Designed and detailed (BS 8110: 1997) J. B. Higgins and B. R. Rogers MA. CFng, MI(I

Contents Foreword 2 Introduction This third edition of Designed and detailed has been revised to BS 8110 : Part I:

1997, and the amendment dated 15 September 1998. Although there have been 3 BS 8110 and limit state design several amendments to the code since 1985, the latest and most significant change

has been the reduction in the partial safety factor for reinforcement m from 1.15 6 Design information . . to 1 .05. With higher stresses, less steel is required. However, the total saving may 7 Structural summary sheet not be fully realised because there are other considerations such as choosing a

practical arrangement of bars, and the deflection in the case of shallower 8 Floor slab members.

10 First-floor main beam The calculations have also been revised for the loading requirements of BS 6399 Part 1: 1996 and Part 2: 1995.

16 Edge beam . Design charts in BS 8110 : Part 3: 1985 may still be used to provide a 18 Columns conservative solution, and one of these charts has been included for the design of

columns. Lap lengths for these members have also been taken from BS 8110, 22 Foundation Table 3.27, but adjusted for the design stress of 087f. 24 Shear wall The tie reinforcement for robustness is designed at its characteristic strength. If the

characteristic bond stress is used for calculating laps and anchorage lengths, then 26 Staircase the values in Table 3.27 may be multiplied by I 05/l4. This publication takes a

conservative practical approach and uses directly the values given in Table 3.27. 28 Column design chart Observant users of previous editions will appreciate the skill that is evident in the

29 Further information setting out of the calculations and the drawings. This is the work of the late Jim Higgins, whose care in the production of the original artwork was meticulous. Sadly, he never saw the second edition in print. I hope that my amendments to this third edition will not detract from his fine workmanship.

Special thanks are due to Tony Threlfall for his advice and suggestions for this edition.

Railton Rogers

Introduction

The purpose of this publication is to apply the principles of limit stale design given in BS 8110 by means of a simple worked example for a reinforced concrete building frame. The calculations and details arc presented in a form suitable for design office purposes and are generally in accordance with the following pLihI ications.

BRITISH STANDARDS INSTITtJTION Siructural use 0/concrete. Part I . Code of practice/or design and construction. Milton Keynes, BSI. 1997. 120 pp. BS 8110 Part I: 1997. H M STATIONERY OFFICE. Building and buildings. The Building Regnlation.v 1991 (Amended 1994). HMSO, London. 21 pp. Statutory Instruments No. 2768. BRITISH STANDARDS INSTITUTION Loading/or buildings. Part I . Code 0/practice br dead and inposed loads. Milton Keynes. BSI. 1996. It) pp. BS 6399 : Part I 1996.

BRITISH STANDARDS INSTITUTION. Loading/or buildings. Part 2. Code 0/practice Jiir wind loads. Milton Keynes, BSI. 1995. 82 pP BS 6399 : Part 2: 1995. BRITISH STANDARDS INSTITUTION. Loading /ir buildings. Part 3. (ode 0/practice /r imposed roo/ loads. Milton Keynes. BSI. 1988. 23 pp. BS 6399 : Part 3: 1988. BRITISH STANDARDS INSTlThTIO'J. Specification /or scheduling, dimensioning, bendin' (111(1 cutiin' steel rein/irceinent/r concrete. Milton Keynes, BSI. 1989. 20 PP BS 4466 : 1989. IIIE C( )NCR VIE SOCIETY. Model procedure /ir the presentation 0/ calculation,r. London (now Slough). 1981 . Technical Report 5, second edition. 18 pp. THE CONCRETE SOCIETY AND THE INSTITUTION OF STRUCTURAL F.NGINEERS, 5iandard method o/detailnig structural concrete. London. The Institution. 1989. 138 pp.

BS 8110 and limit state design

c:)bjective To serve its purpose, a structure must be safe against collapse and be serviceable in use. Calculations alone do not produce safe, serviceable and durable structures. Equally important are the suitability of the materials, quality control and supervision of the workmanship. Limit state design admits that a structure may become unsatisfactory through a number of ways which all have to be considered independently against defined limits of satisfactory behaviour. It admits that there is an inherent variability in loads, materials and methods of design and construction which makes it impossible to achieve complete safety against any possible shortcoming. By providing sufficient margins of safety, the aim of limit state design is to provide an acceptable probability that the structure will perform satisfactorily during its intended life. Limit states can he classified into two main groups: (I) the ultimate limit state, which is concerned with the provision of

adequate safety; (2) the serviceability limit states, which are essentially concerned with

durability. Generally, in practice, there are three limit states which are normally considered for reinforced concrete and these are given in the Table below.

Serviceability limit states Ultimate limit state Deflection Cracking

Objective Provision of adequate safety

Structure should not deflect so as to impair use of structure

Cracking should not be such as to damage finishes or otherwise .

impair usage

Loading regime Design ultimate loads Design service load

Performance limit Structure should not fail

Deflection should not exceed specified limits

Crack width should not exceed 03 mm generally

Characteristic values For the testing of materials, a statistical approach can be applied to the variations within materials which occur in practice. A normal or Gaussian distribution curve is assumed to represent the results of the tests and a value known as the characteristic value can be chosen below which not more than 5% of the test results may be expected to lie. The characteristic strength is given by the equation: Characteristic strength = Mean or Average strength L64 X Standard deviation Ideally, a characteristic load should be similarly defined, as a load with a 5% probability of being exceeded during the lifetime of the structure. Flowever, it is not yet possible to-express loading in statistical terms, so the Code uses the loads defined in BS 6399: Parts 1, 2 and 3.

3

Desiqn toads The design load is given by the equation: Design load = Characteristic load X

where 'r is a partial safety factor for loading. This factor takes into account the possibility that the loads acting on the structure may be greater than the characteristic values. It also takes into account the assumptions made in the method of analysis, and the seriousness of failure to meet the design criteria for a particular limit state. The consequence of collapse is much more serious than exceeding the serviceability limits and so this is reflected in the higher values of the partial safety factors. Components of load have to he considered in their most unfavourable combinations, Sc) sets of values of for minimum and maximum design loads are required. For example, the worst situation for a structure being checked for overturning under the action of wind load will he where the maximum wind load is combined with the minimum vertical dead load. Lower values of ;' are used for the combination of wind, imposed and dead loads than for the combinations of wind and dead, and dead and imposed loads, as the probability Df three independent design loads achieving their maximum value at the same time is less. The table below gives the partial load factors for the ultimate limit state.

Combination of loads

Partial safety factor to be applied to dead load imposed load

wind when effect of load is load

adverse beneficial adverse heneficEal

1 Dead and imposed 2 Dead and wind 3 Dead and wind

with imposed

14 14 12

10 10 12

16

12

1)

12

14 12

Deiin strenqths The design strength is given by the equation: Characteristic strength [)esign strength = ______________________

where is a partial safety factor on the material strength. This factor takes into account the variation in workmanship and quality control that may normally be expected to occur in the manufacture of the materials. The values of to he used for the two materials when designing for the ultimate limit state are given below:

Values of , for the ultimate limit state Reinforcement I .05 (oncrete Flexure or axial load IS Shear strength without shear reinforcement 125 Bond strength 14 Others (e.g. bearing stress) 15

iOLisiuest In addition to providing a structure that is capable of carrying the design loads, the layout should be such that damage to small areas of a structure or failure of single elements will not lead to a major collapse. The Code requires that in all buildings the structural members should be linked together in the following manner: (a) by effectively continuous peripheral ties at each floor and roof level:

4

(b) by internal ties in two directions approximately at right-angles, effectively continuous throughout their length and anchored to the peripheral ties at each end (unless continuing as horizontal ties to columns or walls);

(c) by external column and wall ties anchored or tied horizontally into the structure at each floor and roof level;

(d) by continuous vertical ties from foundation to the roof level in all columns and walls carriing vertical loads.

In the design of the ties, the reinforcement may be assumed to be acting at its characteristic strength with no other forces present but the tie forces. Reinforcement provided for other purposes can often be used to form part or the whole of these ties, so that in the design process, when the required reinforcement for the usual dead, imposed and wind loading has been found, a check can be made to see whether modifications or additions to the reinforcement are required to fulfil the tie requirements.

Durabflty and re resislance At the commencement of the design, the following should be considered: the climate and environmental conditions to which the concrete will be

exposed; the concrete quality; the cover to the reinforcement. It should also be noted that the quality of the construction process and the Iirst hours after casting of the concrete have a major influence upon the subsequent durability of the structure. The cover for protection against corrosion may not be sufficient for fire protection, so this should be considered at the onset of the design, and also the dimensions of the members. The Code gives maximum water/cement ratios, minimum cement contents and minimum characteristic strengths for concretes suitable for use in various environments with specified covers and using 20 mm nominal maximum size aggregate. The minimum grades will generally ensure that the limits on free water/cement ratio and cement content will be met without further checking.

Appflcation Durability and fire resistance requirements are considered at the onset of the design process because this determines the grade of concrete, the cover, and the size of the members. Usually, for most structures, Part 1 of the Code will be used in which it is assumed that the ultimate limit state will be the most critical limit state. Design will therefore be carried out at this limit state, followed by checks to ensure that the serviceability limit states of deflection and cracking are not reached. In special circumstances, other limit states, such as vibration or the effects of fatigue, may require consideration. Should it be necessary to calculate deflections and crack widths, methods are given in Part 2 of the Code. The serviceability limit state of deflection may be the limiting requirement for floor slabs with large span/effective-depth ratios. This can he checked before the reinforcement is determined, although some engineers may prefer to follow the procedure where the check is made after the reinforcement has been found. Simplified detailing requirements for the curtailment of the reinforcement may be used for beams and slabs which fulfil certain design conditions. Nowever, for other situations, the curtailments should be taken from a bending moment envelope and be in accordance with the general recommendations of the Code.

5

Design information

Client W Co#.ai Architect Engineer responsible BRJZers /j, Building Regulation authority or other and Date of submission

TLe. LIL14 'a, 5SiO T tnj L of Cocre.tc Past 'j. S7 Pout P 2 IO5)ckr PCU B8 Relevant Building Regulations and Design Codes

Lbon Intended use of structure Fire resistance reqLnrements

Roof 5 -

F1'oo irvoecj C) &ct tL3r 4.QkW/ Sjr- 4O k4/ Fors a LXc Co4

General loading conditions

Speed 2 a/ec (basic Factors 105 Sb = 171, S 1.0 S = 1 O S Co'84, C +O(*r.') ,., O3((),C_r=QO2S

Wind loading ccnditrons

e.'Jere. 4 (Vd ('ixaS) (S6llOTcie3.2) Exposure conditions - v\O

AoLjo, beac rreure 2oo Subsoil conditions

R1c fs o k4 ov wcik Foundation type ,r-A4e. 4o wt '20. , a (IIOTcIb3.) Material data

L. strek - fL 4o - 1iJ'c '

Sdf wet 4'ok4/ AU S-oir,. ov ore

Other relevant information

Structural summary sheet

3 1'2..4.2

t, AU CoCa z, Mbean , bW4w

-l wall

W1 t5-rAI4cE. i, IiP w orce r4 eA

e4A kax- vodk. . Lr brG L EW kor

prviAed. b ctrc or. r4 /ui, o4 r4 /"44 -3

C C

Ft C2o4\0) = 2Q+lG 3G(Ok,

P - Perpcc ;te It. ter e a - w wc

7

G 5ooO=4oooO

0

0-I 175

11 fl5

S S S 0

T"{P1CALLOOR PLA4

oox3oO OOx'oO SO OO

3

T'-(PICAL cRoSS- C'TtoJ. SJe: ICryo,, CoS,$.275Ox'l75OxOO

C C- cPc

P ><

Ir. rEt, w

C C C cc C C Tia PRVSi -

Floor slab interior-span solid slab

175

5000

BS 8110 ref. CALCULATIONS OUTPUT

3.?, T c3 3 34

DugPB%t.vr' ct FR.E REITA4C W.L4S4 ov hr U4 CovCt.ov of ik cover .. '2o si.

3.r.2,4 Tb(3,12

LoA O.17E x 24 4.2

F (G4t ) 0. r toc.d = 4.7kt{/

Cpa.ge c) = 4. okN/ Dgvtoati t.1r47+ 1.x4) 50

3k 4.7kN/2 401 F

32.4 Iable3i2

ULXIMATE /Vs Iraror r.spo. o.oC,3F =0.OCx,43x5O = 2O.4kh/ wct 4.DrtS

4.44

Tb(e8

FCEfrT k 2o.4 0 0Th 4o-1ox4S2 t4 ppor.

oc'23 = i4s(o.S+J(o.Z ) = i (buto.x1494s:

A5- PA 204x1& - O.95 O.9546Ox14l5 - Cdr5cear o.S4.91O3' 0.22 M/w lc?x 14S

=

Top&otow T12. 0o (iiJ) ok.

TQ6k Tok3IO

DLaC.T(oi.4 6k /4faeq rio = PA 2o4d0',. 031 2x4(O33O I4')

- 3 x 317 cr or WOr re.L.'.ft. 1 5 . Atlte '21.5

'I 5000

- 33 $(o 149 , r4o oc. 2U.27 CR.Acl(ii 447

p-cj bt.twee. bo.r OC 12 34 k 11 , ( 2 oO ., rttQ. cJck.4 . c.*j ak.. k. 3.12.3.4

TAbteZ7

r PV(op..J o..ct4We5 ITR..iALii Ft = 3kN/.wd Torce 4t( 7 ( 4t)_ 4r.Lw>Ft

4S.x lo 44,0 -'fl' :#3oo. T12.e3oo (377

I

tso.l. 5T10.-41 2)00

i1loo 4

T "

'

-

C3*'Z)

5T10-41r2 It, I

S-rto--3GO'r2 I

L I (2+3) I

.J

Commentary on bar arrangement BS 8110 ref Bar marks Notes

All bars are labelled in the form described in the Standard method of detailing structural concrete, e.g. 45T12-l-300B1 means that in the bottom outer layer there are45 Grade 460 Fype 2 deformed 12 mm nominal size bars at 300 mm centres and the bar mark is -I-. The bars are numbered in the likely sequence ot fixing; the positions of the first and last bars in a string are indicated in plan and section. Intermediate bars have been omitted for clarity.

Table 3.25 Minimum area of tension reinforcement = 00013 X 1000 >< 175 = 228 mm2/m. 3.12.11.2.7 Maximum clear spacing of tension bars = lesser of 750 mm or 3d, i.e. 3d = 3 )< 149 = 447 mm.

h < 200, therefore no further check on spacing 1 Main tension bars Tl2 @ 300, A = 377 mm2 > minimum 228 mm2/m. OK.

If curtailed, A = 377/2 = 189 mm2 < minimum 228 mm2/m not OK. 3.12.3.4 Bars lapped 300 mm at bottom support to provide continuous tie. Table 3.25 2,3 Secondary bars use T10 @ 300 (262 mm2/m). 3.12.8.11 4,5 Minimum lap = 300mm > IS )< 10 = 150 mm. Lapping reduces bar lengths for easier handling on site.

7 Laps are shown staggered for effective crack control. 3.4.1.5 6 Minimum transverse reinforcement is placed across the full flange width of the edge beam (minimum

width = 650 mm, see page 16). Table 3.25 Minimum area = 00015 )< 1000 >< 175 = 263 mm2/m use TlO @ 300 (262 mm2/m).

8 Main tension bars over support 112 @ 300 as bar mark I. 3.12.10.3 One curtailment shown at 03 effective span from face of support. Further curtailments prevented by

minimum area and spacing requirements similar to mark I.

9

i,TIOc30OTQt

Al 1.

)

5Tt0-5JT' Mt.

B I

II U-

'2 .1 L

ST tO -51

1oo 1

30O

I L%o

'1

3

8T1O-2.00 '7T1O-3)2 Mt.

4

1

2

1

@_Th F

i_ (2) _i T10- 1300 7 TI 0- 'z) e2 AlL

4T'2-1- 300 P LA.1 (r4 '2 ovfte4 r c[ti)

A It AR. = alecY4J &r5

.45s Att

A-A

,z tt. - CovE.R toote 5= 20 $cale; i;o-

First-floor main beam two-span flanged beam

BS 8110 ref. CALCULATIONS OUTPJT

.2.I.21 Su.FR.P1ME. AL'-t'5 A taa.r ett. Ljs e.LLa.r ro4kcgd e' b er rMrv S C tD forces. F-or t -1oo be co(s.bosje &iiiwecL to be xed. 4 tse be(oi c 1ve. Ti. t'i.ov,. w ot prove rot rcd rert. Lart* 1L4 to a-re. takcr b sc-ur wcAk.

3 To.bk6

3,34

D ' F Ri STA CG COVW for vt co t.ov of eposurc 2o. ov1 cove ?OO wbefor -

cover t Ii4K5 20

.2122 LAPD4G p4 toc o75o.b CPe&) 5c4.7 2.S se-ieLt (o.o.r7s)o.3 x 24 = '23 oGa.w 2B.kW/, (.B) = x4 2o.Ok4/, Mv ce o4 i4 +

'(2 + 32 'i& k/s

103K 2S&k4/. Oc 2OOk/t. t.4

.i2k/M +t ) Bi Moie.m () .O ve4tl.Q% uie.4:

BA 1' cZUIL4 rowv AvJ I 12 ------ Ctk I 1oo4 wp

LtperCowC. Lower II Scur (k)

CASEJ1 CM IS%t Lij*- Cokiv v# ower sc-0- (1)

CDiLAI stf, Ler se (-!)

- 17$ 2O + 4o2 - 348k + Qc + ba + ii - 24 oo 22

(8't'2 -19 2.7( 4- 4$ 2So 28 - 4 4-it 7 + 'a-

34 #1's 2$2 i'2o 3

iii -

.54 e4 + 2o4 - 1- 33 + 2'

+ 17 - 52 - 4

1% 1 0 10

f =460 ............. tto

8000 6000 300

CALCULATIONS

MDN-E'JT ..NvLOPE

Rrnto V

FogcE E1LOPE

40 r CASE I 17S o .5S (SQ..e ii') 402 2&L (

O') II 1 (2o'J') II 34 S2 (I)

III o

{1 eatA.

wecoc 32S L

-UI

La6t I trbut&i

2? I 22 I

EveLop.

3511

oao

00 m.

1 I 2BBR I 3001 L

= 282

i55 k1 0.4

0.s 46o vw1

=

0

&s 2

0

s'. t&or (. .3 a 4T25

1 . . I,

440 J__ Lj4co

2 T 2B

Co

:vta.-vt Supor:

BS 8110 ref. CALCULATIONS OUTPUT

Fcor. ?JL Q1 = 0.7

K' O.4o2(0.7O.4')_01(O.7_Q.4)2 K Ot21 > O1o4 bd2

= 4oxooi4.4

42O 0.02'3

Mu 3EAM., t.FLOof E') 322t /ct 3.4.4.4 = o.io4

efoe 50 O > O7 /O.4,):. /c i-04 os ______ - so 04S A5 32.

< 10 t756 - 0.5x4Ox0.9Sx4SO

FroM .M.evop11) 2.2.1 = i5x tO

40 x OOx 45O (O.So. ') D2 :.- cl .4) As i,xtO O'Sx4,0.x 0.9rLx 450 ckovcbox: 775 o'S.c.4Ox4S1 75 x to

312'32'2 ..IC.b4rcksr= 190x S0/5) 2 x 4o,( '25 M

Frv .Vf. Cvveloe M

=

.M.evei.oe, 3.4.j. E. . .OO+ 0.14 x (,00O M = OO7, cu

A 13x 10

4 T 2 E (tO tc...o ".

= O.O,4

657 MAM

So -

2T25

__

j nPoo )25,, a.6

1t40

12

4o 4So Ce4c Abt9e4

we.b o.oo K300X 500 = -se. or-.oVe.r Spport,0.002fx3Q0oO=

TLc 2 T 2S (8lr.

t&4%SLO

BS 8110 ref CALCULATIONS OUTPUT

34.G

T.6te3'B

TIe7 2 45.5 Tbe37

Tobe7

SkEAR REll4PORcMEJT Ccve. tior, re.L,, 2T2 (82 w2)

4ooA - 100x2 073, \!c 0S7(- b OO4SO / t'vvk A 6 0.4 OOx 04 OSS(2O ' = 075 ' 4B0 00TrR2oo

.(vO7O4.o59/2 Sv 3oo 0'

d.4SO

Skct R12 Lk oo io 2 A/ o.7s j 2 J .50 j 1t T6137 4StO Loao 8LM V.f.d 2t V/N/ j(oo vv 0% Ay tlS Lks R'l2C. 175

R. 2 3- i 12 R 1 300 R..t'2. @ 3oo

,,

L.H 25 2M

'32 jsc O.o

tSS j.14

R.L V1G875 k..N

.o3 2S

37 O.'9

p.51 O.7

34..1 T.bIe9 3.4, bkto

FLECTION1 b-Lo= M 2x 4(oOic I75i27 23/2 b 42Ox4SO2 3x 1%O 325

ctor i..5 224 Acto - &000 - 450 . ,

'2.t1.2.

Tk32g 3ViII2 3 I2124 2i2

C AC t rk ba pa 1

:c-.k ct; J

1V\ T'VLOY. \'L4. I 0/ f & xtr-.f sport T 2o

+ 18 I.e.raS $..4por-t T 30

0 e,

153k Nn Extntot QIon4 T.C.P(3.1,S a. cL450.

2) b = 300. (. C t.Lo. ct. 5 =

/IT.C.P to pt, we4- M 2 Commentary on bar arrangement US 8110 ref Bar marks Noics

lius beam shows loose splice bars at each column intersection. Ihis met hod simplifies detailine and 0 sing and the span cage can readily he prefabricated.

I Tension bars arc stopped 50 mm from each column lace to avoid clashing with the column bars 3.3.1.2 shown in section A--A. Nominal cover 20 + 12 32 mm > 25 mm, say 35 mm. 3.12.9.1 2 Remaining tension bars stopped off as shown in the curtailment diagram above. 3.12.8.14 ('heck masimum amount of reinforcement at laps < 40 breadth

4 >< 25 = 100 mm < 0-4 X 300 = 12)) mm OK. 3 loose bars arc fixed inside column bars as shown in section BB. Although designed as compression 3.12.3.4 bars, these bars also act as internal ties and lap 1000 mm with the adjacent span bars for continuity.

4 The two tensioil bars are stopped 51) mni from the column Oice to avoid the column bars beyond. 5,10 loose Ibars are bxcd insidc the column bars and provide continuitS for column and internal ties.

3.12.11.1 ('heck minimum distance between tension bars 25 mm (aggregate si/c f 5 mm). 30)) 200 - 100 mm ' 25 mm OK.

3.12.9.1 Top legs propect from centre-line into span. minimum dimensions shown in the curtailment diagram. '4

c,2R12 - 11

5

i4eoO

A 'ZTi6- G

t '12 t

2

4 A-A

___

-

: O

'2T2,-2

ELE VAI 1 For o ba.c 4 r .stcxxce M o 2T2S ('3&2

= c1_ xO.95[j] M= O.5fx4x, (3.4.4.4.) a bdxO a= Top: b=300, /4o.9i2)MJ7 Bt,n: b 1420> = 0., M13'5km. 4LY Mo Ev.ve1opii.

& ____ 1o l_o.I_ _____ 1s

CURTA1LMT DIAGRAM.

'75 bOO

M A1P4 EAM

cer

LNK DARAIY\

3.12.3.6

3.12.8.14 3.12.8.3

10

3.12.8.3 6.9

3.12.9.1

3.12.4.1

7.8

Bottom lcts lap minimum 00)) mm with span bars to provide continuity for the internal tie. 'lop legs 5 + 450 1315 mm ) let both legs Bottom lees 200 100)) 1200 mm ) project 350 mm. say. Note that the bottom lees are raised to avoid the 40i rule in the lower layer. ('heck hearing stress inside bends. Jy ' 55 br each radius to simplify bending. 'lop legs 535 - 450 05 mm ) let both legs Bottom legs 20(1 4- 1001) 1200 mm ) project 1200 mm. say. Else r 4d minimum radnis bends. link hanger bars arc same length as bar marks I and 4. Bar is one size larger than links (n' inimum 12 mm). 'Ihe tension bars over the support stop as shown in the curtailment diagram. These hai's arc Oxed inside the column reinforcement as shown in section BB. 'Ihese bars are bundled vertically in pairs to reduce congestion and this also allows a gap(ninimuni 75 mm) for insert mii of a vibrator.

II ('hosed links, shape code hi. are arranged to suit the link diagram above. Open top links, shape code 77. arc not suitable for the sites shown.

3.12.8.12 Note that links it laps are spiLed at ilot greater than 200 mm since cover I'S bar size. 15

Edge beam interior-span flanged beam 1=

t f '350 5000 300

BS 8110 ref. CALCULATIONS OUTPUT

To.bIe 33,34

DL,RAILITY FIRE. 'S1iCE NDw2aJ Cver tjqr Ovc cf ex?oure = 4OA..

3OOwde. be.4 for ir.ero /vLLMtA Co/e.r 4O%W%

LoAi Ie44 CooA 4!rov 2x2 294

6-3 25.0 o-7kL .'

ose4 i osab(p.t W'25 2.sokM. byi (o.4 544o 125.0kg. k= QO.7kJ k= 2Ok. F =i'zsok.

TAb(e..35 ULTtMATE .M'S IrorsorC M.oo8F OO&xt?x5 O.OkW Wtt4. a: M E O.07 12Sx 4S

444

3.415

Ta'5 4;,Io

Tcbk7

5Qx0' OO5 t.rLor os: bd2 4ox oox'2So (o.s+a;- 0'O) A: 0Xi0 442. o5,46OxO'S7x2&D

M4-Ltcuy; e.fewi4t = - 43.9x Cu 40X650x 2902 002., A

SrorceO5SF*12S6875kN, fc'ot reforea.rc2T20 'Larforce G8'75_ (D. I+ 0.28) 2S

1oo4 o.is 5BxD = 0.G3N) bd 3oo,'2PO / 3oox2.BO v o3) M - 43.SIo' 2 x 4o 2 5ox29O - 3x 4o2 272N/rn . Moft.a,. fi*4or 153 ,1Aow*bLe. s&r/cff.dLp rto = 22 x

1 ooo 17.2 2O .'. k.

l2cI.2A Tcbe ) 3.12 (.2.4

CAc OFO rs 27/ (sedeco) 7o \9>1s CC A(oJb d&rcpczc 2g T0p 2 ar5o chkC

= 41000 220 ,coc rdtsre O0 QvJLQ CtE'oe 5.Cj'% 2L

,1 I

ok oiIc27 3..U TIE. PR.oVl,O4 -eLF4. A5j . U'L'Tt2, 4t= . x74 45 3oc To - 'ZTVZ.

Bar marks Notes Horizontal bars in this member provide the peripheral tie. Minimum lap = 300 mm. I The two tension bars are stopped 50 mm from the column lace to avoid clashing with the column bars shown in section A-A. Separate splice hars are fixed inside vertical column bars. Minimum area = 30% A = 03 x 364 = 109 rnm. Use 2'T 12 = 226 mrn. I ap = 35 >< 12 >< 109/226 = 203 mm > 15 x 12 = 180 mm < 300 nim. Use 300 mm lap.

3 Link hanger bars also provide support for slab top reinorcenienI. Minimum area = 20% A sI1pT1 = 02 x 436 = 87 mm. Use 2T 12 = 226 mm.

4 Tension reinforcement over support is fixed inside vertical column bars. Bars are curtailed at 025 span from lace of support = 025 x 5000 1250 mm > 45 x 21) = 900 mm

5 Closed links are shape code 61

'23R405-200 A1

je- co

2 T '2O 4 n

A EL EV Ar iot

-75

ScaL1e1tO 44 3

COVE o ks =40

U U

t 21 i

Commentary on bar arrangement ItS 8110 ref 3.12.8.11

A-A Sc4, t:"ZO

3.12.10.2 Figure 3.24 Table 3.27 3.12.10.2 Figure 3.24 3.12.10.2 Figure 3.24

17

Columns slender and short columns

EW / = O.S (E4o: 4.5

AD TcP

4.o-

boov)

or O tv\

= I52> iS

= 40 = 460 lst

14000 15000 1j 300 300

8000 6000

BS 8110 ref CALCULATIONS ouTPur

2I2.1 5ue,-FAM A4ALi'$lS - rEje.r to bpMe.iO. UR(L4Tt c4 RsTca

cover- or U4 Co 4or4 o expo're 2o . ' 40 oooot Ikreroj 2o w... Tk' 3 4

cover 4 -..k',

tvoi 2o(a.3o xr 4Ovst*w, It4TRAL CoL-u (u..ctaii -- oof) AXtAL LOA o4 M*1P'T$ ifrow. ANALX

EAML$ k.N

COLUM Ic LoADS CGLMaMJTS k IMP0cED

E2

aa t 2 1. 2. d 2 1 2 1 2 oa 49

210 244 %33

S4 4 53 5 i4 J 133 34 4 32. sa J 9 9 100 53 3 3

3aFL 2 249

29o 117

140 U7

t3 SB 32

1B4 ivj

32 s& 3' ,

. S 37 I9 6G,7

24.F-(. 298 249

2o 117

140 17

i3 i5 32

i54 117

5 S S

9 9 14 32 b93 1 FL 3oo

252 292 120

14 liB

37 ts 134

ics 120

g 34 -

5. i4 14 873 42, 12Th U82

I 8000 I ooo

LOAD CA1

1oo1=' LoA CASE 2

(PoLr -, 1 atfecti.ve = j3 3 &

TabI 319

8l '3

N-IS (3 D.9 E4co c2.SxA.5 =

4 ,0,

1N1RNAL COLL4Mt.J (oo- t)ot.4 Ld Ca o.d z. tOO * Q' 773 7

beo4 i27 -

M1, 0, M2 S, O.4M. 7.k 04 M - O.(DW\2 = O+0x i fI4 > 7.

2 1 ( e'y tDSIx0.xl3S

.4' "T a kb') 2ooo =

DOS3oO qreLe..s o

U23x S44 2.3S < L. 22 (-' b")

M = 42> 29k, _____

oe 1. bove t oor, cvv.t oc4 a2 od, oJ:

C' t'255 L76 cN. M 4 1c,

0 - 0. x .34 = 2o.4kNr., _______ -

______ - ____ D Mow..t 204 + O- M = 4 > 358 Ti RO','SiO L0.4 i.os(2i 28i N 2 0/460 (1 0 . 9O w

BS 8110 ref. CALCULATIONS OUTPUT

t4 + 544

Po_,t t

324

33.. t

Ei 3

S 3'3 Prt I

3. 2.7 2

(b M+M 658 k. = x si = 2''9 k.

2'2 L - 5'8xi0_ = - oo '2-44 a 3O-4o-i3 = 247.

2.47 - __

- - = Q32O

O2S 4Qx.OOx47xlci3 74ik.. I. N> t- 4T'S (%oi)

=

K - _______ = O2 23-741 = .4

ioox%O -

-

fr\ cb cLa.-, Ce.ck

, _______

=

= _____

1v1 0,

Mt.

;5 k.

CcLrt 9t.2B') 3

k.

_

c247

4T'25 (tOGOIvw)

ok,

ok.

" 51. M

23.9-7

5'8 > fr2 2.o

19

--

ectLie k-S 0'S Cerc

LK= O9x

= 2ZI

0.9 (evct 0.9 x

Y= 'L15 b

CoAcLo; =

=

usiv.43 oac -

BS 8110 ref.

CALCULATIONS OUTPUT

EXTRJAL COLUMt4 (Foo R..ooF) AtAL LoA1 cd MME,.iT AL

TOTAL

u-AM LOADS k CoLuMtt b$1QN L0A CLM0MT$ k. IMPO$E.D loP oTToA4

LDAO C4E t '1 i 2 2. ' 1 2 1 2 t. C

i92 i.7 4? 4 i0 5 S4 9 98 oS SW.

. rt 247 25S U 42 4 k2.o S

25B i1

S 2a

15 95

SW.

24.

eti3e

r.o-v

c4e

1!5

247 1J2!

26

25 il5

it & 13 120 25

S 5Th l

125

t25

G1 L5 L2$

S 105

95 joS

ti7 SW

t. 245 2S3 ii V74 2&. U9 7&& 10 E'oO 4 ' SW.

24e t'25 2S 25 ii 1 : 4.02 1D54 16O oor) c

Ft (t)LCLA1)

SOT CoLM

e (.rt PSQc S

4T2B C i90 P%

I3\) top., boo3) CD4Ov

=

EO

S399 Por 1.

PrI I

N Osx oO+44-cY924O O5S k,

fr\ z

Asu c 300- U8 N11hi7xJO 4.3

- 237 - 079

-k-- oo 0osc. 2

= '2.3, A5=.2o7o

B.o' 1st.c,+fa4 'i (4T' i%D2)

20

154, ;

iS kN. 7 k1L b

I(4TEiNAL COLL..U1M F'2 ExTR.AL COLUMN Fl LLv,k,

J VertcaS it.rs

-;------ ----f--

Ltrvk_J Vt.ai Se4o, ? c (1

.

.

-

4

Y9J 4 4.

COV.R t0k'= 40

.

;4

:

-4 i I coR t,

.

F c-I L

-,

;1

SCALES i: 5O j 'ZO -

-

The presentation shown above is schematic. This tabular method adapts readily to element repetition. The sections are shown in their relative positions adjacent to the vertical reinforcement. Main bars, area> minimum 04% bh. Slope of crank at lower end = 1:10 maximum. Crank offset = 50 + 10% =55 mm. Minimum crank length = 350 mm (140). Length of short projection beyond crank = compression lap +. say, 75 mm for tolerance. Reinforcement area at laps < 10% bh. Bars project above first-floor slab level to provide a compression lap above the kicker. Bar projection = 35 x 087/095 x 25 mm + 75 mm for kicker = 875 mm, i.e. compression lap = 800 mm.

2 A single link is provided, since each vertical bar is restrained by a corner. Minimum size = 25/4, use 8 mm. Maximum spacing = 12 x 25 = 300 mm. (R8 @ 300.) Cover to vertical bar = 40 mm> 15 x 25 = 375 mm. Links extend to underside of floor slab. Normally, starter bars are detailed with the footing, as column F2. It can be economic to detail starters with the column above as shown. In this case it is advisable to schedule the starter bars so that they can be processed together with the footing. Note with this detail that the section at mid-height also applies to the starter bar arrangement. The starter bars would be shown dotted on the footing detail together with a suitable cross-reference. Bars project above the top of the base to provide a compression lap above the kicker = 35 x 087/095 x 25 + 75 = 875 mm, i.e. lap = 800 mm. As bar mark 1, but bars provide a tension lap above 1st floor kicker. Cover = 50 mm. Clear distance between adjacent laps = 100mm

Foundation reinforced pad footing

BS 8110 ref. CALCULATIONS ourPuT

Tob{e33 4 URAbLITY )Assoi.i roder4e*pesire '0 . U se. ow.sat 4o cover No..sd cover 40M,l.r4$ LOADI.JC - '1 (iet paqe19) De.4 I&.e'1 r0t.kN. ICxr CIu-ec 12.7 718 1's1

127/i,4=D =443 I58 /,(toi 0kN/v etr ov roFk concete 4or4.foa4

. P,.4 r9uw4 5YC2OO -10) = 7. s .. Acio,t 2'7S rove4 = 7.57fw

U.L.S. Dtcv. ressu . 2Jo3kP4w

.4.4.4

. o6t.v aoco1uw' 63x 'i.7S 2 = Avers c - c,o-4o-z5 =

fr\ 3x 0' 0.017 = 4o,27S0xS52 543x 10' 244Sw :

o.954xO.9SS35 (Q5122) 44 3.i.3.4(') 4

3 113 4(2) 3L7.2

ULTIP.4ATh SAR Co4.or I Sk

- V4f . t91 fI3751so%s) :ookM 2 1375 , r V . SO'IO' i5o 's.3S

force V 4n coLa.= x f37s-a'so-2xS3S} i . k4 2 1375 12.

V 't " 27SOcS3S Co4.or 2 p L4.v S\Qr) *.e ore. cka) V 1O SI

T

.4

A

_J2O-t- &5OI

PLAN

4T25 -2 Cover =40

Mn,.

2aB--3oo I ;

COVER. BI 4O 2\4

-is A A Scak, i:SO Commentary on bar arrangement It 81 1() ret Bir rnark 1\oles 3.12.8.1 1 Straight bars extend full width of base, less end covers. Table 3.27 Bars should project a minimum tension bond length beyond the column face = 35 >< 20 = 700 mm

< 1150 nim OK. 3.3.1.4 The underside of base is concrete blinded, cover = 40 mm.

Column starter bars are wired to bottom mat. Minimum projection ahose the top of base is a Table 3.27 compression lap + kicker = 35 x 087/095 x 25 + 75 = 875 mm. i.e. lap = 800 mm (see p. 21).

3 Links are provided to stahi Imie and locate the starter bars during construction. These are the same site as the column links above.

23

460

ist 175 -

4000 250

900 14300

Shear waD external plain concrete wall

BS 8110 ref. CALCULATIONS OUTPUT

.94.3 14. 2> 2 WALL

T&bk 33 )PALtT'( Ft $TAC NS ccvr ( svexe. x?ocLsre. 40w, () LL4 . '20

F-y- rest&-e 17 kAI = i.2> t4oLsr 4o 2Ow.wt.

, lc.rt ye stc ck.. C.

O.S(3Z3+8.S) 49.5k/ 5Q V3t O.7(24x1E GS.1 C&ct.c c4 1t4.kJM

a,.r+x4xO.8') 27.8kN/. ;. c4_ BS (99 CLf 2 0

B 8110 ref Bar marks Notes fable 3.27

3.3.1.4 Table 3.25 2 3.9.4.19

Table 3.27

3

4,5,6

3.12.3.4 7,8

9

Wall starters match vertical reinforcement. Minimum projection of horizontal legs beyond the wall face is a design tension bond length = 35 x 182/377 < 12 = 203 mm < 287 mm. This provides the footing reinforcement. Minimum projection above top of base is a compression lap + kicker = 35 x 2 + 75 = 495 mm, say 525 mm, i.e. lap = 450 mm. Underside of footing is concrete blinded, cover = 4(1 mm. Minimum longitudal reinforcement provided. Minimum vertical reinforcement. Area = 254 x 1000 >< 175 = 438 mrn'Im. (T 2 @ 300 EF = 754 mm2/m.j T 12 bars provide reasonable rigidity for handling and help stabilize the cage during erection. Minimum projection above top of firstfloor level is a compression lap + kicker = say 25 mm. Lap = 450 mm. Minimum horiiontal reinforcement. Area = 438 mni7m. (T10 @ 200 EF = 786 mm'/m.) Provide at least a tension lap = 35 x 0 = 350 mm. say 450 mm to satisfy shrinkage and thermal requirements. Bars are placed outside vertical reinfircenient to provide maximum control against shrinkage and thermal cracking. Those bars in the wall 05 in below firstfloor slab act also as interna] ties. Tension lap 6)r tie = 35 >< 10 = 350 mm, say 450 mm. Peripheral tie at first floor. 1,bars at either end provide continuity with edge beams. Laps. say 450 mm. Wall spacers maintain location of each face of reinforcement.

25

Commentary on bar arrangement

Staircase 3500

end-span continuous slab

175

5060

BS 8110 ref. CALCULATIONS OUTPUT

3? T.$ Ie 3 4 RLVrt 4 RE.1STAI4C. c'- .toor ri ) o. z

LoA4 Ave.rMe ctb L c.e.cc o.k... = 2so

.0 = 05

cZt.c ce4 SoaA .. .5 k/ = 4.OkJ3/ (14GS 1.4.o)5.o = 17.5kN/1k

k Q, S kN/ k 4.Okt/ F T3S .4'I 1tivtor SLLr= o.itFL= Q'11x77.5x'O 43.

TI1AT .Ms eo r4et O = 3$. 3Id/M. E

L2Q

w*st 44

To.bte.38

4FOR.CMeNT 1\ jsL. .i-.ter.or sc.pport. , 2 0.049 = 04

43.1

Table 3.27 1,5,6

Table 3.25 2,,9

Fig 3.25 3,4

3.12.10.3.2 7

Table 3.25 10,11

34 Tio-E

Main tension reinlorcemcnt. Lap lengths and anchorage bond lengths = 35 x 12 = 420 mm, say 450 mm. Laps arc located to facilitate likely construction sequences. Similar for bar marks 12, 13 and 15. Secondary reinforcement. Minimum area = 00013 x 1000 x 75 = 228 inniim. Use 110 (a) 300 = 262 mm/rn. Main tension reinlorcement over support .50% curtailed at 03 span, remainder at 0 IS span. both measured from lace of support. Similar for bar mark 14. libars provide 50% midspan reinforcement in both top and bottom at end support = 05 >< 571 = 286 mmlrn. Use 110 @ 15(1 = 524 mill/ni to match spacing of span bars. 1.ap, say 450 mm. Optional ruinfoi cLnlent Minimum ULd = 228 mm Simil u for h ii mai k 16

27

Cove.r

FUCHT '5' CCVE

Commentary on bar arrangement BS 8110 ref Bar marks Notes

Column design chart

28

CJ E E z

0 z

Rectangular columns

50

45

40

35

30

25

20

15

10

5

0 1 23 4 5 6 7 8 9 10 11 12 2 44 - 4 :3

M/bh 2 N/mm2

fcu 40 460

d/h 080

nformation from the Reinforced Concrete Council

Spreadsheets Many of the design principles used in this publication will be covered by spreadsheets for reinforced concrete design now being developed by the Reinforced Concrete Council. Versions for both BS 8110 and EC2 are in preparation. For details write to the RCC at Century House, Telford Avenue, Crowthorne, Berks RG45 6YS.

Buildability and whole building economics It should be stressed that the structural solution presented in this publication has been chosen for the purpose: of illustrating analysis, design and reinforcement detailing principles. A typical building frame accounts for only 10% of the whole construction cost, but affects foundations, cladding and service provision. The choice and details of a building's structure should reflect both buildability and overall building economics. Analysis of these factors using a structural optimisation program* or charts from a publication** suggests that a flat slab alternative may save around 2% of overall building costs and ten days' construction time. Similarly, rationalisation and simplification of reinforcement will normally speed construction and hence reduce overall construction costs and programme time. Excessive curtailment and tailoring of reinforcement to save material at the expense of rationalisation will prove counter-productive. These aspects are currently being investigated at the European Concrete Building Project at Cardington, and will result in the publication of best practice guidance. With increasing emphasis on the cost in use of buildings, there is a trend towards the use of exposed soffits for passive cooling. This move to whole life costs will modify the optimum solution, and deep ribbed or coffereci slabs are a favoured option to meet daylighting, thermal mass, ventilation and acoustic requirements. * Concept - a computer program that allows the rapid semi-automated choice of concrete frame while considering whole building costs. Produced by the Reinforced Concrete Council. Available from the RCC on 01344 725733. ** Economic concrete frame elements - a pre-scheme design handbook, based on BS 8110, that helps designers choose the most viable concrete options. Produced by the Reinforced Concrete Council. Available from the ECA on 01344 7257U4.

IBC

Designed and detailed (BS 8110: 1997) J. B. Higgins and B. R. Rogers BRITISH CEMENT ASSOCIATION PUBLICATION 43.501

OBC

Cl/Sf B (28) q4 (K)

UDC 624.073.33.012.45: 624.04.001.3

(Ofl@rete