Is 3370 (Part 2) :2009

n
Iw-w-i W+x

Indian Standard
CONCRETE STRUCTURES FOR STORAGE OF
LIQUIDS — CODE OF PRACTICE
PART 2 REINFORCED CONCRETE STRUCTURES

( First Revision)

I(XI 23.020.01; 91.080.40

0 INS 2009

BUREAU OF INDIAN STANDARDS

MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

June 2009 Price Group 6

Cement and Concrete Sectional Committee, CED 2

FOREWORD
This Indian Standard (Part 2) (First Revision) was adopted by thu Bwxxw of hldhm Standards, after the draft
finalized by the Cement and Concrete Sectional Comnittcc had been [q~provc(iby the Civil Engineering Division
Council.
This standard was first published in 1965. The present revision has been tuken up with a view to keeping obrcast
with the rapid development in the field of construction technology and concrctc design and also to bring further
modifications in the light of experience gained while applying the earlier version of this standard and the amendment
issued.
The design and construction methods in reinforced concrete and prestressed concrete structures for the storage
of liquids are influenced by the prevailing construction practices, the physical properties of the materials and the
climatic condition. To lay down uniform requirements of structures for the storage of liquids giving due
consideration to the above mentioned factors, this standard has been published in four parts, the other parts in the
series are:
(Part 1) :2009 General requirements
(Part 3) :1967 Prestressed concrete structures
(Part 4) :1967 Design tables
While the co~mon methods of design and construction have been covered in this standard, for design of structures
of special forms or in unusual circumstances, special literature may be referred to or in such cases special systems
of design and construction may be permitted on production of satisfactory evidence regarding their adequacy
and safety by analysis or test or by both.
In this standard it has been assumed that the design of liquid retaining structures, whether of plain, reinforced or
prestressed concrete is entrusted to a qualified engineer and that the execution of the work is carried out under the
direction of a qualified and experienced supervisor.
All requirements of IS 456:2000 ‘Code of practice for plain and reinforced concrete (@w-th revision)’ and
IS 1343:1980 ‘Code of practice for prestressed concrete (first revision)’, in so far as they apply, shall be deemed
to form part of this standard except where otherwise laid down in this standard. For a good design and construction
of structure, use of dense concrete, adequate concrete cover, good detailing practices, control of cracking, good
quality assurance measures in line with IS 456 and good construction practices particularly in relation to
construction joints should be ensured.
This revision incorporates a number of important modifications and changes, the most important of them being:
a) Scope has been clarified further by mentioning exclusion of dams, pipes, pipelines, lined structures and
damp-proofing of basements;
b) A new sub-clause on loads has been added under the clause on design;
c) Regarding method of design, it has been specified that one of th~ two alternative methods of design, that
is, limit state design and working stress design may be used; and
d) Provision for crack width calculations due to temperature and moisture and crack width in mature
concrete have been incorporated as Annex A and Annex B, respectively.
The composition of the Committee responsible for formulation of this standard is given in Annex C.
For the purpose of deciding whether a particular requirement of this standard is complied with, the final value,
observed or calculated, expressing the results of a test or analysis, shall be rounded off in accordance with
IS 2:1960 ‘Rules for rounding off numerical values (revised)’. The number of significant places retained in the
rounded off value should be the same as that of the specified value in this standard.
 IS 3370 (Part 2) :2009

Indian Standard
CONCRETE STRUCTUIWS FOR STORAGE OF
LIQUIDS — CODE OF PRACTICE
PART 2 REINFORCED CONCRETE STRUCTURES

( First Revision)
1 SCOPE 3 GENERAL REQUIREMENTS

1.1 This standard (Part 2) lays down the requirements Design and construction of reinforced concrete liquid
applicable specifically to reinforced concrete structures retaining structures shall comply with the requirements
for the storage of liquids, mainly water. These of IS 3370 (Part 1) and IS 456 unless otherwise laid
requirements are in addition to the general requirements down in this standard.
laid down in IS 3370 (Part 1).
4 DESIGN
1.2 This standard does not cover the requirements for
reinforced and prestressed concrete structures for 4.1 General
storage of hot liquids and liquids of low viscosity and Provisions shall be made for conditions of stresses that
high penetrating power like petrol, diesel oil, etc. This may occur in accordance with principles of mechanics,
standard also does not cover dams, pipes, pipelines, recognized methods of design and sound engineering
lined structures and damp-proofing of basements. practice. In particular, adequate consideration shall be
Special problems of shrinkage arising in the storage given to the effects of monolithic construction in the
of non-aqueous liquid and the measures necessary assessment of axial force, bending moment and shear.
where chemical attack is possible are also not dealt
with. The recommendations, however, may generally 4.2 Loads
be applicable to the storage at normal temperatures of All structuresrequired to retain liquids should be designed
aqueous liquids and solutions which httve no for both the full and empty conditions, and the
detrimental action on concrete and steel or where assumptionsregarding the arrangements of loadingshould
sufficient precautions are taken to ensure protection be such as to cause the most critical effects. For load
of concrete and steel from damage due to action of combinations, water load shall be treated as ‘dead load’.
such liquids as in the case of sewage.
Liquid loads should allow for the actual density of the
2 REFERENCES contained liquid and possible transient conditions, for
example, suspended or deposited silt or grit where
The following standards contain provisions, which appropriate. For ultimate limit state conditions and
through reference in this text, constitute provisions of working stress design, liquid levels should be taken to
this standard. At the time of publication, the editions the maximum level the liquid can rise assuming that the
indicated were valid. All standards are subject to liquid outlets are blocked. For serviceability, limit state
revision and parties to agreements based on this conditions, the liquid level should be taken to the working
standard are encouraged to investigate the possibility top liquid level or the overflow level as appropriate to
of applying the most recent editions of the standards working conditions. Allowance should be made for the
indicated below: effects of any adverse soil pressures on the walls,
1S No. Ztle according to the compaction and/or surcharge of the soil
and the condition of the structure during construction
456:2000 Code of practice for plain and
and in service. No relief should be given for beneficial
reinforced concrete (fburth revision)
soil pressure effects on the walls of containment
1786:2008 Specification for high strength bars
structures in the full condition. Loading effects due to
and wires for concrete reinforcement
temperature occurs when thermal expansion of a roof
~ourth revision) forces the walls of an empty structure into the
3370 Concrete structures for the storage of surrounding backfill causing passive soil pressure. This
liquids — Code of practice: effect can be reduced by providing a slidingjoint between
(Part 1): 2009 General requirements @-st revision) the top of the wall and under side of the roof which may
(Part 4): 1967 Design tables be either a temporary free sliding joint that is not cast

1
IS 3370 (Part 2) :2009

into a fixed or pinned connection, or a permanently that in mature concrete shall be calculated as given in
sliding joint of assessed limiting friction. Movement of Annex B.
a roof may occur also where there is substantial variation
4.4.3.1 Crack widths for reinforced concrete members in
in the temperature of the contained liquid. Where a roof
direct tension and flexural tension maybe deemed to be
is rigidly connected to a wall this may lead to additional
satisfactory if steel stress under service conditions does
loading in the wall that should be considered in the
not exceed 115 N/mmz for plain bars and 130 N/mmz
design. Earth covering on reservoir roof’maybe taken as
for high strength deformed bars.
dead load, but due account should be taken of
construction loads from plant and heaped earth which 4.5 Working Stress Design
may exceed the intended design load. 4.5.1 Basis of Design
The junctions between various members (between wall
The design of members shall be based on adequate
and floor) intended to be constructed as rigid should
resistance to cracking and adequate strength.
be designed accordingly and effect of continuity should
Calculation of stresses shall be based on the following
be accouuted in design and detailing of each member.
assumptions:
4.3 Methods of Design a) At any cross-section plane section remains
One of the two alternative methods of design given plane after bending.
in 4.4 and 4.5 for design of water retaining structures b] Both steel and concrete are perfectly elastic and
shall be followed: the modular ratio has the value given in IS 456.
c) In calculation of stresses, for both flexural and
Additional provisions for design of floors, walls and direct tension (or combination of both)
roofs are given in 5,6 and 7 respectively. Structural relating to resistance to cracking, the whole
elements that are not exposed to the liquids or to section of concrete including the cover
moist coriditions shall be designed in accordance together with the reinforcement can be taken
with IS 456. into account provided the tensile stress in
concrete is limited to Table 1.
4.4 Limit State Design
d) In strength calculations the concrete has no
4.4S Limit State Requirements tensile strength.
A1lrelevant limit states shall be considered in the design 4.5.2 Permissible Stresses on Concrete
to ensure an adequate degree ofkafety and serviceability.
4.5.2.1 Resistance to cracking
4.4.1.1 Limit state ofcolla.pse
For calculations relating to the resistance to cracking,
The recommendations given in IS 456 shall be the permissible concrete stresses shall conform to the
followed. values specified in Table 1. Although cracks may
4.4.1.2 Limit states of serviceability develop in practice, compliance with assumption given
in 4.5.1(c) ensures that these cracks are not excessive.
a) Deflection — The limits of deflection shall
be as per IS 456. Table 1 Permissible Concrete Stresses in
b) Cracking — The maximum calculated surface Calculations Relating to Resistance
width of cracks for direct tension and flexure to Cracking
or restrained temperature and moisture effects [Clauses 4.5.1(c), 4.5.2.1 and 6.3(b)]
shall not exceed 0.2 mm with specified cover.
$1 Grade of Permissible Concrete Stresses,
4.4.1.3 Partial safety factors No. Concrete N/mm2

The recommendations given in IS 456 for partial safety Direct Tension Tension Due
factors for serviceability shall be followed. to Bending
(1) (2) (3) (4)
4.4.2 Basis of Design
i) M25 1.3 1.8
Design and detailing of reinforced concrete shall be as ii) M30 1.5 2.0
specified in Section 5 of IS 456 except that 37.L1 of iii) M35 1.6 2.2
IS 456 shall not apply. iv) M40 1.8 2.4
v) M45 2.0 2.6
4.4.3 Crack Widths vi) M50 2.1 2.8
NOTE — The maximum values of shear stress in concrete
Crack widths due to the temperature and moisture shall be as given in IS 456.
effects shall be calculated as given in Annex A and

2
 1S 3378 (Part 2) :2009

4.5.2,2 Strength calculation steel shall be equal to the product of modular ratio of
steel and concrete, and the corresponding permissible
In strength calculations, the permissible concrete
tensile stress in concrete.
stresses shall be in accordance with Table 2 and Table 3.
4.5.3.2 Stwigth calculations
Table 2 Permissible Stresses in Concrete
AllvaluesareinN/rnm2, For strength calculations, the permissible stresses in
steel shall conform to the valu~s specified in Table 4.
N Gradeof Permissible Stressin Permissible
No. Concrete Compression Stress in Bond
(Average) for Table 4 Permissible Stresses in Steel
3 Plain Bars in Reinforcement for Strength
Bending Direct Tension
(J* c= T$(j S1 Type of Stress in Steel Permissible Stresses, N/mm2
(1) (2) (3) (4) (5) ?40. Reinforcement
Plain Round High Strength
i) M25 8.5 6.0 0.9 Mild Steel Bars Deformed Bars
ii) M30 10.0 8.0 1.0
iii) M35 11.5 9.0 1.1 (1) (2) (3) (4)
iv) M40 13.0 10.0 1“2 i) Tensile stress in members 115 130
v) M45 14.5 11.0 1.3
under direct tension,
vi) M50 16.0 12.0 1.4
bendingand shear
NOTES ii) Compressive stress in 125 140
1 The values of permissible shear stress in concrete are given in columns subjected to
Table 3. direct ioad
2 The bond stress given in COI5 shall be increased by 25
percent for bars in compression.
3 In case of deformed bars conforming to IS 1786, the bond 4.5.4 Stresses Due to Moisture or Temperature Chwzges
stresses given above may be increased by 60 percent.
No separate calculation is required for.-.stresses due to
moisture or temperature change in the concrete
Table 3 Permissible Shear Stress in Concrete provided that:
(Clause 4.5.2.2, and Table 2)
a) The reinforcement provided is not less than
N A Permissible Shear Stress in Concrete TC,
No. 100$
N/mm*
that specified in 8,
.-
Grade of Concrete b) The recommendations of the standard with
~-—---- regard to the provision of movement joints
M25 M30 M35 M40 and
Above and f-or a suitable sliding layer beneath the
(1) (2) (3) (4) (5) (6) tank given in IS 3370 (Part 1) are complied
i) <o.~5 0.19 0.20 0.20 oe20 with,
ii) 0.25 0.23 0.23 0.23 0.23 c) The tank is to be used only for the storage of
iii) 0.50 0.31 0.31 0.3 I 0.32
iv) 0.75 0.36 0.3-7 0.37 ~o~g water or aqueous liquids at or near ambient
v) 1.00 0.40 0.41 0.42 0.42 temperature and the concrete never dries out,
vi) 1.25 0.44 0.45 0.45 0.46
and
vii) 1.50 0.46 0.48 0.49 0.49
viii) 1.’?5 0.49 0.50 0.52 0.52 d) Adequate precautions are taken to avoid
ix) 2.00 0.51 0.53 0.54 0.55
x) 2s25 0.53 0.55 0.56 0.5°7
cracking of the concrete during the
xi) 2.50 0.55 0.57 0.58 0.60 construction period and until the tank is put
xii) 2.75 0.56 0.58 0.60 0.62 into use.
xiii) 3.00 and 0.57 0.60 0.62 0.63
above 4S.4.1 Shrinkage stresses may, however, be required
NOTE — A, is that area of longitudinal tension reinforcement to be calculated in specia~ cases, when a shrinkage
which continues at least one effective depth beyond the section
being considered except at supports where the fill area of coefficient of 300 x 10-6may be assumed,
tension reinforcement may be used provided the detailing
conforms to 26.2.2 and 26.2.3 of IS 456. 4.5.4.2 Where reservoirs are protected with an
internal impermeable lining, consideration should
4.5.3 Permissible Stresses in Steel be given to the possibility of concrete eventually,
4.5.3.1 Resistance to cracking drying out, Unless it is established on the basis of
tests or experience that the lining has adequate crack
The tensile stress in the steel will necessarily be limited bridging properties, allowance for the increased
by the requirement that the permissible tensile stress effect of drying shrinkage should be made in the
in the concrete is not exceeded; so the tensile stress in design.

3
IS 3370 (Part 2) :2009

5 FLOORS concrete tanks, the following points should be taken

care ofi
5.1 Provisions of Movement Joints
a) In plane walls, the liquid pressure is resisted
Movement joints shall be provided in accordance with by both vertical and horizontal bending
IS 3370 (Part 1). moments. An estimate of the bending
moments in the vertical and horizontal planes
5.2 Floors of Tanks Resting on Ground
should be made. The horizontal tension
The floors of tanks resting on ground shall be in caused by the direct pull due to water pressure
accordance with IS 3370 (Part 1), on end walls should be added to that resulting
from horizontal bending moment.
5.3 Floors of Tanks Resting on Supports
b) On liquid retaining faces, the tensile stresses
If the tank is supported on walls or other similar due to the combination of direct horizontal
supports, the floor slab shall be designed for bending tension and bending action shall satisfy the
moments due to water load and self weight. The worst following condition:
conditions of loading may not be those given in 22.4.1
of IS 456, since water level extends over all spans in
normal construction except in the case of multi-cell CTti UCIX
tanks, these will have to be determined by the designer where
in each particular case.
Q = calculated direct tensile stress in
5.3.1 When the floor is rigidly connected to the walls concrete,
(as is generally the case) the bending moments at the
Ott = permissible direct tensile stress in
junction between the walls and floor shall be taken
concrete (see Table 1),
into account in the design of floor together with any
direct forces transferred to the floor from the walls or = calculated tensile stress due to
~Cb~~
from the floor to the wall due to the suspension of the bending in concrete, and
floor from the wall. ‘cbt = permissible tensile stress due to
bending in concrete (see Table 1).
6 WALLS
c) At the vertical edges where the waHs of a
6.1 Provision of Joints reservoir are rigidly joined, horizontal
reinforcement and haunch bars should be
6.1.1 Sliding Joints at the Base of the Wall provided to resist the horizontal bending
Where it is desired to allow the walls to expand or moments, even if the walls are designed to
contract separately from the floor, or to prevent withstand the whole load as vertical beams
moments at the base of the wall owing to fixity to the or cantilever without lateral supports.
floor, sliding joints may be employed, In the case of rectangular or polygonal tanks, the side
6.1.1.1 Constructions affecting the spacing of vertical walls act as two way slabs, whereby the wall is
movement joints are discussed in IS 3370 (Part 1). continued or restrained in the horizontal direction, fixed
While the majority of these joints maybe of the partial or hinged at the bottom and hinged or free at the top.
or complete contraction type, sufficient joints of the The walls thus act as thin plates subject to triangular
expansion type should be provided to satisfy the loading and with boundary conditions varying between
requirements of IS 3370 (Part 1). full restraint and free edge. The analysis of moment
and forces may be made on the basis of any recognized
6.2 Pressure on Wails method. However, moment coefficients, for boundary
6.2.1 In liquid retaining structures with fixed or floating conditions of wall panels for some common cases are
covers, the gas pressure developed above liquid surface given in IS 3370 (Part 4) for general guidance.
shall be added to the liquid pressure.
6.4 Walls of Cylindrical Tanks
6.2.2 When the wall of liquid retaining structure is built
While designing walls of cylindrical tanks, the
in ground or has earth embanked against it, the effect
following points should be borne in mind:
of earth pressure shall be taken into account as
discussed in IS 3370 (Part 1). a) Walls of cylindrical tanks are either cast
monolithically with the base or are set in
6.3 Walls of Tanks Rectangular or Polygonal in Plan grooves and keyways (movement joints). In
While designing the walls of rectangular or polygonal either case deformation of the wall under the

4
 IS 3370 (Part 2) :2009

influence of liquid pressure is restricted at the the rest of the tank or by use of the covering of
base. waterproof membrane or by providing slopes to ensure
b) Unless the extent of fixity at the base is adequate drainage.
established by analysis with due consideration
8 DETAILING
to the dimensions of the base slab, the type of
joint between the wall and slab and the type 8.1 Minimum Reinforcement
of soil supporting the base slab, it is advisable
to assume wall to be fully fixed at the base.
8.1.1 The minimum reinforcement in walls, floors and
roofs in each of two directions at right angles, within
Coefficient for ring tension and vertical moments for each surface zone shall not be less than 0.35 percent
different conditions of the walls for some common of the surface zone, cross section as shown in Fig. 1
cases are given in IS 3370 (Part 4) for general and Fig. 2 for high strength deformed bars and not
guidance. less than 0.64 percent for mild steel reinforcement bars.
The minimum reinforcement can be further reduced
7 ROOFS to 0.24 percent for deformed bars and 0.40 percent for
plain round bars for tanks having any dimension not
7.1 Provision of Movement Joints
more than 15 m. In wall slabs less than 200 mm in
To avoid the possibility of sympathetic cracking, it is thickness, the calculated amount of reinforcement may
important to ensure that movement joints in the roof all be placed in one face. For ground slabs less than
correspond with those in walls if roof and walls are 300 mm thick (see Fig. 2) the calc@ated reinforcement
monolithic. If, however, provision is made by means should be placed in one face as near as possible to the
of a sliding joint for movement between the roof and upper surface consistent with the nominal cover. Bar
the wall, correspondence of joints is not important. spacingshouId generally not exceed 300 mm or the
thickness d’ the section, whichever is less.
7.2 Water-Tightness
8.2 Size of Bars, Distance Between Bars, Laps and
In case of tanks intended for the storage of water for Bends — Size of bars, distance between bars, laps and
drinking purposes, the roof must be made water-tight, bends in bars, and fixing of bars shall be in accordance
This may be achieved by limiting the stresses as for with IS 456.

D
l— I

NOTE — For D c 500 mm, assume each reinforcement face controls D/2 depth of concrete.
For D >500 mm assume each reinforcement face controls 250 mm depth of concrete,
ignoring any central core beyond this surface depth.

FIG. 1 SURFACE ZONES: WALLS AND SUSPENDED SLABS

IS 3370 (Part 2) :2009

t
t 13f2
D
UNDER -_._J
3oomn ( NO BOTTOM
1 . , REINFORCEMENT

t
! D/2
D
300mn7 T(3
500mm
. !
1OC)mm
l--
t

1
250mn
I
D
OVER
Nxhm-1

!- m

FIG. 2 SURFACE ZONES: GROUNDED SLABS

ANNEX A
(Foreword, and Clause 4.4.3)
CRACK WIDTH DUE TO TEMPERATURE AND MOISTURE

A-1 CALCULATION OF MINIMUM REIN- Grade of M25 M30 M35 M40 M45 M50
FORCEMENT CRACK SPACING AND CRACK concrete
WIDTHSIN RELATION TO TEMPERATURE ~,, N/mm2 1.15 L3 L45 1.6 1.7 1.8
AND MOISTURE EFFECTS IN THIN SECTION fY- - characteristic strength of the reinforcement.
A-1.1 The design procedures given in A-1.2 to A-1.3 For ground slabs under 200 mm thick the minimum
are appropriate to long continuous wall or floor slabs reinforcement may be assessed on the basis of
of thin cross section. A-2 considers thick sections. thickness of 100 mm and placed wholly in the top
surface with cover not exceeding 50 mm. The top
A-1.2 Minimwn Reinforcement surface zone for ground slab from 200 to 500 mm
To be effective in distributing cracking, the amount of thick may be assessed on half the thickness of the
reinforcement provided needs to be at least as great as slab. For ground slabs over 500 mm thick, consider
that given by the formula: them as ‘thick’ sections with the bottom surface zone
only 100 mm thick.
f(a
PCrh = — .** (1) A-1.3 Cracks can be controlled by choosing the
f Y spacing of movement joint and the amount of
where reinforcement. The three main options are summarized
Pait - critical steel ratio, that is, the minimum ratio, in Table 2 of IS 3370 (Part 1).
of steel area to the gross area of the whole
concrete section, required to distribute the
A=l.4 Crack Spacing
cracking; When sufficient reinforcement is provided to distribute
f Ct = direct tensile strength of the immature cracki~.g the likely maximum spacing of crack S~~X
concrete, which is taken as given below: shall be given by the formula:

6
 IS 3370 (Part 2) :2009

&O where
s=—— ● .* (2)
‘ax A 2p w = coefficient of thermal expansion of mature
where concrete, and
T1 = fall in temperature between the hydratiom
f ratio of the tensile strength of the concrete
peak and ambient.
?=
~b (&) tO tk average bond strength between
concrete and steel, The value of Tl depends on the temperature of
@= size of each reinforcing bar, and concreting, cement content, thickness of the member
steel ratio based on the gross concrete and material for shutters. As guideline, it is
P=
sectiom recommended to use TI = 30”C for concreting in
●

summer and 20°C for concreting during winter, when

For immature concrete, the value of

f
= may be taken
steel shutters are used. For other conditions, the value
fb of 7’]may be appropriately increased.
as unity for plain round bars and 2/3 for deformed bars. In addition to the temperature fall T], there can be a
The above formula may be expressed for design further fall in temperature, 7’..due to seasonal variations.
purposes as: The consequent thermal contractions occur in the mature
concrete for which the factors controlling cracking
behaviour are substantially modified. The ratio of the
● (3)
f
tensile strength of concrete to bond strength, a, is
where fb
n~ = number of bars in width of section, appreciably lower for mature concrete. In addition, the
b width of section; restraint along the base of the member tends to be much
more uniform and less susceptible to stress raisers, since
D= overall depth of member, and
a considerable shear resistance can be developed along
s Max= obtained from lV~aX. the entire length of the construction joint.
The width of a fully developed crack due to drying Although precise data are not available for these effects
shrinkage and ‘heat of hydration’ contraction in lightly- a reasonable estimate may be assumed that the
reinfor&d restrained wills and slabs may be ~bt~ined combined effect of these factors is to reduce the
from: estimated contraction by half. Hence the value of ~MaX
when taking an additional seasonal temperature fall
‘Max = SMax~ ● ** (4)
into account is given by:
where
&= [Ec, + &,e— (loo x 104)] w Max = ~MmX;X(~+~) . . . (6)
L
WM2X = estimated maximum crack width, When movement joints are provided at not more than
~Max = estimated likely maximum crack spacing, 15 m centres, the subsequent temperature fall, Tz9need
c=
Cs estimated shrinkage strain, and not be considered.
E=
te estimated total thermal contraction after A-2 THICK SECTIONS
peak temperature due to heat of hydration.
For ‘thick’ sections, major causes of cracking are the
For immature concrete the effective coefficient of differences which develop between the surface zones
thermal contraction may be taken as one half of the and the core of the section. The thickness of concrete
value for mature concrete (due to the high creep strain which can be considered to be within the ‘surface zone’
in immature concrete). is somewhat arbitrary. However, site observations have
For walls exposed to normal climatic conditions the indicated that the zone thicknesses for D >500 mm in
shrinkage strain less the associated creep strain is Fig. 1 and Fig. 2 are appropriate for thick sections,
generally less than the ultimate concrete tensile-strain and the procedure for calculating thermal crack control
of about 100 x 10-6unless high shrinkage aggregates reinforcement in thick sections is same as that for thin
are used. Hence the value of WMax for cooling to sections.
ambient from the peak hydration temperature may be The maximum temperature rise due to heat of hydration
assumed to be: to be considered should be the average value for the entire
width of section. The temperature rise to be considered
● .* (5) for the core should beat least 10”Chigher than the value
which would be assumed for the entire section.

7
IS 3370 (Part 2) :2009

ANNEX B
(Foreword, and Clause 4.4.3)
CRACK WIDTHS IN lv[ATIJRE CONCRETE

B-1 ASSESSMENT OF CRACK WIDTHS IN

bt(D--x)(a’-x)
FLEXURE &2= ,.. (8)
3E,A, (d-x) ‘
Provided that the strain in the”tension reinforcement is
limited to 0.8~JE~ and the stress in the concrete is For a limiting design surface crack width of 0.1 mm:
limited to 0.45 ~CL,,the design surface crack width
1.5 bt(D–x)(af–x)
should not exceed the appropriate value given in 4.4.1.2
%- —
and may be calculated from equation (7): 3E,~(d-x) ““*‘9)

3acr~m
w . . . (7) q = strain at the level considered,
2(a
1+
-. “- o ‘in
D–x &* = strain due to the stiffening effect of concrete
where between cracks,
b t= width of section at the centroid of the tension
w= design surface crack width,
steel,
aC~ = distance from the point considered to the
D= overall depth of the member,
surface of the nearest longitudinal bar,
E= average strain at the level where the cracking x= depth of the neutral axis,
m
is being considered. To be calculated in E, = modulus of elasticity of reinforcement,
accordance with IL2,
A, = area of tension reinforcement,
c Min = minimum cover to the tension steel,
d effective depth, and
D= overall depth of the members, and
at = distance from the compression face to the
x= depth of neutral axis. point at which the crack width is being
calculated.
B-2 AVERAGE STRAIN IN FLEXURE

The average strain at the level where cracking is being B-4 ASSESSMENT OF CRACK WIDTHS IN
considered, is assessed by calculating the apparent DIRECT TENSION”
strain using characteristic loads and normal elastic Provided that the strain in the reinforcement is limited
theory. Where flexure is predominant but some tension to 0.8 fJE,, the design crack width should not exceed
exists at the section, the depth of the neutral axis should the appropriate value given in 8 of IS 3370 (Part 1)
be adjusted. The calculated apparent strain, &lis then and may be calculated from equation (10):
adjusted to take into account the stiffening effect of
the concrete between cracks &z.The value of the w=3acr&m . . . (lo)
stiffening effect may be assessed from B-3, and where S~ is assessed in accordance with B-5.
sln=&~–q
B-5 AVERAGE STRAIN IN DIRECT TENSION
where
The average strain is assessed by calculating the
&m= average strain at the level where cracking is apparent strain using characteristic loads and normal
being considered,
elastic theory. The calculated apparent strain is then
&, = strain at the level considered, and adjusted to take into account the stiffening effect of
% strain due to stiffening effect of concrete the concrete between cracks. The value of the stiffening
between cracks. effect may be assessed from B-6.

B-3 STIFFENING EFFECT OF CONCRETE IN B-6 STIFFENING EFFECT OF CONCRETE IN

FLEXURE DIRECT TENSION
The stiffening effect of the concrete may be assessed The stiffening effect of the concrete may be assessed
by deducting from the apparent strain a value obtained by deducting from the apparent strain a value obtained
from equations (8) or (9). from equation (11) or ( 12).
For a limiting design surface crack width of 0.2 mm: For a limiting design surface crack width of 0.2 mm:

8
 IS 3370 (Part 2) :2009

2b,D b t= width of the section at the centroid of the

9.. (11) tension steel,
‘= 3E,~
D= overall depth of the member,
For a limiting design surface crack width of 0.1 mm: E, = modulus of elasticity of reinforcement, and
A s = area of tension reinforcement.
bD
t
%= ● . . (12)
E~ The stiffening effect factors should not be interpolated
s
or extrapolated and apply only for the crack widths
% = strain due to stiffening effect,
stated.

ANNEX C
(Foreword)
COMMITTEE COMPOSITION

Cement and Concrete Sectional Committee, CED 2

Organization Representative(s)
Delhi Tourism and Transportation Development Corporation SHRI JOSE KURiAN (Chairman)
Ltd, New Delhi
ACC Ltd, Mumbai SHRI NAVEENCHADHA
SHRI P. SRINIVASAN(Alternate)

Atomic Energy Regulatory Board, Mumbai IX P~ABIR C. BASU

SHiU L. R. 13iSHNOI(Alternate)

Building Materials and Technology Promotion Council, SHRi J. K. PRASA~

New Delhi SHRI C. N. JHA (Alfernate)

Cement Corporation of India Limited, New Delhi SHRI R. R. DESHPANDE

SHRI M. K. AGARWAL(Alternate)

Cement Manufacturers’ Association, Noida SHRi E. N. MURTHY

DR S. P. GHOSH (Alternate)

Central Board of Irrigation and Power, New Delhi MEM~URSECRETARY

DIRECTOR(CIViL) (Alternate)

Central Building Research Institute (CSIR), Roorkee DR B. K. RAO

DR S. K. AGARWAL(Alternate)

Central Public Works Department, New Delhi CHIEF ENGINEER(DESIGN)

ENGINEER(S&S) (Alternate)
SUPERINTENDING

Central Road Research Institute (CSIR), New Delhi DR RAM KUMAR

SHRI SATANDERKUMAR (Alternate)

Central Soil and Materials Research Station, New Delhi SHRI MURARIRATNAM
(Alternate)
SHRI N. CHANDRASEKHRAN

Central Water Commission, New Delhi DIRiXTOR (CMDD) (N&W)

DiWUTYDiRECTOR(CMDD) (NW&S) (Alternate)
Conmat Technologies Pvt Ltd, Kolkata DR A. K. CHAn~RJEE
Construction Industry Development Council, New Delhi SHRi P. R. SWARUP
SHRI RAW JAiN (Alternate)

Delhi Development Authority, New Delhi SHRi A. P. SINGH

SHRI B. B. AIRY (Alternate)

Directorate General of Supplies & Disposals, New Delhi SHRI P. K. LAHIRi

SHRi A. K. M. KASHYAP(Alternate)

Engineers India Limited, New Delhi SHRI ARVINDKUNiAR

SHRI A. K. MISHRA (Alternate)

Fly Ash Unit, Department of Science & Technology, DR VIMALKUMAR

Ministry of Science & Technology, New Delhi SHRI MUKESHMATHUR●
(Alternate)

9
IS 3370 (Part 2) :2009

Organization Representative(s)
Gammon India Limited, Nlumbai SHRI S. A. R~DIX
SHRI V. N. FIE~~ADE(Alternate)

Grasim Industries Limited, Mumbai SHRI A. K. JAIN

SHRI M. C. AGRAW~L(Alternate)

Gujarat Ambuja Cements Limited, Ahmedabad SHRI C. M. DORDI

SHRI B. K. JAGFiTIA(Alternate)

Housing and Urban Development Corporation Limited, CHAIRMANANDMANAGWIGDIRECTOR

New Delhi SHRI V. ARUL KUMAR (Alternate)

Indian Bureau of Mines, Nagpur SHRI S. S. DASi

SHRI MEIiRULHASAN (Alternate)

Indian Concrete Institute, Chennai SI-IRIL. N. APTE

(Alternate)
SHRI D. SRUWVASAN

Indian Institute of Technology, Roorkee PROF V. K. GUPTA

DR BHLJNN~E~SING~ (Alternate)

Indian Roads Congress, New Delhi SECRIiTARYGEIWIRAL

DIRFKTO~(Alternate)

Institute for Research, Development &Training of DR N. RAGHAVINDRA

Construction Trade, Bangalore
Institute for Solid Waste Research & Ecological Balance, DR N, B~ANUMATHIDAS
Visakhapatnam SHRi N. KALItIAS(Ahemate)

Madras Cements Ltd, Chennai SHRI V. JA~ANATHAN

SHRI BALAU K. MOORT~Y(Alternate)

Military Engineer Services, Engineer-in-Chief’s Branch, SHRI J. B. SIiARMA

Army Headquarters, New Delhi SHRI Yomsri SINGHA~[Alternate)

Ministry of Road Transport & Kighways, New Delhi SHRI A. N. DHOIIAPRAR

SHRI S. K. PURI{Alternate)

National Council for Cement and 13ui1dingMaterials, SHRI R. C. WASON

Ballabgarh DR M. M. ALI (Alternate}

National Test House, Kolkata SHRI B. R. M~ENA

SHIUM~TiS. A. ISAUSHIL(Alternate)

Nuclear Power Corporation of India Ltd, Mumbai SHRI U. S. P. VERMA

(Alternate)
SHRI ARVINDSHRIVATAVA

C)CL India Limited, New Delhi DR S. C. AIILIJWALIA

Public Works Department, Government of Maharashtra, Mumbai FWPRESENTXTXVE

Public Works Department, Government of Tamil Nadu, Chennai SUPERINTENDING

ENGINEER(DEM~N)
EXEWTIVEENGINIiER(Alternafe)

Research, Design & Standards Organization (Ministry of Railways), SHRI R. M. SHARMA

Lucknow SHRi V. K. YADAVA(Alfernate)
Sanghi Industries Limited, Sanghi Nagar, Ranga Reddy District SI-iRi D. B. N. RAO
DR I-I. K. PAIWAIK(A1/erna@)

Sardar Sarovar Narmada Nigam Limited, Dist Narmada CHIIIF 13NGINIiIiR

(NAVGAMDAM)
SUPERINTENDING ENGINEER(Alternate)

Structural Engineering Research Centre (CMR), Chermai SHRI A. CH~LLAPPAN

SHRI J. PRABHAKAR(Al~emate)

The India Cements Limited, Chennai SHRI S. GOMNATH

SHRI R. ARUNA~ALAM(Alternate)

The Indian Hume Pipe Company Limited, Mumbai SHRI P. D. KIHXAR

SHRI S. J. SHAH (Alternate)

The Institution of Engineers (India), Kolkata Ek FL C. VISV~SVA~AYA

SHRi 13ALBHiSI~~H (Alternate)

Ultra Tech Cement Ltd, Mumbai Si+RI SUBRATOCHOW~HURY

SI-IRIBIsw~nT DHAR (Alternate)

10
 Is 3370 (Part 2) :2009

Organization Representative(s)
Voluntary organization in Interest of Consumer Ed~cation, SHRI HEMANTKIJMAR
New Delhi

BIS Directorate General SHRIA. K. SAINL Scientist ‘F’& Head (Civ Engg)
[Representing Director General (Ex-o~cio)]

Member Secretaries
SW SAN~A~P~PJ~
Scientist ‘E’ &Director (Civ Engg), BIS
SHIU S. AIWN KUMAR
Scientist ‘B’ (Civ Engg), BIS

Concrete Subcommittee, CED 2:2

Delhi Tourism & Transportation Development Corporation SHRI JOSIZKURIAN(Convener)

Ltd, New Delhi
ACC Ltd. Mumbai SHRI ANI~ BANCHHO~
(A[ternafe)
SHRI P. BANDOPADHYAY

Atomic Energy Regulatory Board, Mumbai DR PRAIURC. BASW

SHRI L. R. BISHNQI(Alferna?e)

Building Materials and Technology Promotion Council, S~RI J. K. PRASA~

New Delhi SHRI PANKAJGUPTA(Alternate)

Central Building Research Institute (CSIRJ Roorkee DR B. K. RAO

DR S. K. AGARWAL(Alternate)

Central Public Works Department, New Delhi SUPERINTENDING

ENGINEER(DESIGN)
EXECUTIVE (DESIGN)(Ahemate)
EN~INIZER

Central Road Research Institute (CSIR), New Delhi DR RENU MATIiUR

SEIRISATAN~ERKWMAR(Alternate)

Central Soil & Materials Research Station, New Delhi SHRt MURARIRATNAM
(Alternate)
SHRIN. CHAN~RASIiKH;~RAN

Central Water Commission, New Delhi DIRIX~OR(C&MDD)

1XPUT%DIRK.TOR(C&MDD) (Alternate)
Engineers India Limited, New Delhi SHRI AIWINtI KUMAR
SHRi T. BALRAJ(Alternate)

Fly Ash Unit, Department of Science and Technology, DR VINIALKUM~R

Ministry of Science & Technology, New Delhi SHRI MUKESHMATHUR(Alternate)

Gammon India Limited, Murnbai SHRI S. A. REDIII

DR N. K. NAYA~ (Alternate)

Grasim Industries Ltd, Mumbai SHRI A. K. JAIN

SHRI M. C. AGRAWAL(Alternate)

Gujarat Ambuja Cement Limited, Ahmedabad SHRI C. M. ~ORDI

SHRI B. K. JAG~A (Alternate)

Indian Concrete Institute, Chenrmi PROF M. S. SHEI-TY

SHRI L. N. APTE (Alternate)

Indian Institute of Technology, New Delhi DR B. BHATTACHARJEE

Indian institute of Technology, Kanpur DR SUDHIRMISHRA

Indian Institute of Technology, Roorkee DR ASHOK KUMARJAIN

Larsen and Toubro Limited, Chennai DR B. SWARAMASARMA

SHRI KINGSLEYJ. D. ERNEST.(A2ternate)

Military Engineer Services, Engineer-in-Chief’s Branch, BRIG R. K. GUPTA

Army Headquarters, New Delhi COL V. K. BA~GLA (A2tema/e)

11
IS 3370 (Part 2) :2009

Organization Representative(s)
Ministry of Road Transport and Highways, New Delhi SHR1T, B. B~N~RJEE
SHRI KAMLESHKUMAR(Alternate)

National Buildings Construction Corporation Limited, SHRr L. P. SINGH

New Delhi SHRI DARSHANSINGH (Alternate)

National Council for Cement & Building Materials, SHRI R. C. WASON

Ballabgarh SHRI H. K. JULKA (Alternate)

National Institute of Technology, Warangal DR C. B. KAMESWARARAO

DR D. RAMA SIXHU (Alterna~e)

Nuclear Power Corporation of India Limited, Mumbai SHRI U. S. P. VERMA

(Alternate)
SHRI ARVINDSHRIVATAVA

Pidilite Industries Limited, lvlumbai SHRr P. L. PATRY

SW K. PA~MAKAR(Alternate)

Ready Mixed Concrete Manufacturers’ Association, Bangalore SI-IRIViJAYKUMARR. KULKARN1

Research, Design & Standards Organization (Ministry of Railways), JOINTIXRECTORS~AN~ARDS(B&S)/CB-l

Lucknow JOINTDIRECTORSTANDARDS(B&S)/CB-11 (Alternate)
Structural Engineering Research Centre (CSIR), Chennai SHRI T. S. KRISHNAMOORTIW
SHRI K. BALASUBRAMANIAN(Alternate)
Tandon Consultants Private Limited, New Delhi SHRI MAHFiSI-iTANDON
SHRI VINAYGUPTA(Alfernate)

TCE Consulting Engineers Limited, Mumbai SHRI J. P. HA~AFi

SI-IRIS. M. PALtIKA~(Aherna?e)

Torstee! Research Foundation in India, New Delhi DR P. C, CHOWDHURY

DR C. S. VISHWANATHA
(Alterna~e)
In personal capacity (35, Park Avenue, Annamma, DR C. RAJKUMAR
Naicker Street, Kuniamuthur, Coinabatore)
In personal capacity (36, Old Sneh Naga~ Wardha Road, ~RI LALI~ KUMARJAIN
Nagpur)

Panel for Revision of IS 3370 (Parts 1 and 2), CED 2: 2/Pi

National Council for Cement and Building Material, DR ANIL KUMAR (Convener before 18 October 2006)
13allabgarh
In personal capacity (36, Old Sneh Nagac Wardha Road, SHRI LALITKUMARJAIN (Convener since 18 October 2006)
iVagpur)
Central Road Research Institute (CSIR), New Delhi DIRECTOR
SHRI SATANDERKUNIAR(Alternate)

Delhi Tourism and Transportation Development Corporation SHRI JOSE KURIAN

Ltd, New DeIhi
Gammon India Ltd, Mumbai SHRI S. A. REDDI

Indian Institute of Technology, New Delhi DR S. N. SINFiA

Indian Institute of Technology, Roorkee DR AsHo~ K. JAIN

Military Engineer Services, Engineer-in-Chief’s Branch, SHRI J. B. SHARMA

Army Headquarters, New Delhi S~RI YO~ESI-IK. SINGHAL(Alternate)

National Council for Cement and Building Material, SHRI H. K. JULKA

Ballabgarh SHRI R. C. WASON (Alternate)

School of Planning and Architecture, New Delhi DR V. THIRUVENGAIIAM

Structural Engineering Research Centre (CSIR), Chennai SHRI T. S. KRISH~AMOORTHY

SHRI K. BALASUBRAMANIAN(A/ternate)
TCE Consulting Engineers Limited, Mumbai SHRI S. M. PALIiKAR
SHRI S. KRISHNA(Alternate)

In personal capacity (K-J!/2, Kavi Nagac Ghaziabad) DR A. IL MIITAL

GMGIPN-140 Rls/fw/09-3oo
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