Section 1

REBAR ARRANGEMENT &CONSTRUCTION CARRYOUT

1. Understanding of Drawing

1) Examination of drawingWhen construction contract is completed, the contents of the drawings are surveyed

and checked before construction work.

Although it is a rule to survey the drawings right from the 1st page, it is common to

check the scale and the number of floors of the building and then plan, elevation,

exterior appearance, lines and windows of the building .

Not only orientation, precautions and specifications, but front elevation, rear side

elevation, right side elevation, left side elevation, partial development, partial section,

and detail section, etc should be also looked over to be reminded in the construction

site.

As construction work progresses , present work should be checked and compared

with instructions on the drawings , and an entire understanding of drawings should be

preceded before the next step.

Plan, structural plan, foundation, section, etc are checked if there is any suspicious

portion because all the drawings are not made by only 1 person.

There is also necessity of discussion when there is any question or changes in the

work.

In order to make smooth and steady progress of the work, a lot of time and repeated

practice are required.

In case of small scale of construction , it is progressed from the ground to the upper

floor in general , however there is no determined rule.

As construction work is not a simple one but rather complicated, it is difficult or

impossible to explain all of the construction methods satisfactorily in written or spoken

words alone.

Clear understanding of basic knowledge is quite helpful.

Plan of reinforcement should be drawn before reinforcement , however , when the

scale of construction is large , plan of reinforcement is given in advance or shop

reinforcement are also available .

Although the trend has been to increase the usage of shop reinforcement for the

smooth progress in the crowded city , field reinforcement is explained in this book due

to the necessity of prompt applications in the field and its convenience.

Every reinforcement has its own rule , however it could be changed when necessary

under the permission of supervisor.

For example , hooks at the tip of stirrup could be changed from Figure 1 to Figure 2.

Figure 1 Figure 2

2)What is drawing?Drawings are used in every industrial field with the development of industries.

Although their types and applications are different, there are agreed rules that are

called IPC(International Graphic Code), accepted by everyone in each field.

Specified rules and standards with reference to symbols, numbers, lines and letters are

adapted to drawings to help everyone understand what they mean.

When one begins to construct a building, one should carefully consider the

implications of drawings.

In this book, plan of reinforcement is briefed to help the workers understand them

more easily.

Drawings of construction work are grouped roughly as civil engineering and

architecture.

Although there are some differences, all the contents could be understood since they

are all in accordance with IPC mentioned above.

3) Classification of drawing

① Shop Drawing

Drawings that suggest overall dimensions of each member with symbols, numbers

and lines for the construction work

② Detailed Drawing

Detailed drawings that describe shapes , types and dimensions of each element for

the bar-fabrication

③ Understanding of Drawing

Drawings are in their own sequence beginning with the title and contents on the 1st

page.

Structure drawing of Rebar is for this case.

There are several types of drawings which include machinery, electricity,

sanitation, fire protection, communication, etc according to the type of work and

there are details as follows.

A) Construction

i. Building layout

ii. Elevation

iii. Plane figure

iv. Cross Section

v. Part Detailed drawing

B) Structure

i. Drawing of column center

ii. Plane figure of structure

iii. Drawing of stairway and slab rebar arrangement

iv. List of pillar , beam and retaining walls

v. Detailed drawing of rahmen rebar arrangement

C) In general, the order of drawing is in a sequence mentioned above, and all the

drawings are in scale.

④ Scale (All the units in "mm")

Among several types of rulers used in drawings, scale is indispensable.

There are many types of scale. Among them 300mm scale is frequently used.

It has carved line in the middle of each side, colored red, blue and black to

distinguish its scale.

Scale in red ,

Scale in blue ,

Scale in black ,

Other different scales are available like ,

4) Usage of symbol

① General symbol

Description

Length

Area

Volume

Radius

Main entrance

Sub entrance

Scale

Finish

Structural plane

Indication

Rebar indication

Part cross section

Part detaileddrawing

Levelindication(Plane)

Level indication(elevation, cross

section)

No of layer &Member

SymbolSymbol

L

A

V

R

S 1/200

▽

▼

Distance of Rebar

Diameter of Rebar

High density

No. of Rebar

No. of cross section

No. of drawing

No. of cross section

No. of drawing

Serial No. of Member

Symbol per part of structure

No. per layer

EL. 0.0000

EL. 0.0000

(Civil engineering, Architecture, Structure)

(Civil engineering, Architecture, Structure)

RedBlue

Black

② Drawing Symbol

Symbol

B

N.F.

E.F.

B.O.F

T.O.F

Ab

fck

fcu(t)

D(db)

CL

H

THK.

CONC.

N.T.S

EL.

Description

Bottom

Near Face

Each Face

Bottom of Foundation

Top of Foundation

Size of a rebar(㎠)

Strength of Concrete(kgf/㎠)

Compression strength of concrete per date(kgf/㎠)

Nominal diameter of deformed rebar(mm)

Center Line

Height

Thickness

Concrete

Not to Scale

Elevation Level

Symbol

T

F.F.

E.W.

T.O.C

E.J.

C.J.

fy

fe

Fp

&

@

W

TYP.

ST’L

FL.

Description

Top

Far Face

Each way

Top of Concrete

Expansion Joint

Construction Joint

Resistance strength of rebar(kgf/㎠)

Available resistance power of ground(tonf/㎡)

Available resistance power per pile(tonf/㎡)

And

Distance

Width

Typical

Steel

Floor Level

2. Characteristic of Rebar

Throughout the reinforcement work, reinforcing bar strongly bonds to mixed concrete

and this makes floor, wall and other members very strong.

In other words, reinforcement is a bar that is embedded in the mixed concrete to make

a member strong.

Bar and concrete have low thermal expansion coefficients, 1×10-5 , and therefore

have little thermal deformation or failure, cooperatively strengthening members.

1) Production process of rebar

① Ingot : made from melted iron ore and pig iron

② Billet : made from hot-rolled ingot

③ Reinforcing bar : manufactured per type by hot-roll process from the

purchased billet

④ In SD400, S is steel, D is Deformed Bar, 40 indicates that resistance point is over

40kgf/mm2(=400N/mm2=4,000kgf/cm2).

Type

Deformed

Rebar

Symbol

SD 30A

SD 30B

SD 35

SD 40

SD 50

Classification

Green(D:General type)

White(D:General type)

Red(HD:Density type)

Yellow(HD:Density type)

Black(HD:Density type)

p.s.) KS Symbol of Deformed Rebar : indicate as SD300, SD350, SD400, SD500

Resistance Point (kgf/mm2)

over 30

30 ~ 40

35 ~ 45

40 ~ 52

50 ~ 64

2) Classification of rebar

① Regular bars : The length of one strip is 8,000mm by KS(Korean Standard).

Each bundle has almost same weight. (basis of 1-2 ton)

② Irregular bars : Irregular bars that are made of leftovers or nonuniform bars.

③ Reinforcing bars that are mainly used in the construction site are SD40 high

strength steel and SD30A mild steel, Each bar is colored yellow(HD) and green(D)

respectively in order to identify them.

Mild steel usually used as processed goods such as hoop , stirrup , etc.

3) Type & Weight of rebar

▶If the worker in the construction site prepare the bars more than needed, there

might be rust on the surface of the rebar.

To prevent oxidation of the bar, it is advised to prepare moderate amount of the

bars.

▶When you need to pile the bars near the construction site, they should be classified

and piled on the big gravels to make the ventilation easy.

And also cover the stocked bars to avoid humidity.

▶There are usually two types of deformed steel used in the construction work.

① SD30A(mild bar) - normal strength bar, has green-colored end

② SD 40(high tension bar) - high strength bar, has yellow-colored end

Type

Deformed

Bar

Symbol

SD 30A

SD 40

SD 50

Classification

Green(D)

Yellow(HD)

Black

p.s.) SD:Steel Deformed

※Size, Weight of Deformed Bar(8m)

4) Weight limit of rebar

HD10

HD13

HD16

HD19

HD22

HD25

HD29

HD32

Content

Type1tonf

Q’ty per

210

120

75

56

41

32

25

20

2tonfQ’ty per

420

240

150

112

82

64

50

40

nominal diameter(D)mm

9.53

12.7

15.9

19.1

22.2

25.4

28.6

31.8

Per each(kgf)

4.48

7.96

12.48

18

24.32

31.84

40.32

49.84

Per meter(kgf)

0. 56

0.995

1.56

2.25

3.04

3.98

5.04

6.23

1tonf(kgf)

941

955

936

1,008

997

1,019

1,008

997

2tonf(kgf)

1,882

1,910

1,872

2,016

1,994

2,038

2,016

1,994

Size of Rebar

Less Than D10

D10 ~ D16

D16 ~ D29

More Than D29

1 each

- 0.8%

6.0%

5.0%

4.0%

Weight limit

1 ton

7.0%

5.0%

4.0%

3.5%

Remark

Sampling of test piece andcalculation of weight limitshould be in accordance withKS D3504

(KS D3504)

3. Calculation for unit weight of Rebar

1) Unit weight① Unit weight is the weight of bar per 1m.

※ FYI, the basic value in drawing and the length of rebar is “mm”.

When calculating unit weight, you must convert into “m” from “mm”.

② Unit weight per rebar type

③ Basic unit conversion

1ton = 1,000kgf

1kgf = 1,000gf

1m = 100cm

1cm = 10mm

2) Calculation of length(L) in model①

②

③

Rebar Size

HD10

HD13

HD16

HD19

HD22

Unit Weight

0.56 f/m

0.995 f/m

1.56 f/m

2.25 f/m

3.04 f/m

Rebar Size

HD25

HD29

HD32

HD35

HD38

Unit Weight

3.98 f/m

5.04 f/m

6.23 f/m

7.51 f/m

8.95 f/m

4. Criterion of Rebar arrangement

1) Rebar coating▶It means the shortest distance to the surface of concrete to cover rebar surface.

Rebar coating thickness of each part must be considered in the period of plan after

considering durability, refractory, safety in structure endurance & errors in

construction carry-out.

▶There are examples of coating case as ground criterion for all construction without

segmenting the case of ground and also the case of foundation regularly.

※ By the effect of CO2, humidity, acid gas, there will be going on of neutralization

step by step from the surface of concrete.

If the coating is small, its speed to arrive rebar will be faster .

If so, the rust will expand, the adhesion of concrete coating will drop, white

phenomenon will exist, senility of structure body will facilitate.

※ Note : “direct exposure to the air of outdoor” means the case of direct exposure of

climate change and humidity change.

Concrete pouring under water

Concrete burying under ground foreverafter land pouring concrete adjoined

Concrete part to expose to outdoor

air and to adjoin land directly

Concrete part not to adjoin land and

outdoor air

Foundation

Foundation

Wall, pillar

Beam (outside exposure

beam)

Slab(foundation slab)

Slab, Wall, Under Flooring

Beam, Pillar

Shell, Member

Minimumcoating/thickness

100

80

60

50

40

40

20

40

20

RemarkRebar Size

All rebar

All rebar

over HD29

below HD25

below HD16

over HD35

below HD35

TiehoopStirrup

Spiral rebar

All rebar

Classification

(Unit:mm)

※Regarding wall, horizontal rebar should be arranged to the outside of vertical rebar.

※Regarding outside wall in underground which compressed by the land, more

arranged rebar should be arranged to the outside after comparing the arrangement

quantity between vertical rebar and horizontal rebar.

< Independentfoundation >

< Beam > < Wall & Slab >

< Pilefoundation >

< Pillar >

Coatingthickness 80

Coatingthickness 80

Coatingthickness 40

Coatingthickness 20

In Shear wall, thearrangement of rebar

should be to the insideof vertical rebar.

Wall

Coatingthickness

Coatingthickness 50

Hoop

Lean Concrete

StirrupSlab

Lean Concrete

Cushion

Coatingthickness

2) Rebar distance

3) Type of tyingRegarding the working of tying , there are folded tying(lap splice) , compressed

tying(welded splice) , mechanical spiral tying(mechanical splice).

But compressed tying(welded splice) , mechanical spiral tying(mechanical splice)

have to be effected over 125% of resistance strength(fy) in plan criterion.

① Folded tying (lap splice)

It is tying method to fold the fixed length from end part to new tying part by using

regular rope currently.

Deformed

rebar

Net Distance

Over 1.5 times of nominal diameter

Over 1.25 times of max. size of thick aggregate.

Over high value in 25mm

Classification

Distance

Net distance

※ Folded tying(lap splice)

※ Regarding beam main bar tying , you must apply B class tying if you don't

mention tying position specially.

But, you can apply A class tying if you want to tying the compressed part of

concrete. (the compressed part of concrete : upper part main bar places near center

part of span, lower part main bar places near pillar)

ConcreteStrength

(kgf/Cm2)

210

240

270

210

240

270

21.6d

28.8d

RebarSize

Under D19

Over D22

Under D19

Over D22

Under D19

Over D22

Under HD19

Over HD22

Under HD19

Over HD22

Under HD19

Over HD22

31.5d (41.0d)

39.3d (51.1d)

29.4d (38.2d)

36.8d (47.8d)

27.8d (36.1d)

34.7d (45.1d)

42.0d (54.6d)

52.4d (68.1d)

39.2d (51.0d)

49.1d (63.8d)

37.0d (48.1d)

46.3d (60.2d)

41.0d (53.3d)

51.1d (66.4d)

38.2d (49.7d)

47.8d (62.2d)

36.1d (47.0d)

45.1d (58.6d)

54.6d (71.0d)

68.1d (88.5d)

51.0d (66.2d)

63.8d (83.0d)

48.1d (62.5d)

60.2d (78.2d)

1. The length of folded tying of rebars which have different diameter must over high value between the fixed

length of high diameter rebar and the folded tying length of low diameter rebar .

2. The tying position must be placed to low stress / to compressed stress of concrete.

3. By the criterion of concrete structure plan , it is mentioned that it is available for folded tying in case of

D29~D35 rebar.

However, you have to check in advance the problem such as the net distance of rebar is not secured and

also the tying length will be exaggerated if you apply folded tying of thick rebar.

Generally, there are more advantageous case by using mechanical tying instead of folded tying in case of

over D29 rebar.

A class tying : must be zigzag(rotation) tying arrangement and arranged rebar quantity is over 2 times of

required rebar quantity which defined in total block of tying part and also under 50% of rebar tying

quantity within required folded length.

B class tying : it is available for the tying of anti-earthquake plan and generally it is applicable to all

construction site.

Regarding SD500 , you must apply 1.25times of B class tying.

The value in ( ) is the case of upper part rebar.

Tying length of deformed rebar to beextended

Tying lengthof deformedrebar to becompressedA Class TyingA Class Tying

Rebar

Type

SD30

(fy=3,000 )

SD40

(fy=4,000 )

※ The tying length of wall vertical length is available around 40db of under HD19

especially.

Example of folded tying(lab splice)

ⓐ Folded tying of vertical rebar in case the distance of rebar arrangement is different

ⓑ Folded tying of horizontal rebar Example) Length of folded tying to be extended

of vertical & horizontal rebar

Slab upperpart

Verticalrebar

Slab upper part

Tyi

ng L

engt

h of

Tying Length of Tension bar(Ls)Diameter Length

S : Distance of RebarLs : Tying length of Tension bar

Tying

Len

gth of

Fix

ed len

gth of

Tensio

n bar

Ten

sion

bar

(Ls)

Wall

Tens

ion ba

r(Ls)

② Compressed tying(welded splice)

It is the tying method to compress through heat-treatment end to end by using

machinery.

As shown in figure(A) , place 2 bars 3mm away , heat up both of the ends by using

mechanical equipment and add pressure to weld splice them figure(B), usually

available for all bars.

③ Mechanical spiral tying(mechanical splice).

As the mechanical splice method , it is rebar tying method to connect the spiral

part with nut & coupling by cutting screw by expanding the end of rebar over the

regular size.

(A) Connect Nut

(B) Connect Coupler

(C) Move Coupler

(D) Move Nut

4) Fixing and tying① In order to effect the adequate resistance strength of rebar, it is essential to obtain

the enough adhesion strength with concrete.

The more you increase the net distance & coating thickness of rebar, the larger of

adhesion strength.

② Fixing length is the buried length in concrete to effect the adequate resistance

strength of rebar and fix the length with the criterion of max. stress point of

appropriate rebar.

③ The fixing and tying length of rebar is changing by the strength of material and

type of rebar arrangement , etc.

i. It will be lengthen by using HD(high density) rebar.(SD40 is 1.33times of

SD30A)

ii. It will be shorten by using HD concrete.(inverse proportion from square root of

concrete strength)

iii. It will be shorten if net distance and coating thickness of rebar increase.

iv. It will be shorten by the restriction effect if it is surrounded by stirrup and tie

hoop.

④ Caution : If the fixing and tying length of rebar will be shorten , the resistance

strength of rebar will be reduced as long as the shortened length.

Also, in case the heavy binding of splice part of rebar needlessly sometimes,

binding has only the role to prevent the movement of rebar when pouring concrete

and also no relation to adhesion strength of rebar. (the tensile of a D25 rebar is

5.04 4.0=20.16tonf)

⑤ If the position of extended rebar for the tying of poured concrete is wrong, it is

available for bending of splice with the angle of under if error is trivial but you

need to take additional action to increase the section of additional material if error

is over that angle.

⑥ In case slab or wall rebar will be cutted by temporary exit such as material pick-up

exit, etc, you must extend the rebar which is over the length of splice to both ends

of exit.

If width of exit is narrow or the length of rebar extended is shorten , the length of

splice will be shorten when pouring exit concrete later.

⑦ Calculation of bar length

What should be added to original length : splice length, fixed length

Splice length : extra length to lap the bars

Fixed length : developed length when the bar is fixed

⑧ Method to calculate fixed length

⑨ Tension bar and compression bar

tension bar : The main usage is tension bar because rebar is reinforced material

to reinforce the tension of weak point of concrete.

compression bar : the rebar to be arranged in addition to increase the resistance

strength in concrete material and it is mainly applicable to the pillar of high

building to cover the compression.

⑩ Refer to the diagram (#22 page) for tying & fixing per rebar diameter

Splice length

Fixed length

- In case of fixing to neighbor beam -

Compression

Tension

fixed length oftension bar

Fixed length ofrebar which hasstandard hook

- In case of fixing to end pillar -

fixed length of tension bar

90°

Stan

dard

hoo

k

5) Form of fixed beam※ When arranging beam, the marked on drawing as bending bar is mainly Japanese

method of rebar arrangement.

Our standard will be cut-bar instead of bending bar(Japanese method) .

① The length to

extend to reverse

side from max.

Stress point of

fixed length.

Hook should

place over the

center of pillar.

※① is fixed length of tension upper bar.

In case of fixing with standard hook, fixed length of rebar which has standard

hook will be applied.

If not, fixed length of tension bar will be applied.

is generally fixed length of lower compression bar and it is available of

fixation if it is extended to pillar over 15cm without hook.

Fixed length

Stress(part to

effect theweight)

Return point beam

Return point is must not 1/4point. (return point of upper bar isdifferent from return point oflower bar)

6) Example of fixed length per rebar diameter① Fixed length of tensile rebar

Fixed length of tensile rebar in slab(SD 400)

※When using SD500 rebar(fy=500N/㎟=5,000kgf/㎠), apply 1.25 times

Fixed length of tensile rebar in foundation, pillar, beam, wall(SD400)

※When using SD500 rebar(fy=500N/㎟=5,000kgf/㎠), apply 1.25 times

HD10

HD13

HD16

HD19

HD22

HD25

HD29

HD32

StrengthRebar

24N/240kgf/

27N/270kgf/

30N/300kgf/

35N/350kgf/

40N/400kgf/

400

510

630

750

1080

1230

1430

1570

510

670

820

970

1410

1600

1850

2050

24N/240kgf/

300

400

540

730

27N/270kgf/

300

380

510

680

30N/300kgf/

300

360

490

650

35N/350kgf/

300

330

450

600

40N/400kgf/

300

310

420

560

Remark

370

490

600

710

1020

1160

1350

1480

490

630

770

920

1330

1510

1750

1930

360

460

570

670

970

1100

1280

1410

460

600

730

870

1260

1430

1660

1830

330

430

520

620

900

1020

1180

1300

430

550

680

810

1170

1320

1540

1690

310

400

490

580

840

950

1110

1220

400

520

640

760

1090

1240

1440

1590

General bar Upper barGeneral bar Upper barGeneral bar Upper barGeneral bar Upper barGeneral bar Upper bar

(unit:mm)

(unit:mm)

StrengthRebar

② Fixed length of compression bar

Fixed length of compression bar(SD400)

※When using SD500 rebar(fy=500N/㎟=5,000kgf/㎠), apply 1.25 times

7) Example of splice length per rebar diameter

1) Classification of tension splice

ㆍA class tying : must be zigzag(rotation) tying arrangement and arranged rebar

quantity is over 2 times of required rebar quantity which defined in total block of

tying part and also under 50% of rebar tying quantity within required folded

length.

ㆍB class tying : it is available for the tying of anti-earthquake plan and generally it

is applicable to all construction site.

2) Upper bar : horizontal rebar without concrete harded over 300mm under splice part

and fixed length

3) The rebar with folded splice without contacting directly each other in bending

material must not depart over little value between 150mm or 1/5 of folded splice

length.

HD10

HD13

HD16

HD19

HD22

HD25

HD29

HD32

24N/240kgf/

210

270

340

400

460

520

600

670

27N/270kgf/

200

260

300

370

430

490

570

630

30N/300kgf/

200

240

300

360

410

460

540

600

35N/350kgf/

200

230

280

330

380

430

500

550

40N/400kgf/

200

210

260

310

360

400

470

520

50N/500kgf/

200

210

260

310

360

400

470

520

2

2

50% 50%

Actual arranged rebar requirement

Required rebar Q’ty

Max. splice % within folded splice length

(unit:mm)StrengthRebar

① A class splice length of tension rebar

Splice length of slab(SD400)

※When using SD500 rebar(fy=500N/㎟=5,000kgf/㎠), apply 1.25 times

A class splice length of foundation, pillar, beam, wall(SD400)

※When using SD500 rebar(fy=500N/㎟=5,000kgf/㎠), apply 1.25 times

② B class splice length of tension rebar

It is available for the tying of anti-earthquake plan and generally it is applicableto all construction sites.

B class splice length of slab(SD400)

※When using SD500 rebar(fy=500N/㎟=5,000kgf/㎠), apply 1.25 times

HD10

HD13

HD16

HD19

HD22

HD25

HD29

HD32

Rebar

24N/240kgf/

27N/270kgf/

30N/300kgf/

35N/350kgf/

40N/400kgf/

400

510

630

750

1080

1230

1430

1570

510

670

820

970

1410

1600

1850

2050

HD10

HD13

HD16

HD19

Rebar

24N/240kgf/

390

520

700

940

27N/270kgf/

390

490

660

890

30N/300kgf/

390

470

630

840

35N/350kgf/

390

430

580

780

40N/400kgf/

390

410

550

730

Remark

370

490

600

710

1020

1160

1350

1480

490

630

770

920

1330

1510

1750

1930

360

460

570

670

970

1100

1280

1410

460

600

730

870

1260

1430

1660

1830

330

430

520

620

900

1020

1180

1300

430

550

680

810

1170

1320

1540

1690

310

400

490

580

840

950

1110

1220

400

520

640

760

1090

1240

1440

1590

General bar Upper barGeneral bar Upper barGeneral bar Upper barGeneral bar Upper barGeneral bar Upper bar

HD10

HD13

HD16

HD19

Rebar

24N/240kgf/

300

400

540

730

27N/270kgf/

300

380

510

680

30N/300kgf/

300

360

490

650

35N/350kgf/

300

330

450

600

40N/400kgf/

300

310

420

560

Remark

(unit:mm)

(unit:mm)

(unit:mm)

Strength

Strength

Strength

B class splice length of foundation, pillar, beam, wall(SD400)

※When using SD500 rebar(fy=500N/㎟=5,000kgf/㎠), apply 1.25 times

③ Splice length of compression rebar

HD10

HD13

HD16

HD19

HD22

HD25

HD29

HD32

Rebar

24N/240kgf/

27N/270kgf/

30N/300kgf/

35N/350kgf/

40N/400kgf/

510

670

820

970

1410

1600

1850

2050

670

870

1070

1260

1830

2080

2410

2650

490

630

770

920

1330

1510

1750

1930

630

820

1000

1190

1720

1960

2270

2510

460

600

730

870

1260

1430

1660

1830

600

780

950

1130

1640

1860

2150

2380

430

550

680

810

1170

1320

1540

1690

550

720

880

1050

1510

1720

2000

2200

400

520

640

760

1090

1240

1440

1590

520

670

830

980

1420

1610

1870

2060

General bar Upper barGeneral bar Upper barGeneral bar Upper barGeneral bar Upper barGeneral bar Upper bar

HD10

HD13

HD16

HD19

HD22

HD25

HD29

HD32

Strength

Rebar

fck = 21N/ = 70N/ (210kgf/ - 700kgf/ )

SD400 (fy=400N/ =4,000kgf/ ) SD500 (fy=500N/ =5,000kgf/ )

300

380

470

550

640

720

840

930

410

540

660

780

910

1030

1190

1320

(unit:mm)

Strength

④ Fixed length of tension bar which has standard hook fy=400N/㎟(4,000kgf/㎠)

※ When using SD500 rebar(fy=500N/㎟=5,000kgf/㎠), apply 1.25 times.

⑤ Fixed length and splice length of binded rebars.

Increase the fixed length and splice length of binded rebars as follows.

a) 3pcs binded rebars : increase 20%

b) 4pcs binded rebars : increase 33%

The splice of each rebar must not duplicated

HD10

HD13

HD16

HD19

HD22

HD25

HD29

HD32

Rebar

24N/240kgf/

210

270

340

400

460

520

600

670

27N/270kgf/

200

260

300

370

430

490

570

630

30N/300kgf/

200

240

300

360

410

460

540

600

35N/350kgf/

200

230

280

330

380

430

500

550

40N/400kgf/

200

210

260

310

360

400

470

520

50N/500kgf/

200

210

260

310

360

400

470

520

fixed length of tension bar

tension

or3db HD10 ~ HD254db HD29 ~ HD355db over HD38

min

(diam

eter)

(diam

eter)

destroyed section of concrete

Strength

tension

5. Criterion of Rebar bend-processing

1) Bending of main bar and leftover length

3d

3d

4d

30

40

50

60

70

80

120

130

12d

120

160

190

230

270

310

350

390

4d

60

60

70

80

90

110

120

130

Rebar size

HD10

HD13

HD16

HD19

HD22

HD25

HD29

HD32

Drawing

Leftover lengthRoller min. radius

Condition A Condition B Condition C

9.53

12.7

15.9

19.1

22.2

25.4

28.6

31.8

Rebardiameter

(unit:mm)

fixed roller center pole fixed roller center pole

(4d or over 60mm)

(ove

r 12d

)

2) Bending of stirrup, hoop and leftover length

3) Rebar processing form

Rebar’s hook(one-side, both-sides)

one-side

both-sides

2d

3d

20

30

35

60

70

80

9.53

12.7

15.9

19.1

22.2

25.4

6d

12d

60

80

100

120

280

320

6dor

60mm

60

80

100

120

140

160

Rebar size

HD10

HD13

HD16

HD19

HD22

HD25

Rebardiameter

Drawing

Leftover lengthRoller min. radius

Condition A Condition B Condition C

(unit:mm)

fixed roller center pole fixed roller center pole

U type

Closed type

Transformational

closed type

4) Slope dimension of rebar processing(hunch)

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

310

320

330

340

350

360

140

160

170

180

200

210

230

240

260

270

280

300

310

330

340

350

370

380

400

410

420

440

450

470

480

500

510

120

130

140

150

160

170

190

200

210

220

230

240

250

270

280

290

300

310

320

340

350

360

370

380

390

400

420

370

380

390

400

410

420

430

440

450

460

470

480

490

500

510

520

530

540

550

560

570

580

590

600

610

620

630

520

540

550

570

580

590

610

620

640

650

670

680

690

710

720

740

750

760

780

790

810

820

830

850

860

880

890

430

440

450

460

470

490

500

510

520

530

540

550

570

580

590

600

610

620

640

650

660

670

680

690

700

720

730

640

650

660

670

680

690

700

710

720

730

740

750

760

770

780

790

800

810

820

830

840

850

860

870

880

890

900

910

920

930

950

960

980

990

1000

1020

1030

1050

1060

1080

1090

1100

1120

1130

1150

1160

1170

1190

1200

1220

1230

1240

1260

1270

740

750

760

770

790

800

810

820

830

840

850

870

880

890

900

910

920

940

950

960

970

980

990

1000

1020

1030

1040

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

1040

1050

1060

1070

1080

1090

1100

1110

1120

1130

1140

1150

1290

1300

1320

1330

1340

1360

1370

1390

1400

1410

1430

1440

1460

1470

1490

1500

1510

1530

1540

1560

1570

1580

1600

1610

1630

1050

1060

1070

1090

1100

1110

1120

1130

1140

1150

1170

1180

1190

1200

1210

1220

1240

1250

1260

1270

1280

1290

1300

1320

1330

6. Tying method of Rebar

When tying the bars, the hook is used in Korea and Japan.

While in other countries, the wrench is used.

Tying the bars requires many times of practice.

All the places that two bars meet are recommended to tie.

However, it is usually accepted to skip all other crossing point in case of light-loaded

bars.

There are several types of binding the bars such as cross tie, Saddle tie with twist,

wall tie and double string tie, etc.

1) Cross tieTies to fix the stirrup onto beam ties to prevent hoop from slipping down

2) Double string tieSame procedure when you use hook to tie the bars mostly used in Asian countries

applicable to many construction sites such as wall, slab, etc.

You must tie different tying each bars.

3) Saddle tie with twistTies the bars in high beam or wall to fix them firmly

or to avoid twisting off

4) Wall tie- The same procedures as saddle tie with twist and tie

it as the method of right picture

- Ties the bars that extend from the wall to keep the

required positions and distances between them

5) References① Every crossing point of the bars at the bottom span should be tied, and wound

more than 3 times.

② When tying the bars at the top span, tie the bar changing the tying direction(one

time to left and next to the right)

③ When tying the bars in a slab, you may skip every other, but it is better to wind the

hoop before tying the bars.

④ It is advised to wind the hoop 3 times at the important crossing point.

※ There are several kinds of ties, and in construction works, #20 tie is normally used

in folded state.

7. Bar support , Spacer

① Bar support is usually to hold the location of placed bars, and spacer maintains the

cover depth of a member as intended.

② In addition, they also prevent dispersions of located bars due to high impacts and

undesirable vibrations.

Especially in reinforced concrete, cover depth, which is one of the important

factors for durability, should be seriously considered.

③ Undoubtedly, bar support and spacer should be strong or even stronger enough to

to support the bar and endure high impacts

④ When metal is used to reinforcement, spacer must have special rust protection on

the portions nearest the face of the concrete by attaching pvc cap.

Area : 4m2 - 8EA

16m2 - 20EA

Bar Space - around 1.5m

(Closer than 1.5m at the end)

Install to top span,

bottom span, sides

By calculation if Mat

thickness is over 1,500

At the top and thebottom except sidebeamAlso on the sides in theside beam

At the 1st tie hoop in the top span In the middle of pillar in the middlespanless than 1.0m of pillar width 2EAMore than 1.0m of pillar width 3EA

At the first tie hoop in the top span1.5m from the top in the mid spanTransverse spacing 1.5mWithin 1.5m at the end

Bar Space - around 1.5m

(Closer than 1.5m at the end)

Bar 1pc(1.3/m2) per width by long,

each 1m at the top & bottom bar

RemarkQ’ty & LayoutType

Steel Reinforcement

&

Concrete material

Part

Foundation

Foundation Beam

Pillar

WallBasement

Outside Wall

Beam

Slab

8. Conventional processing work tools

Once the construction work is initiated, reinforcement needs to be manufactured,

several different tools are used depending on the type of work.

1) Types of conventional tools.① Bending die : die to bend the bar on

② Bender : bends the bars

③ Hammer : adds force to cut the bar

④ Lower cutting blade

⑤ Upper cutting blade

⑥ Mat plate to fix the cutbar

⑦ Various types of bar bender and bar cutter are available(see Chapter.3)

2) Preparation before reinforcement of rebar work① Fabricate the bar bending die (The height should be about 850mm).

② Prepare the power cable to connect the bending machine and binding machine

③ Prepare chalk or other writing instrument to mark the dimension.

④ Prepare the tools and bending die.

<Bending Table>

<Manual Bender> Prepare per rebar size

<Hammer>

<Manual Cutter>

<Mat> <Low cutting blade> <Upper cutting blade>

Bending PlateBending Pin

3) Tools needed if assembling doesa. Measuring tape ~ measures the dimension

b. Hook ~ a tool to tie the bar(usually used in Korea and Japan).

Wrench is used in Europe and South-East Asia

c. Conventional shearing machine ~ cuts a bundle of binding wires to bind the bars in

a beam, a pillar(divide to half) or a slab(divide to 3parts)

d. Plumb ~ using to assemble the pillar bar vertically

e. Bar-tying hook ~ ties #8 wire

※ Tools mentioned above are rather old type ones, and newly developed tools are in

the construction site now.

<Measuring tape>

<Inch Ruler> <Bar-tying hook>

<Plumb>

9. Point of conventional processing work

1) Marking the bending point (example : D10~D13 stirrup , hoop)Mark the bending point on the bending die. Be sure to nail the bending panel on the

bending die to fix it firmly.

2) Determining the location of the manual bender

Nail

Bar back-stopper pin

Working point

Be careful

Make space +20mm width from thebending start pin.

Keep the 1.5d of tolerance from the working point(in case of D10, keep the 15mm of tolerance)

Processed dimension

The space of working point must over 20mm

than using rebar.

The position of bender must have space of

20mm from working point to bender using to

head of handle. (install within eye shot)

3) Processing

Bend the bar a little more than intended angle.

Make sure that there is 20mm of distance between the tip of bender and bending

point.

The distance between these two points should be neither too far nor too close for high

bending accuracy.

With your left hand, gently push the bender outward to bend the bar, while you grab

the bar with your right hand to fix it firmly.

4) Posture and position of footIt is recommended that bending

direction should be from right to left.

The left hand that pushes outward to

bend the bar should be at the level of

your belt.

Your right foot just turns the direction,

while your left foot moves quickly to

bending direction(Weight shift along

bending direction)

5) Currently using machinery

General Bender TYB-D35

Mobile Cutter TYC-D29A

10. Calculation of the quantity of Rebar material

1) Extra of rebar

① In case of deformed bar, extra is 3% in general when including fixed & splice

length of rebar, however, it is proportional to bar size.

16mm or larger : more than 5% extra

3% of 100ton is 100×0.03 = 3ton

② Rebar calculation included extra 3-8% after calculating fixing & splice.

Therefore, those works will prevent from the reason of illegal construction

practices with correct quantity & regular position carryout of construction by

calculating bar-list with shop drawing.

③ If rebar will be processed in rebar processing factory , basically extra is as follows.

In construction work 3%, in engineering work 6%, support work 3~4%.

You have to consider the economical efficiency and construction carryout

efficiency in site after analyzing in advance about extra percentage per rebar size

by the criterion per construction carryout area.

2) Base plate(Footing)<Example : 1>

In 2000×2000 foundation, shown as above, requirement of bar includes 20pcs HD22

bars of 1,840mm (80(cover depth)×2(both ends) = 160mm is extracted from

2,000(original length of foundation), 2pcs D19 assist bars of 2,601mm(1,840)×1,414

( 2 ), diagonal direction) and 4pcs short diagonal bars(2 bars in each diagonal

direction) of 2,318mm(1,640(200mm is extracted from main bar length 1,840mm)×1,414 ( 2 ).

① HD22 1,840mm×20(foundation) = 36,800mm

Weight = 36.8m(36,800mm)×3.04(unit weight) = 111.872kgf

② HD19 2,600mm(long bar)×2 = 5,200mm

Weight = 5.20m(5,200mm)×2.25(unit weight) = 11.700kgf

HD19 2,310mm(short bar)×4 = 9,240mm

Weight = 9.24mm(9,240mm)×2.25(unit weight) = 20.79kgf

ⓐ Actual requirement of bar is ① HD22 = 111.872kgf

② HD19 = (11.700kgf+20.79kgf) = 32.49kgf

※ LOSS(left bar strip) : The original length of bar before cutoff is usually 8,000mm.

In case of ①above, 4pcs 1,840mm bars are produced and 640mm of bar strip is

left.

5 bars are needed for foundation, hence 640×5 = 3,200mm of bar strip is left. Its

net weight is 3.20m(3,200mm)×3.04(unit weight) = 9.72kg.

ⓑ Actual requirement of bar is 8m×3.04(unit weight)×5 bars = 121.6kg

<Example-1>

<Example : 2>

① What is the weight of D10 8m bar?

0.56kg×8m = 4.48kg

② How many D13 bars(8m criterion) in 2ton?

2,000kg÷(0.995kgX8m) = 251EA(standard is 240EA)

③ Arrangement in foundation (base plate F)

( All the unit in drawing should be in 'mm')

HD16 = 2,000-(80(cover depth)×2(both ends)) = 1,840 (cutoff dimension)

HD19 = 3,000-(80(cover depth)×2(both ends)) = 2,840 (cutoff dimension)

HD13 = 1840₂+2840

₂= 1840×1840+2840×2840 = 3,383 (cutoff dimension)

(Note. x₂= x×x, 10₂= 10×10 = 100)

Here, multiply unit weight and number, then net weight of bar is

HD16 = 1.84m(1,840mm)×1.56kg = 2.87kg

2,840 ÷ @200 = 14.2 → 14 ⇒ 14+1 = 15EA

2.87kg×15 = 43.05kg

HD16 rebar 200mm space

HD19 rebar 300mm space

HD13 reinforcement bar 3EA

HD19 = 2.84m×2.25kg = 6.39kg

1,840 ÷ @300 = 6.13 → 6 ⇒ 6+1 = 7EA

6.40kg×7 = 43.73kg

HD13 = 3.38m(3,380mm)×0.995kg = 3.36kg

Weight = 3.36kg×assist bar(3+3) = 20.16kg

※Among 6 assist bars, two(2) of them in 3,380mm and the other(4) in 12,320mm

(4x3,080mm : 300mm shorter)

Net weight is 43.05+44.73+21.60 = 109.38kg and add 5% extra, hence 114.84kg is

required.

3) Base(footing) and pillar

As various footing types like continues footing, single footing and mat footing, there

are many shapes of footing, that is, triangle, right triangle, square, rectangle, pentagon,

circle, multi-layer plate, etc.

In this book triangle shape footing and single reinforcement footing are dealt with.

In case of footing shown left cover

depth, the type of bar and the size of

bar should be considered.

In addition, the reinforcement at

footing-pillar junction should be

included here.

Before bar cutoff, the size of C1,

the area of main reinforcement, the

size of hoop and the spacing of

stirrup are all considered consulting

the bar list.

Calculation :

Footing shown left is in contact

with soil, hence cover depth is

80mm at each end(80×2 = 160 at

both ends).

160mm is extracted from footing

length 2,000mm, and this(1,840mm)

is divided with spacing 200mm.

Then 10 reinforcement(at every 9

spacing +1 at the end) is required

here.

Now reinforcement is in two

directions and therefore we need 20

reinforcements.

F1 plane

Section

cover50

cover80

HD22@200

HD22@200

D10@300

HD22-8EA

D10@300upper part, lower part @150

HD19-6EA

4) PillarSimilar to footing, there are many shapes of pillar, that is, triangle, right triangle,

square, rectangle, pentagon. circle, etc.

The worker is recommended to earn a lot of working experience.

① Calculation of pillar

In calculation, tie hoop, stirrup, main bars

in column and the others should be

included here.

First extract cover depth from hoop size

(400mm), and cover depth in the basement

and above the ground should be different.

Net length cover depth 400 - (40+40) =

320 (dimension)×4(4sides) ⇒ 1,280 +

100mm of hook then, cutoff length is

1,380mm.

Since net length of hook is 100mm, only

100mm of extra length is added here.

If the bar size is D10, one end is hooked

in circular, so 2 times of bar diameter

(20mm) is extracted here, As 5 hooks are

needed and hook length is 100mm at each

end(200mm in total), 80mm is extracted

from 100mm.

Then this 80mm is added to produce

200mm of hook length.

D10@300

HD22-8EA

D10@300upper part, lower part@150

5) Calculation of main rebarIf you will carry-out with 8,000mm rebar including both fixed length(anchor) from

total length of 1 span , you just add the splice length from rebar diameter to use.

Example) Total length 62,000mm + both fixed length(anchor) 1,000mm = Gross Total

63,000mm. When using HD19 rebar, splice length is 19×40d = 760mm. Rebar

8,000mm - splice length 760mm = 7,240mm. Gross Total 63,000mm ÷ 7,240mm =

8.7 piece (long bar 8piece & rest 5,080mm) Above splice length is 5,080mm

including anchor.

You can calculate it as above , but you have to carry-out the splice position as soon as

closely by calculating several methods if spice position is not fit well.

END

long bar processing splice rebar long bar

outside end

outside end

end top-bar center top-bar in span

end top-bar center top-bar in span

CENTER<Sample of processing>

6) Calculation of top rebarPlease refer to the method in construction site as follows because it is very difficult to

explain in theory.

If 1 span is 8,000mm, 4,000mm will be center part and add 40times(40d) + rebar

thickness is the length of top rebar in center part & end.

You cut as 4,000mm +760mm = 4,760mm.

※ When assembling current processing status , center part is from beam to upper part

rebar splice position and end is lower part rebar splice position if splice rebar 2 pcs

4,580mm + long bar processed 1pc as upper part rebar and splice rebar 1pc

4,580mm + long bar processed 2pcs as lower part rebar will be used.

And so, you assemble it mutually crossed and upper part is 2 bar from 3 bar from

splice position.

7) Calculation of hoop① If pillar size is width 400mm length 500mm, actual processing size is 320mm,

420mm except cover 40mm each(both 80mm).

② When processing hook by hand, it will be included 40mm from total length.

When using Taeyeon's bending machine, it will be included 50mm from total

length .

③ Cut size : (420×2)+(320×2)+50 = 1,530mm

※ Example of hoop usage : To avoid wrong bending of main bar and to restrict inner

concrete , you maintain the space and no problem to assemble with 135°hoop at

one side.

coating thickness 40

process size

8) Calculation of stirrup① If beam size is length 500mm , actual processing size is 420mm , 420mm except

cover 40mm each(both 80mm). If beam size is width 300mm , actual processing

size is 220mm , 220mm except cover 40mm each(both 80mm).

② Including hoop 50mm , you can use Taeyeon's bending machine.

③ Cut size : (420×2)+(220+50(hook)=1,100mm

※ Example of stirrup usage : To surround tension & compression bar and to restrict

inner concrete , you maintain the space and bend with over 135°as stirrup end

length.

Taeyeon bending machine will be processed 90°or 135°with free by

manufacturing of special tool & electric circuit.

9) Fact of processingAccording to rebar thickness and to bending angle , 2 times of rebar thickness will be

used because of bending by circle of bending part than the length per actual straight line.

<Tolerance of rebar process size>

Item

stirrup, tie hoop

below HD25

over HD29

length after processing

Symbol

A, B

A, B

A, B

-

Tolerance( )

5

15

20

20

mainbar

Drawing

CENTEREND Process size

10) Changed size if it bent 1 angle per specificationWhen bending 1 angle, rebar D10 will be increased by 2cm each.

When bending 1 angle, rebar D13 will be increased by 2cm each.

When bending 1 angle, rebar D16 will be increased by 3cm each.

When bending 1 angle, rebar D22~25 will be increased by 5~6cm each.

Because bending part will be bent like R type, rebar will be less used per rebar

diameter.

Regarding processed rebar, it will be less used also by measuring with outside

diameter size.

Note) Process size must be outside diameter size of processed rebar.

11) Tolerance of processed size

processed sizeothers

stirrup, tie hoop, spiral rebar

under D25 of deformed bar

D19~D41 of deformed bar

total length after processing

Tolerance( )

5

15

20

20

Item

If actual cut size is D10,

(42×2)+(32+8(hook)) = 124cm

11. Foundation(Base) rebar arrangement

1) Foundation(base) workIn foundation work, the lean concrete underneath the footing concrete, is very

important.

Without it, constuction site, on which a building will be raised up, it would not be

clean and stable disturbing construction work.

Be sure to make lean concrete working mat having at least 50mm of thickness.

If F.L. of lean concrete is not fit, there are difficulty in fix S.L.

2) The height of spacerBar spacer is used to maintain the arranged bar balanced.

When arranging the bars or flooring, stones and bricks can not be used to support

them.

You have to prepare spacer in advance because there are high possibility of unbalance

when using stones or bricks to level the ground.

(in case of spacer height lean concrete top is 60mm)

< Cover thickness of rebar >

part to not contact land

lean concrete

part to contact land

over 80mm of cover thickness infoundation rebar

over 50mm of cover thickness than pilehead on base concrete

※ The reason that the top of piles is embedded into foundation is that , in case of an

earthquake , the pile causes bending fracture.

Especially , when the ground is unstable , there should be specified directions on

the drawings.(in case pile cover bending moment & compresssion or cover tension

properly only)

3) Independent Foundation(Single Footing)Usually in double footing and floating foundation , remained bar length is bent up and

down to splice them together as depicted below.

However, the remaining parts of the bar can be cut off to reinforce the foundation.

6-D13(circular arrangement)

HOOP D13@150×4

2 times ofpile diameter

PC or PHC PILE

when securingsplice length

In case of belowsplice length

standardhook

<In case of securing splice length> <In case of not securing splice length>

Hole closure

Fillup CON’C

PC Steel wire

(foundation CON’C)

4) Foundation(base) pillar tie hoopThe main purpose of the tie hoop is to restrain the transverse load in order to relieve

vertical load into pillar.

Even though foundation concrete has capacity to support the loads from the pillars, tie

hoops help main bars be fixed at which they should be and it is important job.

※ The tie hoops at the bottom hold the bars of the pillar in lean concrete and marking

on the mould form is compared with drawing to ascertain the center of the pillars.

5) Foundation(base) upper-support(Wooma) rebar - Foundation thickness : below T=1,000mm for HD16, over T=1,000mm for HD19

space should be @1000-@1500

<Before reinforcement>

<Foundation plate>

<After reinforcement>

slab

main bar

tying

MAT

pillartie hoop should be@300 distance perthe drawing regulation,

bottom tie hoop

pillar

marking

eccentric

pillar location

The outer pillar must check main bar line.

footing

spacerlean concrete

12. Pillar rebar arrangement

1) Indication of pillar(C)Main bar drawing - It indicates the length of span by the criterion of pillar and wall,

etc. and indicates the position of pillar & wall.

500×500 - actual size of concrete

8-HD19 - 8pcs of HD19mm rebar

D10 @250 - install per 250mm of HOOP distance

D10 @250 - install per 250mm of DIA HOOP distance

※ Be careful of this point if there are rebar quantity's differences according to pillar

assembly x0, x1 or y0,y1 direction.

<Example>

C - pillar

BC1 - #1 underground pillar

1C1 - #1 first-story pillar

2) Indication of floor

2SL(upper concrete)

2FL(upper part’s closing condition)

1) GL - GROUND LEVEL

2) FL - FLOOR LEVEL

(ground level per floor)

3) SL - SLAB LEVEL

(upper part of structure per floor)

Height of floor

3) Sequence of pillar assembling

< Stand the same to one direction if each side is even & odd. >

< Stand the same to all directions if each side is odd. >

< Stand the same to diagonal direction if each side is even. >

4) Tying method of pillar① Even the tiny little requirement for the construction should be taken into

consideration.

Keep the pillar reinforcements vertically and splice the bars 3 times.

Upper and lower parts of the reinforcements should be cross-tied.

② When tying the corner of tie hoop, it is better to wind the tying wires changing

directions up and down to let it not to be hung down.

It is also recommended that worker wind the tying wires at least one time in

advance to hold the main bar to its original position.

③ Tie bar for assisting pillar should be at every distance to install tie hoop .

main bar

Diamond type General type

tie bar

④ Bind the tie hoops clockwise(as shown below) and spacing at the top and bottom

levels of vertical reinforcement should be within of hoop spacing beginning at

50mm from the bottom of the floor.

5) Position of pillar tying

① In pillar bar slice, follow the instructions on drawings in order to splice them

adequately, that is, if not, the length of reinforcement is not fit for column with the

reason that usual 8,000mm bar is cut into two 4,000mm bars to splice.

[Note]

It is desirable that reinforcing bar should be in a variety of sizes, but 8m bar is usually

available in the market.

In other words, if you need a bar other than 8m in size, you should give a customer-

order for it, which does not go well with economical strategy.

Reinforcing bars from D10~D16 do not have much problem in using them as

reinforcement for slabs or bearing walls. We have some advantages here.

Bar loss and the frequency of splice will be decreased if using bars of 8m ~ 12m

length by mixing.

good location of splice

available location of splice

bad location of splice

② Splice of pillar and pillar

6) Cross assembling of pillar and beam(only for outer pillar)① Don't fill up tie hoop to assemble beam the crossed part of pillar & beam.

In this case , there are difficulty in carrying out the construction but you must fill

up tie hoop of outside.

Especially, you should prevent from the protruded main bar by filling up tie hoop

on outer pillar and edge pillar.

under 75 over 75

Dowel rebarmax. 150

max. slope

slope rebar splice using dowel rebar

fixing

splice

max. 150

splice/fixed length of tension bar

pillar pillar

beam carry-outof construction

from currentrebar arrangement

tie hoop

② In case over 600mm of pillar size , you should fill up support tie hoop by shop

drawing.

You should get rid of support tie hoop in order to worker's entrance to pillar tube

to connect #8 wire for working of pillar outer appearance.

After this, the worker should not forget to bind the assist wire before he gets out.

※ In case the splice length for pillar splice is shorter than required, be sure to destroy

the concrete to maintain splice length but it is impossible possibility to execute

actually.

Therefore, you should check the availability of welding splice, compressed splice,

mechanical splice.

7) Correction of pillar① Bend the bar gently at a very low level

② Pillar correction angle should not exceed of overall angle

③ Heat should not be added to correct the main bar because it makes the strength of

rebar, just destroy the part that needs correction and bend it of overall angle.

④ Destroy the part that needs correction and modify it.

These are 2 cases of correction depending on correction angle.

ⓐ When the correction grade is low

ⓑ When the correction grade is higher than , change the bending angle to

and cover the pillar as thin as possible.

If corrected angle is about ,insert the bar into pillar after bending.

Bending after concrete work.

Increase to minimum pillar thickness

Pillar rebar protruded to outside.

8) Detailed drawing of pillar and beam rahmen(arrangement)① Don't apply compression splice length except pure compression material.

Regarding bending material , apply B class splice for tying near max. stress point

and apply A class splice for the rest block.

2nd

floo

r HO

fixe

d le

ngth

A class tension splice

A class tension splice

tension splice(over B class splice length)

tension splice

space

The fixation of upper bar calculates fixed length from the mainbar bend area of pillar’s upper part, not from the inside of pillar

When the beam is arranged, the bottom bar should be all tied,and the stirrup upper binding supported by spacer should betied 2,3 times tightly.1s

t flo

or H

O

main head

② Apply to anti-earthquake

In case all plane of pillar have beam

Lo max. size of pillar section

Lc/6

45

In case some plane of pillar has beam(ground outside pillar)

So 8db(main bar)

24db(hoop bar)

1/2(min size of pillar section)

30

slab rebar

beam lowerpart bar

max

.

max

.

13. Beam rebar arrangement

1) Principle of beam rebar arrangement① Calculate the size and depth of beams according to the drawing and arrange them

in a suggested order, that is, exterior beams and big beams(G) & deep beams first

and then binding small beams(B beams) later.

② Supervisor has to check if the bar used at the top span meets the requirement on

the drawing.

Shorter bar than required might be used to save cost when the span is longer than

8,000mm, the bar standard.

③ The bar might deflect from undesirable vibration when placing concrete if the

double reinforcement or top end bar are tied with tying wires.

To prevent this, 3 pieces of stirrups are used to tie the bars at the top and as many

pieces to place double-leg bar & top bar on the bottom bar.

④ Cap tie bar should carry out 1 by 1 at least.

※ The 1st stirrup should be arranged with the space 50mm from the perimeter of

side pillar.

@/2 or under 50mm from side pillar @/2 or under 100mm from side big beam

<The height will be changed by th rebar size>

Stirrup:end support(S.T.)

1st stirruparrangement besideof pillar’s main bar

1st stirruparrangement besideof big beam main bar

big beam

Center support(S.T.)

※ The splice for upper part rebar of beam's end and lower part rebar of beam's center

apply tension splice length.

※ Apply the above except the case of marking separately on beam chart.

※ S1-S4 : stirrup distance

2) Types of stirrup

Ldh

S1 S2 S3

5050

end0.25L1

center0.5L1L1 L2

end0.25L1

end0.25L2

center0.5L2

50

S4

12db

0.3L1 OR 0.3L2 0.3L1 OR 0.3L2

min 15㎝ min 15㎝ or continuance min 15㎝ or continuance0.125L1

0.125L1 0.125L1L1 L2

0.125L2

<Main bar arrangement>

<Distance of stirrup>

- beam without cap tie bar- beam to be arranged by front end without twisting- beam without anti-earthquake plan

① slab on both sides ② slab on one-side ③ no slab on both sides

<a> Open type

<b> Closed type

middle/big value

middle/big value

3) Position of beam tying(splice)

※ Splice location : diagonal line

① Calculation of bender

When bent bars are used to reinforce beams, bending point of the bar is usually

calculated as distance from the center of the pillar.

However, it is formal to divide it into 4 parts from the end of beam reinforcement

to the other end.

- beam with front end and twist- in case of anti-earthquake plan

wall girder

pillar

over

30c

m

over

45c

m

splic

e ag

ains

t tot

aldi

stan

ce o

f mem

ber

② An example for processing

Anchorage(fixed) bars are classified as the top bars and the bottom bars, when the

former have tensile loads and the later have compression loads.

Therefore, the top bars and bottom bars set fixed splice length with same method

because it has difficulty in working separately for processing and

assembling.(criterion of concrete structure plan)

In a real construction, 40d is used for both of them for convenience sake.

③ Cover depth of beams

ⓐ Stirrup with spacer should be tied several times.

ⓑ Pay attention when arranging reinforcements in order to have enough cover depth.

4) Bending position of bender (classification of tension & compression)

※ Using the bent bars in beams is Japanese style, while cutoff bar is now in common.

spacer

Y beam

Y beam X beam

X beam

Ten

sion

fixa

tion

Tensionfixation A class tension splice

A class tension splice

bent bar

penetrationof bent bar

top bar

(Top floor)

(General floor)

bent bar

height 40

coverthickness 40

5) Beam rebar arrangement(CUT TYPE)① In case of beam

② In case of girder

Note

1) * : apply general bars splice length(A class splice) as standard splice length &

fixed length of rebar(22page 6)) for above size

2) ** : fixed as standard hook form about center part bottom bar's 25%

3) splice length according to splice position of rebar arrangement

- tying on upper part rebar(beam) block : apply A class tension rebar splice

tying except upper part rebar(beam) block : apply B class tension rebar splice

- tying on lower part rebar(beam) block : apply A class tension rebar splice

tying except lower part rebar(beam) block : apply B class tension rebar splice

0.3L or 0.3L1 0.3L or 0.3L1

big value big value

0.3L or 0.3L1 0.3L or 0.3L1

big value big valuestandard hookfixed length

6) Beam rebar arrangement by using stepped pulleyThe types of step are classified as planar step, elevated step, step in material

according to their shapes.

In each case, arrangement is in vertical or in horizontal.

If the worker has no choice but to bend the bar, bend it at low grade.

When the mid span of a beam has steps as shown below left, the bar might be

necessarily bent, which is quite undesirable.

The load tends to straightly pass through.

If pulled out, the bar does not straighten as it looks.

Far from straightening, it will break or fracture.

Needless to say, it is recommended that the worker cut the bars and arrange them

separately, as depicted below.

tension fixed lengthtension fixed

length

breakable due to the tension

Wrong method Correct method

7) Hunch beam① Bend the bars at the bottom in a hunch former and anchor them onto the pillar.

② Bend a half of the bars at the bottom to let the anchorage length penetrate the pillar

and anchor near the hunch point.

③ One size bigger stirrup should be used at the hunch point.

8) Pillar-holding rebar (Butterfly stitching rebar/Stirrup closing rebar)① As few drawing gives direction on pillar-holding rebar, it is common to use it at

every third stirrup.

If not, all junctions of pillar-holding rebar should be confined per every stirrup.

S.T. one size bigger stirrup

stirrup

processing

(current) (revised)

<butterfly stitching rebar>

Better if one end hooked 135°

9) Symbol of beam·Continuous end of beam

·Center of beam

·Exterior of beam

·Interior of beam

·Outside of beam

end stirrup:arrange 200mm distance-D10upper part : HD22-3

end top bar : HD22-2

EXT(exterior) CENT(center)

400×500(stirrup process size : 320×420)

300×500(stirrup process size : 220×420)

stirrup : arrange 200mm distance-D10

tension splice(B class splice)

upper part bar : HD22-3EA

END(end)

END(end) CENT(center)

center stirrup-arrange 250mm distance-D10

center top bar : HD22-2

lower part bar :HD22-3

support bar : HD13-2EA

support bar : HD22-3EA

lower part bar : HD22-3EA

10) Detailed drawing of beam rahmen(arrangement)

horizontal rebar : HD10@200(arrange 200mm distance-D10)

vertical rebar : HD10@200(arrange 200mm distance-D10)

400×500(stirrup process size : 320×420)

400×400(hoop process size : 320×320)

tension splice(B class splice)

Each floor bottom structure plane figure symbol & beam chart symbol

END(end) CENT(center)

tension splice

hoop : arrange 250mm distance-D10

main bar : 10-HD19

support big bar : arrange 250mm distance-D10

※ You should check pillar size & rebar Q’ty per each floor, and also arrange after

checking rebar Q’ty & drawing of outer pillar’s front and side.

14. Caution if beam assembling does

1) Lean concrete working mat beneath the underground beam helps to ease the

arrangement of bars.

If gravel or brick is used to support underground beam, the reinforcement in the

beams might deflect to break the top of stirrup.

Furthermore, it might disturb the arrangement of reinforcement at the bottom of

beam and so cover condition of vertical & horizontal is not fit.

Stirrup as criterion must tie without breakage 2 times, 3 times when tying upper

part.

2) When placing the concrete, it is usual to place concrete again after curing, and

repeat the same procedure.

During this procedure, protruded bars may become damaged or underground beam

and floor slab may not fit very well because of shrinkage.

Also, it will be not cleaned well because of dust if you will do concrete job with

arrangement of ground slab without neighbor ground cleaning completely.

3) In the author's view, it is recommended that, after completing lean concrete

working mat, the worker build up the fence around the reinforcement zone, in

which the bars are arranged, to cast in concrete at the same time.

It would be quite efficient since 2 cast-in procedures can be reduced to 1 procedure

and it also saves time and cost considering input of material & carpenter.

100mm from pillar rebar

breakable of stirrup tying

spacer

all bottom bars should be tied

4) Regarding beam rebar arrangement by using stepped pulley , you must be

processed separately because the continuity of rebar arrangement is different for

lower part rebar , and pay attention to the difficulty in entering of G bar & G bar

when assembling B(small beam) lower part rebar.

15. Tying position(splice location) of underground tie beam

Example : actual fixed length of D22 is 770mm

if pillar size is 500mm, actual anchorage length is 370mm

p.s.) Fixed splice length and standard hook(anchor) length refers to concrete structure

plan’s criterion

<Tying position in case footing slab get forced from weight of top>

<Tying position in case footing slab get notforced from the soil>

<Arrangement method in case footing slab getforced from the soil>

tension fixation

tensionfixation

<Arrangement method in case footing beam getforced from the soil>

<Tying position in case footing slab get forced from the soil >

pillarmainbar

16. Calculation of beam rebar

Bent bar that is placed above(up) and below(down) of beam is Main-Bend, and bent

bar that is placed on both sides of beam is Side-Bend.

Main-Bend

※ Hunch angle should not exceed 45°(bent angle is "bent angle")

Side-Bend

Calculation of all 2 types of bent bar is the same except the way of extracting pure

height of main bar from stirrup height(thickness).

Either span of , from one end can be accepted depending on their uses.

1) Calculation of up-down bend(Main-Bend) in the beamProvided that the height of beam is 500mm , the length of span is 8,000mm and the

size of pillar is 500mm , then the steel requirement is as follows.

① 8,000mm-(500mm-40mm-40mm)-(500mm-40mm-40mm)=7,160mm

7,160mm÷4=1,790mm Hence, the value of ① is 1,790mm

beam height ST height

100 cover

inner length left rightup·down cover up·down cover

② 1,790mm×2=3,580mm(value of ②) are extracted hunch length from inner length

③ Extract cover depth from 500mm(beam height : 420mm) and multiply this by 1.4,

and again extract 20mm(D10 diameter), [500mm - (40mm×2)]×1.4 - 20mm =

568mm, and then we have 568mm.

※※ Calculation of hunchHunch = the height of stirrup×1.4 - 20(bar diameter of top and bottom stirrup×2)

④ fixed length is 40d in usual, hence provided that used bar is HD19,19mm×40d=760mm

The length of anchor ⑥ is 760mm- pillar fixation 400mm=360mm

⑤ 400mm + ① 1,790mm = 2,190mm

⑥ 400mm is the rest value except cover 100mm from width of pillar.

The length indication when spreading above calculation is as follows.

※ Total length 9,806mm for 8,000mm bar, the splice length is 2,566mm.

(example) 9,806mm-8,000mm=1,806mm, Total length is 1,806mm+760mm(splice

length)=2,566mm

2) Calculation of side bend in the both sides of beam

beam height 280(ST height)

actual height

END CENTER

100 cover

① 8,000mm - (420mm - 70mm - 70mm) - (420mm - 70mm - 70mm) = 7,440mm,

that is, 8,000mm - (280mm×2) = 7,440mm, and then 7,440mm× = 2,232mm.

② Center point is , and then 7,440mm× = 2,976mm.

③ Hunch length is calculated from hunch height multiply 1.4.

280mm×1.4 = 392mm, hence hunch length is 392mm.

④ Fixed length is 40d in usual, hence provided that used bar is HD19, 19mm×40d =

760mm is fixed length , 760mm - 400mm(pillar fixed) = 360mm(anchor value⑥)

value① 2,232mm + 400mm = 2,632mm(actual distance of end upper part)

⑤ Cover depth(100mm) is extracted from pillar size(500mm)

500mm - 100mm = 400mm

If the bent bar mentioned so far is straightened in a line, it is like shown below.

※ Total length required is 9,744mm and provided that the standard bar length is

8,000mm, we need to splice here and the splice length is 2,504mm.

example)

9,744mm - 8,000mm = 1,744mm

1,744mm + 760mm(splice length) = 2,504mm(total length)

※ To summarize, Main-Bend's return bend point is lx point, Side-Bend is lx

point, you can find the bending to exterior side(to center part).

inner length ST height left right(up·down distance)

side-bend height

totallength

17. Slab rebar arrangement

1) Slab rebar arrangementSlab type classification

2-way slab rebar arrangement method 1-way slab rebar arrangement method

Slab main bar arrangement type classification

Bent bar type

- Union type of outer beam and slab

- Union type of outer wall and slab

(ly < 2lx Type) (ly < 2lx Type)main block main block

90°standardhook

wall

0.3L or 0.3L1

0.3L or 0.3L1 0.3L or 0.3L1

apply A class splice of tension bar if upper part bar tying onlocation (apply B class splice of tension bar on the rest location)

apply A class splice of tension bar if upper part bar tying onlocation (apply B class splice of tension bar on the rest location)

big value

big value big value

big value

0.3L or 0.3L1

ⓑ Cut bar type

- Union type of outer beam and slab

- Union type of outer wall and slab

90°standardhook

wall

0.3L or 0.3L1

0.3L or 0.3L1 0.3L or 0.3L1

apply A class splice of tension bar if upper part bar tying onlocation (apply B class splice of tension bar on the rest location)

apply A class splice of tension bar if upper part bar tying onlocation (apply B class splice of tension bar on the rest location)

big value

big value big value

big value

0.3L or 0.3L1

③ Rebar arrangement details of slab stepped pulley

In case H < 75mm or t/4

In case t/4 < H < t and H < 150

In case t < H < 2t

※ In case H > 2t, consult with structure planner.

※ In case there are stepped pulley on slab center part, you should fix by using 90°standard hook for slab lower part rebar.

④ Slab and wall union details

splice length of tension bar

1-HD13 or over main bar

slab arrangement distanceusing closed type STR

4-HD13 or over main bar

splice length of tension bar

standard hook

standard hook

H≤75mm or t/4

outside inside

wall slab

90st

anda

rd h

ook

⑤ Tolerance range of slab , beam , pillar , wall rebar arrangement

ⓐ Allow to 6mm as tolerance of D in case under 600mm of slab, beam, pillar,

wall.

Allow to 10mm as tolerance of D in case over 600mm of slab, beam, pillar,

wall.

ⓑ Allow to 50mm as tolerance in case bent point or end point of length

direction rebar(but, except for end of concrete)

ⓒ Big bar of pillar and stirrup of beam can get the space till 0~6mm as space

length from main bar

cove

r thi

ckne

ss

cove

r thi

ckne

ss

2) Principle of rebar arrangement① The worker measures the real length between beams and arranges the

reinforcement bars consulting the drawing, main bars in the short direction and

sub. bars in the long direction.

② Bent bars at the top should be extended into the exterior beam reinforcement, and

be sure for the bars at the top and bottom to be hooked and tied considering tensile

and compressive force to slabs.

It is not allowed if you put on slab upper part rebar as it is or put into the beam

under 10D of rebar thickness of lower part rebar.

Slab bar arranges over 80mm space from side of beam bar. (There are no need to

fixing by bending if you can get fixed length from end of beam)

※ The arrangement in slabs should be in accordance with the drawing and be sure

not to bend if it is a web reinforcement.

③ It is quite advised to use spacer and bar support to keep the required shape and

strength, and tie the reinforcement every other grid.

The placement of concrete should be conducted after all the reinforcements and

ties are assured.

④ In case the thickness of slab is 120mm, the height of bent bar should be 60mm.

Use bar support in order to maintain the space between bars at the top and bottom

and then the distance will be correct.

Lower part bar will be worked by maintaining cover with spacer.

⑤ Tie the bars at the top and the bottom irrespectively.

Tying the bars is conducted in alternate and do not let the tying positions coincide

with each other, so that the bars at the top sustains upper loads and the bars at the

bottom handles undesirable loads.

3) Calculation of slab plateIt is wrong method in case you cut the length of cut bar(top point) in advance by

calculating point from center to center of beam.

Therefore, you determine the end by calculating as the criterion of short LX from

the rest plate by deducting both width parts.

※ When bending in slab, using the hunch former will enhance the accuracy and

workability.

Hunch former can be made with bars on construction site.

If the bar is bent with hands, the length and the height of hunch will different

whenever it is made.

Please work with hunch former because bent bar decline to left/right side if you

bending too slantly to fit the height with hunch angle 45°.

L calculate end

4) Sequence of slab rebar arrangement

※ Phenomenon in case there are no formal arrangement of slab

① In slab arrangement, bent bar should arrange (bend on return bend point) by above

procedure. But total length is not fit by coming inside as diagonal length to bend

after assembling upper part bar, lower part bar completely when using arrangement

method on construction site regularly.

② In formal rebar arrangement, it consists of main bar, sub bar(upper part 2 layer,

lower part 2 layer). But it has difficulty in maintaining rebar up/down distance by

folding top sub bar over main bar and sub bar(upper part 3 layer, lower part 3 layer).

<A-A section>

① lower main bar of transverse direction

② end lower part bar of longitudinal direction

③ end upper part bar of longitudinal direction

④ bending after tying

⑤ center lower part bar of longitudinal direction

⑥ end upper part bar of transverse direction

⑦ bending after tying

⑧ upper part cut bar of longitudinal direction

⑨ upper part cut bar of transverse direction

upper part bar(TOP)

lower part bar(BOTTOM)

inne

r end

upper part

lower part

end inner endcenter

cent

eren

d

5) Sequence of base slab rebar arrangement

※ Arrange the bars in numerical order suggested above.

※ Use spacer and bar support to install within 1m each transverse & longitudinal

direction for upper & lower part rebar and also install to 1st rebar for each end.

<A-A section>

Lx/4Lx/4 Lx/2inner endend center

Lx/4Lx/4 Lx/2Lx

Lx/4

Lx/4

① lower main bar of transverse direction(end center part)

② center lower part bar of longitudinal direction(center part)

③ tying bent bar of longitudinal direction④ center upper part bar of longitudinal direction⑤ tying bent bar of transverse direction

tying bent bar of longitudinal direction(bend opposite side after tying)

⑥ end lower part bar of longitudinal direction bending bent bar of transverse direction(bend opposite side after tying)

⑦ end upper part bar of longitudinal direction⑧ center upper part bar of transverse direction⑨ end upper part bar of transverse direction

upper part bar

lower part bar

underground tiebeam obtains thecover thickness over 80mm for

arrangement of slab lower part bar

inne

r end

cent

eren

d

fixed length of tension barwhich has standard hook

6) Check after assembling slabAfter construction of slabs, the supervisor should check following matters.

① Are pillars of adjacent floor(usually upper floor) well positioned having intended

dimensions?

② Is cover depth of slab well distributed and balanced?

③ Is there any abnormally inclined bent bar?

④ Are spacer and bar support rightly installed to be strong bar splice all right?

⑤ Is slab Bar splice all right?

⑥ Is reinforcement at the opening acceptable?

⑦ Enough splice length to the next floor?

Any dissatisfaction with items above will lead to poor construction and safety

problems.

In particular, if it is the matter of columns, it is very difficult to rebuild it and has poor

appearances.

And it is also an economical burden to the builder.

7) Position of slab tying

direction directiondirection direction

tension splice

good position for tying

8) Understanding of slab drawing

① If all bottom of slab symbol is different per span, rebar arranged to main bar

direction for short side. If span will be reverse direction, you should check in

advance because main bar will be reverse direction. (especially in case slab

stepped pulley)

In the plane drawing of open part, you can see the inside as above when you see to

arrow direction with dotted line and also you can know in detail with chart about the

size of beam and also which rebar will be installed.

Especially, you should check section drawing well.

If you cut plane, you can see elevation(verticality), reversely if you cut elevation, you

can see plane.

In any drawing and plane, we mark section for the part to understand difficultly to

help you for processing and arrangement on right section of drawing.

It is best way to get the training of supervisor and you must study symbols on

drawings.

down 200mm to right side fromleft side of solid line

open part plane figure

plane section

cross section

SLAB DOWN

② 1S1(1 means 1st floor , S means Slab , 1 means #1(type))

※ Reference : dot line means lower part rebar , solid line means upper part rebar

③ Detailed drawing of beam and slab's connected part

※ Author's viewpoint : If you did not study shop drawing completely, you will solve

question if you will start construction by discussing to check wrong one after

visiting construction site after checking the drawing under construction over

80%.(especially, carpenter's process is over 80%).

Classification

1stfloor

Symbol

1S2

1S1

Type

B

A

Thickness

150

120

X1

HD10@200

HD10@250

Y1

HD10@200

HD10@300

X2

HD10@200

HD10@250

Y2

HD10@200

HD10@300

Longitudinal direction(Ly)Transverse direction(Lx)

slab thickness 120mm slab thickness 150mm

Y2(lower part bar)HD10@300 distance

Y2(lower part bar)HD10@300 distance

Y1(upper part bar)HD10@300 distance

Y2(lower part bar)HD10@250 distance

X2(lower part bar)HD10@250 distance

Y1(upper part bar)HD10@250 distance

X1(upper part bar)HD10@250 distance

SLAB upper part rebar doesn’t tie to beam main bar

Y1(upper part bar)HD10@300 distance

9) Principle of ground slab① Bar arrangement in the floor slab begins 50mm from the slab wall side having

constant spacing.

② Arranged bars should be strong enough not to deflect when a person steps on

them.

Unscreened gravel and bricks can not be used in order to keep spacing between

bars, and specified bar supports and spacers should be used to maintain the

dimensions and shapes of the slab as intended.

③ After arrangement, single bar might need to be cut off with oxy-acetylene cutting

in the requirements of collecting well or manhole.

In such cases, there could be cracks at the end tips of bars, and therefore more

reinforcement and splice should be adopted here.

※※ The most important thing in floor slab - Base Tamping

▶ After shovelling , the land must be tamped with vibration compactor.

▶ Even though drawing does not refer to tamping, the worker must bear it in

mind as specification indicates.

However, it is real situation that there are little workers to keep it.

▶ Both the client and the builder should hold it in common that even the neglect

of construction rules and standards will lead to fatal harms to both of them.

tension splice tension splice

18. Wall rebar arrangement

1) Sequence of rebar arrangement① 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.

② Placement sequence of wall suggested below

③ 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.

main barwidth fixing bar sub bar

reinforcement bar

width fixing bar

2) Principle of assembly and rebar arrangement binding

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.

① Begin the placement of assist bars from 100mm above the floor place the stirrup

② 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.

corner

saddle tie with twist

it should be tied with 1,2 timeswound depending on @ distance tying to maintain distance of upper part

3) Crosspoint main bar and horizontal rebar arrangement

<Single arrangement>

<Single and double arrangement>

<Double arrangement>

<Straight wall>

wall horizontal rebarU bar

U bar

U barwall vertical rebar

wall horizontal rebar

wall horizontal rebar

4) Details of wall on top floor

※ 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.

<Top floor outer wall> <Top floor inner wall>

90°standard hookroof floor slab

slab upper part bar

slab lower part bar

tensio

n sp

lice

over 150

wall vertical barwall horizontal bar

wall

roof floor slab

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.

※When the inserting bars as arranged straight bar are inserted at the underground beam

※ 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.

<resistance wall> <underground retaining wall>

<stirrup closing bar>

fixed length no problem if fixedlength will be obtained

tensionsplice

tensionsplice

pillar pillar horizontal bar vertical bar

good position to tie

B class tension splice

inside

inside

outside

outside

outs

ide

insi

de

foundation beam

beam

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

19. Other rebar arrangement

1) Stairway rebar arrangementⓐ Place the bars in the suggested sequence according to drawing.

Double reinforcement should not be bent.

ⓑ There are a few extended bars from pillars or beams to the stairs .

You should assemble by using standard hook(anchor) in case of assembling to cut

without bending bars for this working.

Example)

ⓐ Place the bars in the numerical order shown below

ⓑ Bend ④ bars after binding

ⓒ Cut ⑥ after binding

※ Special notice for the bar-arrangement

tension fixation

fix to corner pass rebar(lower part rebar)

tension fixed lengthtension fixed length

lower part bar upper part bar

2) Balcony(Cantilever)

① The most important part in cantilever is the bar at the top above distribution bars.

It is common to anchor the top bars into a beam, however, they can be anchored in

a slab so long as there is no difference between their levels.

To obtain adequate fixed length is most important.

② Bars at the bottom should be anchored securely to provide for earthquake and

tornado.

③ When the level of cantilever and slab plate are different, bars in the slab should be

anchored onto the beam.

If the bars at the top are bent to be anchored onto the opposite slab, there might be

a crack due to tensile strength.

The bars at the top should be maintained with bar support.

tension fixation

tension fixation

vertical/horizontalD10-@220

upper support rebar

upper support rebar

spacer

spacer spacer

spacer

3) Parapet rebar arrangementThe expansion of topping concrete at the top of a building due to variations of

daylights will pass out great compression load to the parapet.

Therefore, the double reinforcement

in the parapets are better to be

anchored onto beams or slabs.

4) Reinforcement of slab open point

Explanation :1) In case the length of open part is

over 1,000mm , you should arrangeafter receipt of permission ofstructure supervisor if there are norebar arrangement detailed drawing.

2) *mark :arrange to single arrangementif established rebar arrangement issingle arrangement arrange to doublearrangement if established rebararrangement is double arrangement

3) ----- is established slab rebar4) Rebar to not specified of rebar size

must use same size rebar asestablished arrangement

Parapet might occur vertical crack mainlybecause the length is long. It is effective to avoid crack by arrangingto outside of horizontal rebar.

D13(reinforcement bar)

tension fixedlength

Use 90°standard hook rebar

In case open part is over 300mm,4 edges should reinforce 1-HD16

Reinforce each rebar to both open part asrebar distance 75mm for +1 unit of rebar Q’ty tobe cut existing rebar from open part.

min

imiz

eop

en p

art

L<1000min. 600 min. 1200

5) Details of reinforced rebar on concrete wall open point① Circle type open part

② Square type open part

Explanation :

1) In case the size of open part is D<150mm, omit vertical & horizontal rebar

2) mark : arrange to single arrangement if established rebar arrangement as

siugle(double arrangement as double)

circle type open part distance should be over “D”

max. 600 max. 600

In case of over D>450mm1-HD16×1800mm

1-HD16

min

. 600

(TY

P)

min. 600

open part

6) Rebar arrangement of slope way in main entrance

7) Trench rebar arrangement

90°standard hookD10→120

tension fixedlength

tension

fixed le

ngth

tension fixedlength

tension fixedlength

lamp slab rebararrangement

tension fixed

length

20. Steel frame(Deck plate S-ring)

In arranging the bars at the top, mount the deck plate and place the bars on the

furrows of deck plate firstly.

And then arrange the top bars above deck plate and connect these top bars with what

lied on the deck plate using hook to maintain the constant space between them.

※※ What is Deck plate S-ring ?

In order to connect working of lower part & upper part rebar in deck plate, the

arranged method shows on drawing.

As you can see as below, there are rebar arrangement operation by using rebar

D10 Deck plate S-ring.

However, if some construction site would like to reinforce D10 rebar by hand,

there are possibility to reinforce rebar roughly because its working is very hard

and with low efficiency.

If so, it is weak point of construction carry-out and high possibility of problem

after construction.

"S"-shaped ready-made hook manufactured by Taeyeon Machinery Co. Ltd. is

convenient to install and has efficiency to keep distance and keep cover.

21. Caution and consideration of construction carry-out

1) A man-dayThe amount of reinforcement that a skilled worker can place a day is, in case of slabs,

0.26acre ~ 0.33acre in area, about 500kg~700kg if converted in weight.

※ Daily work capacity(varies with working environment)

2) Weight of concrete① Specific weight of plain concrete(without reinforcement) is 2,300kg/1m3

② Specific weight of concrete with reinforcement in it is 2,400kg/1m3

③ Specific gravity of lightweight concrete with perlite or gas-foaming agent is only

0.6~1.2

3) Load and external forceIn construction, load and external force are critically important factors to be

considered.

Load is classified as fixed load and occupied load, where the former is the weight of

building itself and the later is the weight of people, furniture, equipment, etc..

Occupied load is classified again as long-term load and short-term load.

① The weight that 1m2 (square meter) sustains in long-term loading is

ⓐ Human or furniture 200kg/1m2

ⓑ Snow load 50kg/1m2

Classification

factory, school

apartment, house

<processing separately>

Q’ty(kg)

over 700

below 700

KR 130,000 per worker’s labor cost in 2006 year.

Classification

D10 stirrup, tie hoop

D13 stirrup

bending

<cutting separately>

Q’ty(kg)

600

800

5ton/1 person

② If weak at the long-term load : There might be a crack in walls or beams.

③ If weak at the short-term load : There might be not a crack but part breakage due

to external impact.

4) Crack and shrinkage① Crack of concrete is not simple problem to catch with several symptom such as

crack direction, etc but it is required to the inspection of professional.

Regularly, the crack under 0.3mm will be happened by dry shrinkage for

beginning vulcanization.

② Shrinkage of the building

If the length of the building is longer than 50,000mm, there is expansion or

shrinkage of the building, 10mm ~ 20mm, within temperature range from -18°C

~36°C.

(temperature difference×10-5×the length of building = difference length by

temperature gap(expansion or shrinkage))

③ In case of Korea, temperature difference is 54°C, from -18°C in winter to 36°C in

summer, According to the formula above, expansion in Korea is 27mm maximum

from 54°C×( ×50,000mm) = 27mm, hence there should be expansion

splice in some parts on high building & walls to prevent crack of the building.

5) Caution if construction work does① Distance of main bars against girder(beam)

ⓐ Beam plays an important part in a building, receiving the load from slabs and

passing it out to pillar.

Therefore the reinforcement in beams should be seriously taken into

consideration and accuracy.

Top bars, bottom bars, reinforcement bars, bent bars and middle bars are placed

in beams and distance of reinforcement should be more than 25mm or 1.25

times of the largest aggregate that is in the mixed concrete, over 1.5times

distance of rebar diameter.

ⓑ Splice length of top bar in beams should be required fixed length if it extends to

the center of column and therefore sustains tensile force.

Splice of the bottom bars in beams should be within from the end of beams,

where load is almost 0, and the top bars should avoid the end span of

beams.(min. rebar cost will be over 0.35%)

② Pillar

ⓐ Pillar also has important role to divide total weight and compression power of

building.

Distance of main bar also arrange bar fairly, distance per rebar and rebar will be

over 40mm or over 1.5times of rebar using.

ⓑ The minimum size of column is more than 200mm and cross sectional area

should be more than 600cm2

ⓒ Splice length applies B class splice length.

6) Reinforcement to prevent shrinkage of wallThe building might get shrinkage on building by the expansion of temperature in day

or the down of temperature in night.

Rebar concrete has expansion or shrinkage, and so there are possibility of unexpected

rebar.

Therefore, the point of crack possibility must reinforce outer wall without open part.

Arrangement direction of correct reinforced bar, it can be checked crack correctly, it is

principle to arrange bars vertically against crack direction.

If there are crack on both edges of wall by the expansion of roof, reinforced bar is

principle to arrange bars vertically against crack direction and you reinforce the

reinforced bar of highest wall to outer top pillar & retaining wall of building.

The expansion ratio of roof will be bigger toward outside and very small roof on

center of building.

Also, 1st floor contacts ground do not effected of the influence of temperature.

Therefore , the part of highest influence by expansion & shrinkage of roof is outside

wall and there are expecting many cracks.

Without marking on shop drawing, you must arrange construction with your sincerity

with our experiences.

7) CleaningIt is better to install concrete after cleaning always before installing concrete.

When you checking construction site, there are many other materials to decline the

quality of concrete such as soil, sawdust, trash.

You must delete it inevitably.

After concrete job, you must break concrete of ground and brush concrete on rebar

with hammer drill, wire brush , hammer on next floor splice part, wall, pillar.

8) Problem if oxy-acetylene cutting does

① Don't use the oxygen arc cutter near the pile of unused bars.

If you use the oxygen arc cutter near the piled bars, high heat from cutting rod will

be transferred to unused bars causing thermal deformation or unexpected failure.

Automated cutting machine and bending machine are recommended.

② Oxygen arc cutter will drop tensile strength of the bar, which is critically important

to the reinforcement of the structure, and there might be problems in structural

safety.

③ Manual bar cutters have been normally used in the construction sites so far.

However, in order to increase the effectiveness and ensure perfectness, automated

cutting machines and bending machines are highly recommended.

<Reference>

Rebar arrangement should arranged by the shop drawing.

Technicians must increase the ability to see shop drawing if it is the recent drawing by

limit strength plan method.

22. Gas pressure welding of Rebar

1) Definition of gas pressure weldingIt is welding method directly of raw material itself to press under the condition which is

before heat melting(1,200°C~1,300°C) for junction part with oxy-acetylene gas to fix on

both side rebars to connect in carrying out of rebar concrete structure building. Also, it is

economic splice method than folded tying (lap splice), mechanical spiral tying(mechanical

splice) and also the strength of junction part is stronger than raw material.

※ Rebar splice is classified to folded tying (lap splice) , mechanical spiral tying(mechanical

splice), compressed tying(welded splice). Folded tying (lap splice) is commonly have used as

important method for rebars of small diameter before. However, Folded tying (lap splice) has

irrationality such as complexity of rebar arrangement and bigger material section and also the

increase of mold cost and so it is prohibited to folded tying (lap splice) for over D29 deformed

rebar on Korean concrete standard specification and mechanical spiral tying(mechanical splice),

compressed tying(welded splice) will be applied frequently. Therefore, compressed

tying(welded splice) is stronger and economical splice method than Folded tying (lap splice) if

rebar arrangement with density or rebar diameter is bigger and it is using for the rebar over D29.

2) Composition of automatic pressure welding equipment

<Welding units>① Oxygen pressure controller

② Acetylene pressure controller

③ Acetylene outlet hose

④ Oxygen outlet hose

⑤ Welding torch

⑥ Welding tip(4 edges)

<Compressor units>① Pump

② Pedal pump

③ Hydraulic pressure hose

④ RAM cylinder

⑤ External cylinder

⑥ Fixed clamp

⑦ Flexible clamp

⑧ Rebar

3) Working sequence to tie gas pressure welding The method of gas compressed tying(welded splice) is classified to manual gas

compression and automatic gas compression method and the principle is same but

difference is by manual or automatically for splicing.

① Grinding the section of rebar with flat by using grinder

② Install rebar for splicing to pressure welding equipment

③ Heat and pressure

- Heat rebar with gas mixed oxygen acetylene

- Heat machine will be used multi-hole burner

- Heat and pressure at the same time

- Don't heat till the temperature of rebar melting but heating to 1,300°C as rebar

exterior temperature (it is different from welding splice)

- Pressure to 300~400kg/cm2 per rebar 1cm

- Use hydraulic regularly for pressure machine

- It shows time-passage of standard heat, pressure power as above graph.

- If starting heat, pressure from A point, the section space will be decreased on B

point and finally adhere completely to D point.

- It makes inflation by increasing pressure between F-G to keep this temperature

< Time passage of heat, pressure power >

1st heat pressure

pressurepower

pressurepower

temperature temperature

time(second)

2nd heat pressure 3rd heat pressure

4) Required time to heat for pressure welding per diameter

5) Inspection of gas pressure weldingInstruction of welded part includes visual inspection, ultrasonic detecting test and

tensile test, etc.

Selection of inspection test should be determined in accordance with suggestions on

the drawings.

① Visual inspection

welding distortion, deflection, shape and dimension and any other defect can be

inspected with eyes.

② Tensile test

- In case of manual welding equipment, tensile test is conducted for sampled

specimen

- In case of automated welding machine, test piece is manufactured for tensile test

③ Ultrasonic detecting test

In inspection of welded part, visual inspection and destructive or nondestructive

test are run parallel in general.

Among these, destructive test not only takes times and costs but also had some

errors because only a few test pieces are sampled from the entire welding spliced

bars.

As a solution, reliable nondestructive test is conducted to find out defects from all

welded parts

Required heat time

40 ~ 50sec

50 ~ 60sec

60 ~ 1min 20sec

Rebar diameter

HD16

HD19

HD22

Required heat time

1min 15sec ~ 1min 45sec

1min 45sec ~ 2min 15sec

2min 15sec ~ 2min 55sec

Rebar diameter

HD25

HD29

HD32

6) Caution if pressure welding works

① The builder will get the admission of person in charge to select gas pressure

welding worker.

② You must check and maintenance inevitably before working for oxygen , acetylene

instrument and protect it from direct rays.

③ The compression section should be decreased by cutting of plane after deleting oil,

paint, cement piece, etc but to be cut the neighbor surface by grinder.

④ The final pressure of rebar discharge direction should be over 300kgf/cm2 per

dimension.

The diameter of compression protrusion part should be over 1.4times of rebar

diameter and diameter of compression protrusion part should over 1.2times and

the form should be smooth.

But , it is followed by in case it is fixed by shop drawing separately.

23. Mechanical tying of Rebar

1) What is mechanical tying of rebar?It is essential construction method for large scale civil engineering construction such

as high-building, bridge, dam, etc and underground building anti-earthquake plan and

also special construction. It is a splice method for strong economic quality assurance if

folded tying method is impossible in case rebar arrangement with density and rebar

diameter is bigger and so by the increase of rebar strength & concrete strength. It is

applicable for deformed rebar to use rebar concrete building. In foreign countries, it

was verified from 1960 and it is using for Korean construction site from mid-1990.

2) Type of mechanical tying of rebar

3) Screw-type tying of rebarrebar warehouse-in → make rebar screw process drawing → start processing of screw type

→ deliver to construction site(3~10days from order date)

screw type

inflationtype

compressiontype

joint ribcut type

tapertype

others

mortarinjection type

gascompression

hydrauliccompression type

site tie type

joint fixed bodyadhesion type

joint rib compressedjack adhesion type

processtype

process type inflation type compression type joint rib cut type taper type

inflate of rebar processingpart largely by mold(example) rebar 25mm - M30case screw type

bury rebar joint rib bymold (example) rebar25mm - M25.5

processing screw after deletingrebar joint rib with fixed size(example) rebar 25mm - M26

screw processing withangle of rebar front end

prove the confidenceafter processing of lowcarbon steel bar(SD300)available for largeproduction

prove the confidence afterprocessing of low-midcarbon steel bar(SD300,400)available for largeproductionavailable for production onconstruction site

prove the confidence afterprocessing of low-mid-high carbon steelbar(SD300,400,500)available for large productionavailable for production onconstruction site

prove the confidenceafter processing of lowcarbon steel bar(SD300)available for productionon construction site

the inflation processing endmight has low confidence ifit is caused by processingvulcanization of mold incase high carbon steel barlow confidence afterbinding 2 rebarslow confidence in case ofbending

the compressionprocessing end might haslow confidence if it iscaused by processingvulcanization of mold incase high carbon steel barlow confidence in case ofbending

coupler size is 10%longer than inflation &compression type by thedeviation of size ofrebar joint & rib

low confidence ofomission & untying fortesting tension strengthand repeat test

case screw type case screw type cut screw typescrew processing

merit

demerit

4) Site connection-type tying of rebaroutbreak of splice → carry-in of parts(arrival to site within 12hours after ordering) →assembly & construction carry-out → inspection comparing other splice part

process type

classification joint fixed body adhesion type joint rib compressed jack adhesion typeprecision processing & molding per part of splicepart base on joint groove of rebar(no artificialprocessing of rebar)

precision processing & molding per part of splicepart base on nominal diameter of rebar(no artificialprocessing of rebar)

available to assemble without processing screw onrebar

available to assemble without processing screw onrebarease to bind regardless of rebar type(foreign &domestic rebar , deformed rebar , comb-patternrebar , X type)available for large production per rebar title

need pre-education for building assembleravailable for deformed rebar only in Korea and lowconfidence of binding in case disorder of toleranceof rebar joint rib and trademarkneed pre-education for building assembler

merit

demerit

inflation screw swage screw joint-rib screw taper screw

cut processing cut processing cut processing cut processing

pre-cut after mold inflation mold compression pre-cut processing angle processing

case screw case screw case screw cut screw

lock nut fixed pincompression jack

lock coupler

connection jack

fixed bodyrebar

length after bindingoute

r dia

met

er o

f cou

pler

double facedcoupler

5) Other tying of rebar

process type

classification mortar injection type gas compression type hydraulic compression type

splice part to perform platform onrebar joint & rib groove & insideof connection part

heat & compression splicemethod of both ends of rebar byusing oxygen & acetylene

splice method to adhere sleeve bypressing outside sleeve afterclosing rebar to soft sleeve

using to pre-cast(PC) spliceconstruction method

using in Japan mostly and provethe confidence of tensioncompression

using in europe partly

splice part is large and longexcessively and low confidenceper rebar typedifficulty of confidence proofof construction site carry-outproduct

big tolerance of constructionsite carry-out per condition oftemperaturedifficulty of confidence proofof construction site carry-outproducttroublesome of purchaseseparately of compressed rebarfor compression reinforcementto classify to producecompression bar & regular bar

difficulty of reinforcementbecause the possibility ofdisplacement of pressurestrength for 1pc & 100pcs andalso the movement of pressuretool

merit

demerit