18. Wall rebar arrangement

Transcription

1 18. Wall rebar arrangement 1) Sequence of rebar arrangement The worker is not allowed to change the rules and instructions of reinforcement without permission. All the reinforcement should be in accordance with drawings and specifications. Especially in retaining walls, if the retaining wall, which needs double reinforcement, is placed in the sequence of the first main bar, assist bar, the second main bar and then another assist bar, it might be an easy way but wrong one. All the placement should be in the specified sequence. Placement sequence of wall suggested below main bar width fixing bar sub bar width fixing bar reinforcement bar Place the stirrup closing bar densely and keep the thickness exactly. Especially in the reinforcement of water tank, fabricate the reinforcement as specifically suggested. And place the reinforcement at a time. In case the tank is big, the reinforcement should be in zigzag and in the top span tying wire should be wound at least one time before tying. If not, main bar would swing and would not maintain the required shape. Simple cut bar reinforcement or hooking in the bar is also a wrong reinforcement.

2 2) Principle of assembly and rebar arrangement binding saddle tie with twist corner it should be tied with 1,2 times wound depending distance tying to maintain distance of upper part Assist bars might deflect when concrete is cast-in or due to loose bindings. To avoid this undesirable deflection, width-fixing bar, which is similar to stirrup in shape is fabricated to place in assist bars. Begin the placement of assist bars from 100mm above the floor place the stirrup Stirrup(closing bar) at every third step Caution in reinforcement of retaining wall When numbers of bars are placed in the retaining wall, the worker should be considerate. If the tie between main bars and assist bars is loosened, the reinforcement would lean toward. Make sure that tying of main bars and fixing bars always go together in turn.

3 3) Crosspoint main bar and horizontal rebar arrangement <Single arrangement> <Single and double arrangement> U bar wall horizontal rebar U bar wall vertical rebar wall horizontal rebar <Double arrangement> U bar wall horizontal rebar <Straight wall>

4 4) Details of wall on top floor <Top floor outer wall> <Top floor inner wall> roof floor slab slab upper part bar 90 standard hook roof floor slab tension splice wall vertical bar wall horizontal bar over 150 slab lower part bar wall The end of wall vertical rebar on top floor should obtains unification by fixing correctly on slab and processed to get 90 standard hook. The upper part rebar of slab to contact outer wall should be fixing splice or making tension folding splice and wall outer vertical rebar.

5 5) Tying position of revetment(retaining wall) As a rule, bar splice in pillars and beams is not allowed, and if horizontal bar is better to be anchored in the pillar of every span. <resistance wall> <underground retaining wall> pillar pillar horizontal bar vertical bar inside outside beam outside inside outside foundation beam inside good position to tie <stirrup closing bar> B class tension splice When the inserting bars as arranged straight bar are inserted at the underground beam tension splice tension splice fixed length no problem if fixed length will be obtained As shown above left, there is a possibility for stirrup vertical bar to be protruded by the lack of cover thickness of fixing part. It is recommended to adjust to fix the bar into the stirrup.

6 6) Indication of revetment(retaining wall) arrange to 300mm distance of vertical High Density 16mm rebar arrange to 200mm distance of vertical High Density 19mm rebar arrange to 200mm distance of horizontal Density 16mm rebar arrange to 200mm distance of horizontal Density 19mm rebar <Symbol on wall > RW(Retaining Wall) = Underground wall(wall to resist against ground pressure) Wall = Wall THK = Thickness of wall V = Vertical rebar H = Horizontal rebar T = Width Tie bar H = Hunch, it is classify easily per type against tie hoop