BQ7I
Brifish Ceiiieri Associahon
Designed and detailed (BS 8110: 1997) J. B. Higgins and B. R. Rogers MA, CEng, MICE
This document contains 32 pages OFC
For a worldwide and up-todate literaturesearch Ofl any aspect of concrete design or construction and related topics, contact the BCAs Centre for Concrete Informationon Dl 344 762676.
43.501 First published 1973 Second edition 1986 Third edition 1998
Published by
British CementAssociation
Century House. Telford Avenue Crowihorne.BerksRG45 ÔYS
ISBN 07210 1541 7 Price Group F © British Cement Association 1998
Tel: 01344 762676
Fax: 01344 761214 Website: www.bca.org.uk
All advice or information from the British Cement Association is intended for those who will evaluate the signiticance
and limitations ol its contents and take responsibilityfor its use and application.No liability (including that for negligence) for any loss resulting from such advice or informationis accepted. Readers should note that all BCA publicationsare subjectto revisionfromtime to time and should therefore ensure that they are in possession of the latest version.
IFC
Designed and detailed (BS 8110: 1997) J. B. Higgins and B. R. Rogers MA. CFng, MI(I
Contents
Foreword This third edition ofDesignedand detailedhas been revised to BS 8110 : Part I: 1997, and the amendment dated 15 September 1998. Althoughthere havebeen several amendments to the code since 1985, the latest and most significant change in the partial safety factorfor reinforcement m from 1.15 has been the reduction . . to 1 .05. With higher stresses, less steel is required. However, the total saving may not be fully realised becausethere are other considerations such as choosinga practical arrangement of bars, and the deflection in the case of shallower
2
Introduction
3
BS 8110 and limit state design
6
Design information
7
Structural summary sheet
8
Floor slab
members.
10
First-floormain beam
The calculations have also been revised for the loading requirements ofBS 6399 Part 1: 1996 and Part 2: 1995.
16
Edge beam
18
Columns
22
Foundation
Designcharts in BS 8110: Part 3: 1985 may still be used to providea conservative solution, and one ofthese charts has been includedfor the design of columns. Lap lengths for these members have also been takenfrom BS 8110, Table 3.27, but adjusted for the design stress of 087f.
24
Shear wall
26
Staircase
28
Columndesignchart
29
Further information
.
The tie reinforcement for robustness is designed at its characteristic strength. If the characteristic bond stress is used for calculating laps and anchoragelengths, then the values in Table 3.27 may be multiplied by I 05/l4. This publication takes a conservative practical approach and usesdirectly the values given in Table3.27. Observant users of previous editionswill appreciate the skill that is evidentin the 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 artworkwas meticulous. Sadly, he never saw the second edition in print. I hope that my amendments to this thirdedition 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 purposeof 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 pLihIications.
BRITISHSTANDARDS INSTITtJTION Siructural use 0/concrete. Part I . Code of practice/ordesign and construction. Milton Keynes, BSI. 1997. 120 pp. BS 8110
Part
I:
1997.
H MSTATIONERY OFFICE. Building and buildings. The Building Regnlation.v 1991 (Amended 1994). HMSO, London. 21 pp. Statutory Instruments No. 2768. BRITISHSTANDARDS INSTITUTION Loading/or buildings. Part I . Code 0/practice
br deadand inposed loads. Milton Keynes. BSI. 1996. It) pp. BS 6399 : Part
I
1996. BRITISH STANDARDSINSTITUTION.Loading/or
buildings. Part 2. Code 0/practice
Jiir wind loads.Milton Keynes,BSI. 1995.82 pP BS 6399 : Part 2:
1995.
/ir
BRITISH STANDARDS INSTITUTION.Loading buildings. Part 3. (ode 0/practice loads. Milton BSI. 1988. 23 pp. BS 6399 : Part 3: 1988. roo/ imposed Keynes.
/r
BRITISH STANDARDS INSTlThTIO'J. Specification /or scheduling, dimensioning, bendin' (111(1 cutiin' steelrein/irceinent/r concrete. Milton Keynes, BSI. 1989. 20 PP BS 4466 : 1989.
/ir
IIIE C()NCR VIE SOCIETY. Modelprocedure the presentation0/ calculation,r. London (now Slough). 1981 . Technical Report 5, second edition. 18 pp. THE CONCRETE SOCIETY ANDTHE INSTITUTIONOF STRUCTURAL F.NGINEERS, 5iandardmethodo/detailnig structural concrete. London. The Institution. 1989. 138 pp.
BS 8110 and limit
c:)bjective
state design
To serve its purpose, a structure must be safe against collapse and be serviceablein use. Calculations alone do not produce safe, serviceableand durable structures. Equally important are the suitability of the materials, quality control and supervisionof 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 satisfactorilyduring 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.
Serviceabilitylimit states
Ultimate
Objective
limit state
Deflection
Cracking
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
Design ultimate
Loading regime
loads
Design service load
Performance limit
Deflection should Crack width Structure should not exceed should not not fail exceed 03 mm specified limits
Characteristicvalues
impair usage
generally
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: Characteristicstrength = Mean or Averagestrength — L64 X Standarddeviation 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-expressloading 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 seriousnessof 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 achievingtheir maximum value at the same time is less. The table below gives the partial load factors for the ultimate limit state.
Partial safety factor to be applied to Combination of loads
dead load
14 14 12
adverse heneficEal
10
16
10
—
—
12
12
12
1)
with imposed
Deiiçn strenqths
wind
load
when effect of load is adverse beneficial
1 Dead and imposed 2 Dead and wind 3 Dead and wind
imposed load —
—
14 12
The designstrengthis given by the equation: Characteristic strength [)esign strength = —______________________ is a partial safetyfactor on the material strength. This factor takes into account the variation in workmanship and quality control that may normally be expectedto occur in the manufacture of the materials. The values of to he used for the two materials when designingfor the ultimate limit state are given below: where
Values of
,
for theultimate limit state
Reinforcement
(oncrete Flexure or axial load Shear strength without shear reinforcement Bond strength Others (e.g. bearing stress)
iOLisiuest
4
I .05
IS 125
14 15
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 elementswill not lead to a major collapse. The Code requires that in all buildings the structural members should be linked together in the followingmanner: (a) by effectively continuous peripheral ties at each floor and roof level:
(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 reinforcementmay be assumed to be acting at its characteristic strength with no other forces present but the tie forces. Reinforcementprovided 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 reinforcementfor the usual dead, imposed and wind loading has been found, a check can be made to see whether modifications or additions to the reinforcementare required to fulfil the tie requirements.
Durabflty and re resislance
At thecommencementof 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 influenceupon 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 dimensionsof 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 minimumgrades will generallyensure 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 serviceabilitylimit 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 deflectionsand 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-depthratios. This can he checked before the reinforcementis determined, although some engineers may prefer to followthe procedure where the check is made after thereinforcementhas been found. Simplifieddetailing 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 envelopeand be in accordance with the general recommendationsof the Code.
5
Design information
Client Architect
T
LIL14 5SiO
TLe. 'a,
Co#.ai
W
Engineer responsible
BRJZôers
/j,
tnj LP
'j. S7 of2 Cocre.tc Past IO5)ckr PCU B8
Pout
Building Regulationauthority or other and Date of submission Relevant Building Regulationsand Design Codes
Intended use of structure
Lbon
Fire resistance reqLnrements
5
Roof
F1'oo
irvoecj
Sjr-
C°) &ct tL3r
4.QkW/ 4O k4/
LXc Co4 Fors a Speed Factors
2 a/ec (basic
Wind loading ccnditrons
S
S +O(*r.') Co'84, C ,.ç, 105 Sb = 171,
4
e.'Jere.
1.0
fs
,r-A4e.
o
4o wt
L.
Sdf AU
= 1•
S
O
O•3((),C_r=QO2S
(Vd ('i€xaS) (S6llOTcie3.2) 2oo
,
k4 ov wcik '20.
strek --
Foundationtype
Material data
(€IIOTcIb3.)
a
1iJ'c
•'
wet
fL
4o
4'ok4/ S-oir,. ov
Exposureconditions
Subsoil conditions
- v\O AoLjo, beac rreure R1c
General loading conditions
ore
Other relevant information
Structural summary sheet
G 5ooO=4oooO
t,
AU CoCa
z,
0
,
11 fl5
0-I
S
S
S
-l
Mbean bW4w
oox3oO OOx'oO
SO OO
wall
0
T"{P1CALLOOR PLA4
175
3
W1 t5-rAI4cE.
IiP w orce ré4 e4A kax- vodk. . brGctrcL EW kor i,
T'-(PICAL cRoSS-
C'TtoJ.
SJe: ICryo,, CoS,$.275Ox'l75OxOO C
cPc
C-
eA
Lr
prviAed.
or.
C
br4 /u—i, o4 r4
- Perpcc ;te It.— P
Ir.
a-
rEt,
w—
w C
C
Tia 3 1'2..4.2
-3
C
>< P
/"44
Ft
cc PRVSi C
C2o4\0)
-
= 2Q+lG
C
ter e wc
C
3G(Ok, 7
Floor slab interior-span solid slab 175
5000
BS 8110 ref.
T3.?,c3
CALCULATIONS
ct REITA4C ov hr U4 CovCt.ov of
DugPB%t.vr' 3
W.L4S4
34
Mo.xre
FR.E
(G4t
F
3.r.2,4 Tb(3,12
Dgvtoati
32.4
ULXIMATE
Iraror wct
4.44
)
toc.d
O.95
0.22
lc?x 14S
6k
DLaC.T(oi.4
2o4d0',.- 031
. Atlte
0 0Th
(buto.x1494s: Top&otow T12. 0o
cr or WOr
(iiJ)
-
M/w
rio /4faeq 2x4(O33O
ok.
=
3 x 317
I4')
Tok3•IO
2O.4kh/ =
O.9546Ox14l5
o.S4.91O3'
PA
=
204x1&
PA
Cdr5cear TQ6k
i
)=
1
re.L.'.ft.
'21.5 5000
'I
149
,(
3.12.3.4
r
PV(op..J
T€orce TAbteZ7
4t(
7
4S.x lo 44,0
—
OC
.,
5
- 33
$(o
•,
447
2U.27 CR.Acl(ii bt.twee. bo.r p-cj k 11 2oO
'2o si.
4.7kN/2 401
3k F
4o-1ox4S2 oc'23
..
r
4. okN/
2o.4
= i4s(o.S+J(o.Z—
Tb(e8
c)
=
o.oC,3F =0.OCx,43x5O
k
cover
4.7kt{/
=
t.1r47+ 1.x4) 50
/Vs r.spo. 4.DrtS
.ik
4.2 0.
Cpa.ge
ppor.
A5--
1zk>
x 24
O.17E
FCEfrT t4
2o
o766tbk 2Ocovt
LoA
Iable3i2
OUTPUT
12
rttQ. cJck.4
34
( 4t)_ :#3oo.
o..ct4We5 ITR..iALii
Ft =
.
r4o oc.
c.*j k.
ak..
3kN/.wd
4r.Lw>Ft
-'fl'
T12.e3oo (377
)
Al 1.
i,TIO—c—30OTQt I
tso.l.
"
T
i1loo
5T10.-41 2)00 5Tt0-5JT' Mt.
4
—'
-
—
II C3*'Z)
—
.1
'2
I U-
B
1oo
L
—I '1
1
3
4
STtO -51 30O
5T10-41r2 It,
1
I I
S-rto--3GO'r2
@_Th
L
—
I
T101300 7 TI 0- e2 AlL
2
i_ I
(2+3)
(2)
—
L%o 1
8T1O-2.00 '7T1O-3)2Mt.
'z)
_i .J
F 4T'2-1- 300± P LA.1
(r4 '2 ovfte4
A It
r c[ti) .45s
AR. = alecY4J
&r5
Att
,z tt. -
A-A
CovE.R
toote
5= 20
$cale; i;o—-
Commentaryon bar arrangement BS 8110 ref
Bar marks
Table3.25 3.12.11.2.7 —
1
3.12.3.4
Table 3.25 3.12.8.11
2,3 4,5
—
7
3.4.1.5
6
Table 3.25 —
3.12.10.3
8
Notes All bars are labelled in the form described in the Standard methodofdetailing 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 positionsofthe first and last bars in a stringare indicated in plan and section. Intermediate bars have been omitted for clarity. Minimumarea of tension reinforcement= 00013 X 1000 >< 175 = 228 mm2/m. 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 Main tension bars Tl2 @ 300, A = 377 mm2 > minimum 228 mm2/m. — OK. If curtailed, A = 377/2 = 189 mm2 minimum228 mm2/m — not OK. Bars lapped 300 mm at bottom support to provide continuous tie.
<
Secondary bars — use T10 @ 300 (262 mm2/m). Minimum lap = 300mm > IS )< 10 = 150 mm. Lapping reduces bar lengths for easier handling on site. Laps are shown staggered for effectivecrack control. Minimum transverse reinforcement is placed across the full flange width of the edge beam (minimum width = 650 mm, see page 16). Minimum area = 00015 )< 1000 >< 175 = 263 mm2/m — use TlO @ 300 (262 mm2/m). Main tension bars over support 112 @ 300 as bar mark I. One curtailment shown at 03 effective span from face of support. Further curtailments prevented by minimum area and spacing requirementssimilar to mark I. 9
f
First-floor main beam
=460
tto
............. 8000
two-span flanged beam
300
6000
BS 8110 ref.
CALCULATIONS
.2.I.21
AL'-t'5
Ljs
Su.FR.P1ME.
A
taa.r ett. er rMrv
forces.
F-or
OUTPJT
t
S
'
e'
e.LLa.r ro4kcgd
tD
be 4 tse be(oi C
ç-1oo
b
co(s.bosje
3,34
c w ot prove rot rcd rert. to b sc-ur wcAk. D CG F Ri vt t.ov of eposurc - 2o. ov1 cove for?OO
.2122
LAPD4G
&iiiwecL to be çxed. 1ve. Ti. t'i.ov,. 1L4 a-re. Lart* takcr
•3 To.bk6
STA
co
COVW
wbefor
p4 toc o75o.b CPe&) x 24 se-ieLt (o.—o.r7s)o.3 oGa.w
Mv ce
Bi
Moie.m
.Ove4tl.Q%
i4 '(2
o4
()
17$
+ +
ba
2O
+ 4o2
oo
24 (8't'2 2.7(
4-it7
4-
4$
1-
e4
2B.kW/,
103K
'i& k/s
+t
2S&k4/. 2OOk/t.
Oc t.4 .i2k/M )
—
33
—
22
—34
+ Qc
348k
—2So
17
------
Ctk I 1oo4
wp
LtperCowC. Lower II
Scur 28
-
4
+ 'a-
#1's
3
i'2o
+ 1%
1' 12
+ 2o4 -
+ 2' 10
'2•3
2o.Ok4/,
+ 32
—
2$2
-iii .54
2.S
+
B¼A
ii
-19
(.B) = £x4
Ii4K5
20
uie.4:
cZUIL4 rowv AvJ
I -
5c4.7— =
t
cover
(k)
CASEJ1
CM
IS%t
Lij*- Cokiv ower
v#
sc-0- (1)
- 52 - 4 Ler CDiLAIstf, 1
0
se (-!)
CALCULATIONS
CASE
I
17S
402
II II
o
III
{1
34
o
.5S
40r
ii') ( —O')
(SQ..e
1 S2 (I)
2&L
(—2o'J')
eatA. -UI
I trbut&i La6t wecoçc
L
32S
..NvLOPE
MDN-E'JT
2? I 22
I
3511
00m.
EveLop.
Rrnto V
2BBR
oao
3001
•1
FogcE
I E1LOPE
I L
BS 8110
CALCULATIONS
ref.
Mu
t.FLOof
3EAM.,
:vta.-vt Suçpor:
Fcor. ?JL K'
/ct
bd2
efoe /O.4,):. /c
-
0104 . 4o x oo 442. 0.95 4ox o5 44O
S%
.
Ef. f[aewtL = 6 =
x O•7
4
(Q.2
3
+ 232
As
440
Ma
J__
I,
Lj4co
2 T 2B
3o0 Co
0.02'3
4Z0x4So ______
-
0•4S
0.5x4Ox0.9Sx4SO
— —
so
4T 2
(tO
t756
E
tc...o ".
i55 k1
i5x tO 40 x OOx 45O
(O.So.
..
1—
42O
+ Q. t4 .'< 9000
.M.evop€11) =
—
a
4T25
1685
1O
32. < 10
-
A5
=
°')i,xtO :.- Ø.4) D2
0.4 O.O,4
So
-
2T25
cl
657 MAM
O'Sx4,0.x0.9rLx 450
__
775 o'S.c.4Ox4S1
ckovcbox: 312'32'2
=
M
4d =(o,s+Jo,2-oo.7> o•s
FroM
22
A1
Frot
(. .3
—
0'5 4(0 C440-5o) o (oo 5oo)/
s'. t&or
o.io4
O > O7
50 i-0•4
0. 1o4') x 40 x 00 x 4402
Co. t21 —
C'tgck
2.2.1
282
=
= O.4o2(0.7O.4')_01(O.7_Q.4)2 = 4oxooi4.4 Ot21 > O1o4
K
r32
E')
Q1 = 0.7
322t 3.4.4.4
OUTPUT
75 xto
190x
..IC.b4rcksr=
S0/5)
2 x4o,( '25
M
Frv .Vf. Cvveloe M
0.s
=
46o vw1
jnPoo )25,, a.6
3.4.j.
E. M
.M.evei.oe, .
=
cu A
—
.OO+ 0.14 x (,00O
OO7,
Abt9e4
we.b
-se. 12
0
13x 10 4So 4o
Ce4c or-.oVe.r
1t40
=
o.ooK300X 500 =
Spport,0.002fx3Q0oO=
TLc
&s
2 T 2S
2
(8lr. 0
t&4%SLO
BS 8110 ref
CALCULATIONS
SkEAR REll4PORc€MEJT
34.G
tior, re.L,, Ccve. 4ooA - 100x2 0•73, b OO4SO
T.6te3'B
'
t'vvk
TóIe7 2 45.5
Tbe37
A =
0•75
OOx 04
oo
A/
o.•7s
j
V.f.d 8LM 2t
34..1
bkto
t
CAC '2.t1.2.
\'L4.
T'VLOY.
& €xtr-.f sport
I2124
I.e.raS $..4por-t
2i2
e,
3t2.3
TIE PRO\, 0.
Tv\.trJ = F (
sro Si0
(K) 7
T
2o
Lap
xe-r
40 < 203 100
1 o0
0
<
<
<
35
< 92
10
po
(e aae 7)
7.
(
=
I
uefa- 4
3S< ('s2)
ioo<
L5
o
c'r o
:c-.k
2S)
-S2 L'e
<
oc;
D2rS
'
coLw
41kN
o
.
(va.4Q,
0O3
7QkJ
Coa carKe
473 x
2
0r€.a4L,
0L
ca4o2<
ct;
J
4.+4.O
15
1
-
< 55
3k/
or forCe
0I5
35
-
4
f -
Co
( -sF
(J) 3,%
-
< 125
100
0
T
etee d-t
4
pa
0/ + 18 — 30
,
.
1V\
—
3oo
224
I
T
R..t'2. @
23/2
&000 450
ba
G'&x S Cvw
b
Acto
rk
F tLC
2x 4(oOic I75i27
-
12
i
Ay
O.'9 O.7
3x 1%O 325
i..5
'.
Tcb3'27
•2S
42Ox4SO2
ctor
Tk32g 3ViII2
.o3
b-Lo=
M
3.4,
j•sc k..N
1t
Lks 0•% tlS R'l2C. 175 tSS R. 2 3O.o j.14 •37 p.51 R 1 300
•'32
V1G875
b
T.bIe•9
J
.50 j
j(oo
2M
FLECTION1
io
2
V/N/ vv
25
R.L
/
00TrR2oo .(vO7O4.o59/2 0'
4B0
2
L.H
312•3.i
'
Skct R12
,,
2 &t6
0S7(-
\!c
OSS(2O
3oo
Loao
T6137
4•S•tO
d.4SO
2T2 (82 w2)
0.4
6
Sv
Lk
Tobe7
3
OUTPUT
04
xteJ
t II
c,2R12
- 11
i4eoO
A 5
—
'ZTi6- G
2 '2T2,-2
t '12 t
A-A -
:
O___
ba.c o c1_ xO.95[j] bdxO
For =
a
4
Top: b=300, Bt,n: b 1420>
ELE VAI
4
r
.stcxxce
M= a=
/4o.9i2)MJ7 = 0., M13'5km.
M o 2T2S ('3&2
O.5fx4x, —
4LY Mo± Ev.ve1opii.
1o
&
(3.4.4.4.)
____ _____
l_o.I_
1s
'75
153kNn
Extntot QIon4 T.C.P(3.1,S
bOO
a.
2)
b C
CURTA1LMT DIAGRAM.
=
cL450. 300. (. t€.Lo. ct. 5Ø = /I€T.C.P to pt, we4- M
2
Commentaryon bar arrangement US 8110 ref
—
Bar marks
I
3.3.1.2 3.12.9.1 3.12.8.14
—
2
3.12.3.4
— 3.12.11.1 3.12.9.1
'4
lius beam shows loosesplicebars at each column intersection. Ihis met hod simplifiesdetailine and 0sing and the span cage can readily he prefabricated. Tension bars arc stopped 50 mm from each column lace to avoid clashing with the column bars shown in section A--A. Nominal cover 20 + 12 32 mm > 25 mm, say 35 mm. Remainingtension bars stopped off as shown in the curtailment diagram above. ('heck masimum amount of reinforcement at laps < 40 breadth 4 >< 25 = 100 mm < 0-4 X 300 =
3 —
Noics
4
5,10
12))
mm
—
OK.
loose bars arc fixed inside column bars
as shown in section B—B. Although designed as compression bars, these bars also act as internal ties and lap 1000 mm with the adjacent span bars for continuity. The two tensioil bars are stopped 51) mni from the column Oice to avoid the column bars beyond.
'
loose I—bars are bxcd insidc the column bars and provide continuitS for column and internal ties. ('heck minimum distance between tension bars 25 mm (aggregate si/c 5 mm). 30)) — 200 -— 100 mm 25 mm — OK. Top legs propect from centre-line into span. minimum dimensions shown in the curtailment diagram.
f
1
M A1P4
EAM
cer LNK DARAIY\ 3.12.3.6
3.12.8.14 3.12.8.3 —
Bottom lcts lap minimum 00)) mm with span bars to provide continuity for the internal tie. + 450 1315 mm ) let both legs 'lop 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. 535 450 05 mm ) let both legs 'lop legs Bottom legs 20(1 1001) 1200 mm ) project 1200 mm. say. Else r 4d minimum radnis bends.
5
10
-
'
—4-
3.12.8.3 —
6.9
link hangerbars arc same length as bar marks I and 4. Bar is onesize largerthan links(n' inimum 12 mm).
3.12.9.1
7.8
'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 B—B. 'Ihese bars are bundled vertically in pairs to reducecongestion andthis also allowsa gap(ninimuni75 mm) for insertmii of a vibrator. ('hosed links, shape code hi. are arranged to suit the link diagramabove. Opentop links, shape code 77. arc not suitable for the sites shown. Note that links it laps are spiLed at ilot greater than 200 mm since cover I'S bar size.
3.12.4.1 — 3.12.8.12
II
15
Edge beam interior-span flangedbeam
1=••••• '350 t
f
5000
300
BS 8110 ref.
CALCULATIONS
DL,RAILITY NDw2aJ Cver
To.bIe
33,34
OUTPUT
'S1iCE
FIRE.
tjqr
Ovc cf ex?oure 3OOwde. be.4 for
ir.ero
LoAi
Ie44
444 t.rLor
OO&xt?x5
M
O.07
E
os:
0'O)
-
Cu
40X650x2902 002.,
bd
'
o.is
3oo,'2PO
/
v
Tcbk7
M. L.j
4.'(.1
ZI0P4 AS/ O'75>2&O—&C2OOMs' Sv
D,FL.CT%O,.J
1ce3
2Moft.a,. M -
Te,g •.
2T2O
1
fi*4or
CAc A(oJb
Tcbe
T0p
OFO rs
d&rcpczc
QvJLQ CtE'oe 5.Cj'%
= o.4,( 300
vri
-
o•Sx2O '200
0'
i
(4o2
0.G3N)
R.io€200
1
- O.7> Oi
tLccgct.
b7b_ o.4>o3)
2 x 4o
272N/rn
= 22 x
ooo
17.2
2O
k.
.'.
27/ (sedeco) 7o 2g \9>1s 2 ar5o chkC ok 41000 220 rdtsre
=
2L
,1
CC
O0
. -eLF4. A5j 4t= . x74 45 3oc
TIE. PR.oVl,O4
U'L'Tt2,
=
2C)o
153
s&r/cff.dLp rto
l2cI.2A
5BxD
3x 4o2
1
3..U
2w
ob0
OO5
3oox2.BO
22o
44L.C
43.SIo' 5ox29O -
,1Aow*bLe.
oiIc27
4S
O.OkW
fc'ot reforea.rc2T20
G8'75_(D. I+ 0.28) 2S
'Larforce 1oo4
(.2.4
12Sx
43.9x
A
SrorceO5SF*1•2S6875kN,
4;,Io
3.12
2.s•okM.
125.0kg.
0Xi0 442. fj A:o5,46OxO'S7x2&D (o.s+a;J L.jio. M4-Ltcuy; e.fewi4t = .LJ—4O
3.415
)
k= QO.7kJ 2•Ok. k= F =i'zsok.
o-7kL
5Qx0' 4ox oox'2So
bd2
4O%W%
6-3 25.0
544o
M.oo8F€
/vLLMtA Co/e.r
4OøA..
294
ose4 i osab(p.t W'25
byi (o.4 ULTtMATE .M'S IrorsorC Wtt4—. a:
TAb(e..35
Taá'5
2x2
CooA 4!rov
.'
=
,coc
I
To
-
'ZTVZ.
'23R40—5-200
A1 2 T '2O
4
n
je-co
-75
iot
EL EV Ar
A
44 3
ScaL1e1tO
COVE
o
ks =40 t
U
U
•21
i
A-A Sc4, t:"ZO Commentary on bar arrangement ItS 8110ref
Bar marks
Notes
I
Horizontal bars in this member provide the peripheral tie. Minimum lap = 300 mm. The two tension bars are stopped 50 mm from the column lace to avoid clashing with the column bars shown in section A-A.
3.12.8.11
3.12.10.2
Separate splice hars are fixed inside vertical column bars. = 03 x 364 = 109 rnm. Use2'T 12 = 226 mrn. Minimum area = 30% I ap = 35 >< 12 >< 109/226 = 203 mm > 15 x 12 = 180 mm < 300 nim. Use 300 mm lap. Link hanger bars also provide support for slabtop reinorcenienI. Minimum area = 20% sI1pT1 = 02 436 = 87 mm. Use 2T 12 = 226 mm.
A
Figure 3.24 Table3.27 3.12.10.2 Figure 3.24
3
3.12.10.2 Figure 3.24
4 5
A
x
Tensionreinforcement over support is fixed inside vertical column bars. Bars are curtailed at 025 span from lace of support = 025 x 5000 1250mm > 45 x 21) = 900 mm Closed linksare shape code 61
17
•
15000 1j
14000
Columns
= 460
= 40 lst
8000
slender and short columns 300
300
6000
BS 8110 ref
2I2.1
CALCULATIONS
5ue,-FAM A4ALi'$lS -
ouTPur
rEje.r to
Tk' UR(L4Tt c4 RsTca 3 cover- or U4 4or4 o expo're '
ooootIkreroj
AXtAL
EAML$ k.N
t
2
oa
49
244
3aFL
1.
2
9 100
249
117
U7
24.F-(. 298
2o
140
117
17
249
t3
37
i3
I9
32 37
liB
5.
1B4
(PoLr -,
873
42,
2
34
4 3'
6G,7
5
i54 117
N-IS
b93
ts
ics
134
120
g
14
12Th
U82
= j3 E4co 4.o(3 c2.SxA.5 1
D.9
=
8•l '3
/
=
O.S
(E4o:
4.5
=
sa
boov)
I52> iS
I 8000
I ooo
LOAD
CA1
, 1oo1='
S
S
—
-
34
4 ,0,
EW
2
9
atfecti.ve
TabI€ 319
1
32 s&
ivj
i4
——
&
i5
Otv\
32.
3 3
32 9
14 120
SB
1
133 9
32 S
FL 3oo 292 14 252
53
4Ovst*w,
kor
J
5i4
-..k',
tvoi 2o(a.3o E2
TcP
2
d
53
4
210 %33
140
1
40 2o w...
cover
CGLMaMJTS
LoADS
2.
S4
29o
.
IcAD
COLUM
IMP0cED
aa J
4
-- oof) (u..ctaii LOA o4 M*1P'T$ ifrow. ANALX
It4TRAL CoL-u
3
2o
Co
4
. xr
bpMe.iO.
LoA CASE 2
BS 8110 ref.
1N1RNAL
COLL4Mt.J
Lôd Ca ± Po_,t
(oo* Q' CALCULATIONS
o.d
t
tOO
z.
beo4
M1,
773
i27
-
7.k
O.4M. 04 M - O.(DW\2 = O+0x
£1
tDSIx0.xl3S=
kb')
a
fI4 > 7.
2
( e'y
"T
t)ot.4
7
i
M2 S,
0,
OUTPUT
.4'
2ooo
324
DOS3oO qreLe..s o
(b M+M
—
=
=
33.. t
-
t4 + 544
I.
-
5'8xi0_
3O-4o-i3
=
__
247.
=
L
=
ioox%O
cLa.-,
.4
U23x S44
oe _______ oc4 =
C'
- 0. x .34M =
1v1 0, 0
—
D
bove
a2 od, 1.
4 1c,
2.7 2
M =
Ti
4
> 358
L0.4
oor,
cvv.t
oJ:
•t'255 _____
L76 cN.
_
23.9-7é ______ ____
204 + O- " 51.
RO','SiO
t
k.
2o.4kNr.,
M
3.
CcLrt 9t.2B') 3
42> 29k,
=
-
_______ Mow.€.t
74ik..
L. (-' b")
22
M
=
'2-44
2.3S <
-
fr\
S 3'3 Prt I
k.
O2
-
Ce.ck _____ ,
;5•
Q32O
t- 4T'S (%oi)
N>
K -— _______ = 23-741
cb
oo
O•2S 4Qx.OOx47xlci3 =
Ei 3
si
k.
2''9
-
2.47
658 k. =
x 2'2
a
Mt.
5'8
fr2
4T'25
2.o
i.os(2i
2
>
0/460
c247
(tOGOIvw)
.
28i N
(1 0
9Ow
ok, ok. 19
BS 8110
CALCULATIONS
ref.
(Foo
EXTRJAL COLUMt4
AtAL LoA1 cd
k
IMPO$E.D 2
TOTAL LDAO t.
t
C4E
i
'1
AL
L0A
CLM0MT$
k. loP
'
2.
oTToA4 2 1 2
1
C
i92 i.7
4
4?
rt .
247 25S
eti3e 1!5
SW.
24.
r.o-v 247
c4e
1J2!
4
42
U
i0
S4
S
S
5
SW.
26
15
25
& it il5
25
98
95
t25
l
t.
:
ii
245 2S3 t'25 2S
24e
95 joS
S
13 120
G1
5Th
L5
2&.
7&&
10
U9
25
ii
SW.
4.02
4
ti7
O9x
'
I3\)
0'S Cerc CoAcLo; LK=
E'oO
16O
c
k-S
105
1
1D54
oor)
ectLie
S
L2$
125
V74
--
oS
2a
25B
i1
k2.o
9
SW
EO
Ft (t)LCLA1)
R..ooF)
MME,.iT
CoLuMtt b$1QN
u-AM LOADS
OUTPUT
= =
= 0.9 0.9
2ZI•
Y= Por
usiv.43
0osc.
oac
- oO+44-cY924O
I
U8
300=
boo3) SOT CoLM
Osx
Asu c
top.,
=
1.
N
PrI
CD4Ov
'L15
b
S399
x
(evct
'2.3,
B€.o' 1st.c,+fa4 154,
-
O5S z
fr\
N11hi7xJO
A5=.2o7o2
k,
4.3 237
-k--
oo
- 0•79
(4T' i%D2)
e (.rt
iS 7 k1L
'i
kN.
;
b C
20
S
PSQc
4T2B i90
P%
I(4TEiNAL
COLL..U1M
LLv,k, VertcaS J
F'2
it.rs
ExTR.AL Vt.ai Ltrvk_J
Fl
COLUMN
Se4o,
?
c(1 .
-—;-----—- —----f--
.
:
—
— -
.
4
.
©-4 i
Y9J
I
;4•
coR t,
4
F
c-I
L-,
COV.R
4.
t0k'= 40
;1 — SCALES
-
i: 5O
j
'ZO
Commentary on bar arrangement BS 8110 ref
3.12.5.3
3.12.6.2 3.12.8.15 Table3.27 3.12.7.2 3.12.7.1 3.12.8.12 —
Bar marks
1
2
3
Table 3.27 —
4
3.12.8.13b Table3.27 3.12.8.14
-
—
5
—
6
Notes
The presentation shownabove is schematic. This tabular method adapts readily to element repetition. The sections are shown in their relativepositions 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.
Minimumcrank length = 350 mm (140). Length of short projection beyond crank = compressionlap +. say, 75 mm for tolerance. Reinforcementarea at laps < 10% bh. Bars project above first-floorslab level to provide a compressionlap above the kicker. Bar projection= 35 x 087/095 x 25 mm + 75 mm for kicker= 875 mm, i.e. compressionlap = 800 mm. A single link is provided, since each verticalbar 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. Linksextendto undersideof floor slab. Normally, starter bars are detailed with the footing, as column F2. It can be economic to detail starters withthe columnabove as shown.In this caseit is advisableto schedulethe starter bars so that they can be processedtogetherwiththe footing.Note with this detail that the sectionat mid-height also applies to the starterbar arrangement. The starter bars would be shown dotted on the footing detail together with a suitable cross-reference. Bars project abovethe top of the baseto providea compression lap above the kicker = 35 x 087/095 x 25 + 75 = 875 mm, i.e. lap = 800 mm. As barmark 1, but bars provide a tension lap above 1st floor kicker. Cover = 50 mm. Cleardistancebetween adjacent laps = 100mm<6 x 25 mm; i.e. use factor 1.4 i.e. tension lap = 1125 mm. Projection = 14 x 35 x 087/095 x 25 + 75 = 1195 mm, say 1200mm, Sum ofbar sizes at tension lap = 4 x 25 = 100mm. 100/300x 100 = 33% <40% — OK. This detail provides the maximum lever arm and is the preferred detail for column/beam intersections. Similar to mark 2 links, but extendingto undersideof main beam. Cover to verticalbars = 50 mm. TheseU-bars are provided to restrain the vertical bars in the external face of the column. 21
Foundation reinforcedpad footing
1 ground pressure
600 A A A A A A A
= 200
A
2750
BS 8110 ref.
Tob{e33
4
CALCULATIONS
URAbLITY )Assoi.i U se. ow.sat cover
4o
LOADI.JC
-
De.4
'1 (iet paqe19)
ICxr CIu-ec /,(toi 0kN/v etr ov •. P,.4 r9uw4
.. Acioç,t
.4.4.4
:
•4••4
4
3.i.3.4(')
127/i,4=D
Dtcv. ressu
63x 'i.7S
- c,o-4o-z5
0' 3x 4o,27S0xS52
=
V4f çrç V
V
't
p
Crtt ArwL
.
. 2
= 7.57fw .
B€aror.
=
=
0.017
AC.W4
*.e ore.
1O - 4xoox5S ,Q.rqk.r 4(3oo +3 xS5) ii
cL
=
i
x
bctrs
Q.cKoSs
.
k4
SI
(0.1x0.') 2(75.G) 034. .'( O 7G'20 x 535
3O< 7SOr
scctov., soc
1
0
LI J Jr—
317 O.3
OS '276O = 17
pa
(Q5122)
cka)
2750< 535
22
244Sw
2 f37s-a'so-2xS3S} 1375 12.
27SOcS3S
V
e•
2Jo3kP4w
i5o 's.3S
"
u
.II. .2
I58
t91 :ookM 2 fI3751so%s) 1375 SO'IO'
í.ç
L4.v S\Qr) V
2
3L7.2
3'12U27
40M,l.€r4$
SAR
-
Co4.or
cover
7.
=
o.954xO.9SS35
•• 4(2)
=443
rove4
force V 4n coLa.= 3 113
1's1
5YC2OO -10)
fr\
Co4.or I ,
718
543x 10'
ULTIP.4ATh
Sk
r0t.kN.
No..sd
roFk concete4or4.foa4 s
o6t.v aoçco1uw' Avers c
.
I&.e'1
12.7
2'7S
U.L.S.
'0
roder4e*pesire
ourPuT
SOcrs,eo.cA
1429
.,L
54
C.riK wiftk ok,,
T —
.4
A
_J2O-t- &5OI
PLAN
Mn,.
I
4T25 -2
;
Cover =40
2aB--3oo
COVER.
BI 4O 2\4
-is
A
—
A
Scak, i:SO
Commentary on bar arrangement
It
81 1() ret
3.12.8.1
Bir rnark 1
Table 3.27
3.3.1.4 —
Table 3.27 —
3
1\oles
Straight bars extend full width of base, less end covers. Bars should project a minimum tension bond length beyond the column face = 35 >< 20 = 700 mm < 1150 nim OK. The underside of base is concrete blinded, cover= 40 mm. Column starter bars are wired to bottom mat. Minimumprojection ahose the top of base is a compression lap + kicker = 35 x 087/095 x 25 + 75 = 875 mm. i.e. lap = 800 mm (see p. 21). Links are provided to stahiImie and locatethe starter bars during construction. These are the same site as the column links above. 23
Shear waD
460 ist
-
external plain concrete wall
175
4000 250 14300
900
BS 8110 ref.
CALCULATIONS
OUTPUT
.94.3
¶2> 2
14.
T&bk 33
Ft $TAC )PALtT'( NS ccvr ( svexe. 17 kAI x?ocLsre.
rest&-e
F-y-
()
40w,
LL4
WALL
4o
.
'20 = i.2> t4oLsr
2Ow.wt.
•,
lc.rt stc ck.. ye
C.
49.5k/
O.S(3Z3+8.S)
O.7(24x1E
5Q V3t
C&ct.c c4
GS.1
1t4.kJM
27.8kN/. ;. c4_
a,.r+x4xO.8') WIND
-
O85'<
l42j
T\.21
3)'>Q.
O.5x4234'O
tA
V.RTCA.L Locu.
77/
VSbS22/ec. V: V5S oG,3' 7.7lD3 Oç C (CpQr (k÷c +
LOA1G IEN11'(
coaj.
(U.L,S.
1.4 114.G #
x
B
4<
2
2O
4
e3 eoo.
C
e43
44
/tA4
2o.ik\ ,1
S REAR 4 \5
y3
V
-
ThE
24
Prpke.J ti.:
r
3, 2 .4.
(
rce.
V N
As
:
FOOTIUC
I
pA
oDwt.ck)
resr
2So tLc.k) 01 ccec
cue.dcat# =
I
72E,
cL
= 2oo
lox'2Q.
144L/
=
—
40
4A
7&2
4 '(a-27 S#497 .
+ w4
2I kf3
a
—
14300
;x3f(4.7+4.o)x 14.3 DQ.rt.t vU 0
Mox.
\<
43.4 ' x4.G14-3 13 0./Av 7(
tLte.
3.1'Z.3..1
24
attjoor
oskJ4J
(1.3/)
—
PRovtso
,i2.3.4.2
=
0,tL botLcs
tt3-cx4S
L)L.
ktO
204SkN/M.
x(44+27S447)
3,
j
J
sg Lcc1;')
c
.4
(99 CLf Dt4 2
0<1 k
+4x6 +49.7k4/
P
u:,s4 kWrt
BS
'1
ZS°JQ ;.i_io OKO'
;o ev
ok
(78.SA)
T1O2oo4R, C
u4jc4: €)S
rca4
oo4 1,2.4
ottd".
Tv e co
i
(3-772/1...C)
Commentary on bar arrangement
B 8110 ref
Bar marks
fable 3.27 3.3.1.4 Table 3.25
2
3.9.4.19
3
Notes
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 compressionlap + kicker = 35 x 2 + 75 = 495 mm, say 525 mm, i.e. lap = 450 mm. Undersideof footing is concreteblinded, cover = 4(1 mm. Minimum longitudal reinforcementprovided. 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.
Table 3.27
3.12.3.4 —
4,5,6
7,8 9
Minimum projection above top of first—floor 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 shrinkageand thermal requirements. Bars are placed outside vertical reinfircenient to provide maximum control against shrinkageand thermal cracking. Those bars in the wall 05 in below first—floor slab act also as interna] ties. Tension lap 6)r tie = 35 >< 10 = 350 mm, say 450 mm. Peripheraltie 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
Staircase end-span continuous slab
3500 175
5060
BS 8110 ref.
3?
T.$Ie
•3
o.
4
RLVrt
4
Ave.rMe
ctb L
OUTPUT
ri )
c'-
RE.1STAI4C.
.toor
LoA4 z
CALCULATIONS
c.e.cc o.k...
=
=
cZt.c ce4 SoaA
..
(14GS 1.4.o)5.o
.4'I
TI1AT
2
4FOR.CMeNT
1\
jsL. .i-.ter.or sc.pport. ,
-
0.049
0• 77-Sx 10
SLto.r: V
Dc.-rto
2
3
ck
32.34
CACKK
<2oa.
TE PRov5oP.J
M.
E
w*st d= ToP
04
e t2
Co/ 0TTOM
Tt2. i'.O
C7s4z/p.) = O.31/n
xi
5060 14S
ok
= =
I.
35. '2
-- 340
0k.
1r41 M.
oc, ok,
t-We.ct Ie.r'a T.e.
(s ooc3 co.tttL re4 srase. -
r
.
ox.
bcr5
=
Pre 2T%2 e b-s&L 26
4O 57t
s,cvce. strec.c. 232 a
Mod
AI.twte. a.ry'e. ctejt. ra.o P 3VZIt 27
L2Q
3$. 3Id/M.
cte.t r4o
.3>cO
= T.b\3'tO
=
kN/
4.Okt/
43.
OSx46OxO.Sx'49
r
Q,S
k
0.040
A5
344
k
43.1
eox 44-e.4
C&.€Jc
k/ 4.OkJ3/ .5
.Ms
A5
To.bte.38
.0 05
= = 17.5kN/1k F
T3S 1tivtor SLLr= o.itFL= Q'11x77.5x'O eo r4et O• =
44
2so
- 73
dcvt c. 91
cL4e
o1TOM
4-T2
(4t)
34 Tio-E
Cove.r
FUCHT '5' CCVE
Commentary on
bar arrangement
BS 8110 ref
Bar marks
Notes
Table 3.27
1,5,6
Table 3.25
2,,9
Main tension reinlorcemcnt. Lap lengths and anchorage bond lengths = 35 x 12 = 420 mm, say 450 mm. Similarfor bar marks 12, 13 and 15. Laps arc located to facilitate likely construction sequences. reinforcement. = Minimum area 00013 x 1000x 75 = 228 inniim. Secondary Use 110 (a) 300 = 262 mm/rn.
Fig 3.25
3,4
3.12.10.3.2
7
Table3.25
10,11
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. li—bars provide 50% mid—spanreinforcement 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, say450 mm. Optional ruinfoicLnlent Minimum ULd = 228 mm Simil u for h ii maik 16 27
Column design chart
50 45 40
35 CJ
E E 30
z 25
0
z
20 15 10
5
0
1
23 -
2 44
4 :3
4
5
6
7
8
9
10
11
M/bh 2 —N/mm2
Rectangular columns fcu
40 460
d/h
28
080
12
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 developedby the Reinforced Concrete Council. Versions for both BS 8110and EC2 are in preparation. For detailswrite to the RCC at Century House, Telford Avenue, Crowthorne, Berks RG45 6YS.
Buildability and whole building economics It should be stressedthat the structural solution presented in this publication has been chosenfor the purpose:of illustrating analysis, designand reinforcement detailingprinciples. A typicalbuildingframe accounts for only 10% of the wholeconstruction cost, but affects foundations, cladding and service provision. The choice and details of a building's structure shouldreflect both buildability and overall building economics. Analysis of these factors using a structural optimisation program* or chartsfrom a publication** suggests that a flat slab alternative may save around 2% ofoverall building costs and ten days' construction time. Similarly, rationalisation and simplification ofreinforcement will normally speedconstruction and hence reduce overall construction costs and programmetime. Excessive curtailment and tailoring of reinforcement to save material at theexpenseofrationalisation will provecounter-productive. These aspects are currentlybeing investigated at the EuropeanConcreteBuildingProject at Cardington, and will result in the publication of best practiceguidance. With increasing emphasis on the cost in use ofbuildings, 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 ribbedor coffereci slabs area favoured option to meet daylighting, thermal mass, ventilation and acoustic requirements. *Concept - a computerprogramthatallows the rapid semi-automated choice of concrete frame while considering wholebuildingcosts. Produced by the Reinforced Concrete Council. Available from the RCC on 01344 725733. ** Economic concrete frame elements - a pre-scheme design handbook, basedon BS 8110, that helps designers choose the most viableconcreteoptions. Produced by the Reinforced Concrete Council. Available from the ECA on 01344 7257U4.
IBC
Designed and detailed (BS 8110: 1997)
Cl/SfB (28)
J. B. Higgins and B. R. Rogers
q4
(K)
UDC 624.073.33.012.45:
BRITISH CEMENT ASSOCIATION PUBLICATION 43.501
(Ofl@rete OBC
624.04.001.3
