solidly tied with wire.For the reinforcement mat of the foundation slab，except the total interdivisionals at two outer rows shall be fully solidly tied，interdivisionals at the central area may be tied in a staggered way.But it shall be ensured that no displacement for the load-bearing rebar.

4.2.6　The vertical rebar of the shell，which are inserted into circumferential shell，shall be grouped as the design requirements，also solidly tied or welded with the foundation rebar.Meanwhile，preventative action shall be taken for the rebar displacement.