EXPANSION JOINT TREATMENT: MATERIAL & TECHNIQUES

Conference on: “Trends and Challenges of Civil Engineering in Today’s Transforming World”
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29th March, 2014, Civil Engineering Department S.N.P.I.T. & R.C., Umrakh
EXPANSION JOINT TREATMENT: MATERIAL &
TECHNIQUES
Farhana M. Saiyed 1
, Ashish H. Makwana2
, Jayeshkumar Pitroda3
, Chetna M. Vyas4
Final Year Student, BE Civil Engineering, BVM Engineering College, Vallabh Vidyanagar, Gujarat, India 1
Final Year Student, ME C E & M., BVM Engineering College, Vallabh Vidyanagar, Gujarat, India 2
Assistant professor, Civil Engineering Dept., BVM Engineering College, Vallabh Vidyanagar, Gujarat, India 3
Assistant professor, Civil Engineering Dept., A.D. Patel Institute of Technology, New Vallabh Vidyanagar,
Gujarat, India 4
Abstract: Although buildings are often constructed using flexible materials, roof and
structural expansion joints are required when plan dimensions are large. It is not possible to
state exact requirements relative to distances between expansion joints because of the many
variables involved, such as ambient temperatures during construction and the expected
temperature range during the life of a building. Expansion joints are periodic breaks in the
structure of the buildings. An expansion joint is a gap in the building structure provided by
an architect or engineer to allow for the movement of the building due to temperature
changes. An expansion joint is an assembly designed to safely absorb the heat-induced
expansion and contraction of various construction materials. They are commonly found
between sections of slabs, bridges, and other structures. The “assembly” can be as simple as
a caulked separation between two sections of the same materials. More recently, expansion
joints have been included in the design of, or added to existing, brick exterior walls for
similar purposes. In concrete and concrete block construction, the term applied is “control
joint,” but serves similar purposes. Throughout the year, building faces and concrete slabs
will expand and contract due to the warming and cooling of our planet through the seasons.
The structures would crack under the stress of thermal expansion and contraction if
expansion joint gaps were not built into the structures. Even today the expansion joint gaps
are often neglected during the design process, and simple caulking is used to fill these gaps
to complete a project. This simple caulking cannot handle the thermal expansion due to the
changing seasons, ultimately leaving a leak point in the structure. This expansion joint
becomes the main source of leakages in the structure which can ruin the interiors of the
building if not sealed or treated confidently. Waterproofing these joints often an overlooked
aspect of waterproofing design and detailing.
Keywords: Building, Expansion joints, Material, Techniques

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I. INTRODUCTION
A. Defination
The term “expansion joint” as used refers to the isolation joints provided within a Building
to permit the separate segments of the structural frame to expand and contract in response to
Temperature changes without adversely affecting the building's structural integrity or
serviceability.
B. Overview of Expansion Joint
The word „joint‟ is used in building parlance to cover elements which have to perform
quite different functions, e.g. beam-column joints and isolation joints. In the former the joint
has to provide continuity of structural action between the members meeting at the joint. In the
latter the joint has to ensure separation between the adjacent members to allow one member
to move independently of the other.
C. The four basic reasons for requiring joints
 The member or structure cannot be constructed as a monolithic unit in one placement of
concrete.
 The member has to be of limited size so it can be handled by cranes, etc.
 The structure or member on one side of the joint needs to be able to move relative to that
on the other.
 The design assumptions for the structure or building need the joint at that point, so the
analysis is simplified.
II. TYPES OF JOINTS IN CONCRETE
i) Construction Joints ii) Isolation Joints

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iii) Contraction Joints iv) Expansion Joints
Figure 1: Types of Joints in Concrete
Source: http://www.expertsmind.com & http://www.pavement.com
III. EXPANSION JOINT
A. Details of expansion joint
The normal practice in runways, bridges, buildings and road construction is to provide
expansion joints between cutting slabs of reinforced concrete at designing intervals and at
intersections with other constructions. These joint filers are then covered with sealing
compounds.
Concrete expands slightly when the temperature rises. Similarly, concrete shrinks upon
drying and expands upon subsequent wetting. Provision must cater for the volume change by
way of joint to relieve the stresses produced. An Expansion joint is actually a gap, which
allows space for a building to move in and out of. The movement of the building is caused
most frequently by temperature changes, the amount of expansion and contraction of building
depends upon the type of material it is constructed out of. A steel framed building will move
by a different amount then a concrete framed one. In case of a small building, the magnitude
of expansion is less and therefore, no joint is required either in the floor or roof slab. But in
case of the long building, the expansion is very large and may be as much as 25 mm.
Therefore, buildings longer than 30 m are generally provided with one or more expansion
joints.
Having successful determination the predicted movement along the three principal axis
of the Expansion joint gap, the designer and Specifier are now faced with a more critical
choice, that of choosing of material to seal the joint gap itself from the element. This is a
particular important building envelope design consideration, especially when moisture and
water are present.

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Figure 2: Expansion Joint
Source: https://www.google.co.in/#q=EXPANSION+JOINT+++++images
Figure 3: Movement at an Expansion Joint
Source: https://www.google.co.in/#q=movement+at+an+expansion+joints+images
B. Problems due to Expansion Joint
The main problems of expansion joints are –
But the side effects developed by the water leakage and pest attack are very dangerous
and tedious
Leakage of Water Pest attack Poor workmanship

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1) The problem caused by water leakage:
 In rainy season water travels from the expansion joints and goes into the walls which
creates discomfort for people
 Also the paints of the walls are affected by weather.
 The steel members get corroded and results in to risk of structural failure.
 The electric lines in expansion joints can be short circuited.
2) Problems due to pest attack:
 The pest attack on the wooden pads or the Shalitex board of expansion joints and also
travels from electric pipes and spreads in the whole structure.
3) Problems due to poor workmanship:
 The expansion joints provided only on the superstructure can cause failure of foundation.
 The expansion joints not provided on the parapet walls can result into uneven cracks on
parapet walls.
C. Need of Expansion Joints
 If not provided the structure shall be subjected to internal compressive stresses and these
stresses may be so high that structure may fail.
 The amount of expansion as already stated depends upon the extent of change of
temperature, the extent of the structure, and on the coefficient of linear expansion of the
material.
 But of these three parameters changes in temperature and coefficient of linear expansion
cannot be controlled.
 It is only the extent of the structure which can be reduced to limit the expansion the
structure within specified limits.
 Based on these concepts it is seen that the structure 30 meters long when subjected to
temperature change of 50 degrees F expands about 10 mm.
 Small buildings usually do not require any expansion joint, but if the continuous length
of the structure exceeds 45 meters expansion joint should be provided.

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D. Factors affecting on Expansion Joints
E. Location of Expansion Joints
 Change in Materials: Wood to Steel, Concrete to Steel, flexible to rigid
 Material direction change: Steel deck flutes
 Building shapes: T, H, O, X, Y, C and others
 Building size, typically greater than 30m in any direction, can be larger or smaller areas
 Additions, regardless of shape or size
 Equipment isolation, Atriums, Skylights
 Non load bearing walls or in some cases load bearing
Thermal
•The different materials in buildings expands and contracts
according to their different co-efficient of expansion related to
temperature change so stresses devolved in such conditional can
be minimized by expansion Joints.
Wind
•The stresses developed in storms and hurricanes can be
minimize.
Loads
•Bending moments due to load snow, rain, vibrations, can be
decreased by expansion joints.
Earth quake
•The thrust on the building can be decreased by expansion joints
during earthquake.

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Figure 4: Location of Expansion Joints
Source: https://www.google.co.in/#q=Location+of+Expansion+Joints+images
F. Construction of Expansion Joint
The expansion joint is to be provided from the foundation to the top floor of the building.
The one side of the expansion joint is first constructed to desired level, then the Fiberboard is
placed where Expansion joint is to be provided then the other side is constructed. The
fiberboard is sealed with sealing compounds. Thus the whole construction of the building is
done.
G. Material & Techniques
The gap of expansion joints is never left open. It is filled with a compressible material so
as to make it water tight. The following materials are required to render the expansion joint
watertight.
1) Joint filler: Bitumen, bitumen containing cellular materials, cork strips, rubber, mineral
fiber, expanded plastic, pith, coconut, etc. are the usual joint filler materials. Joint filler
should be compressible material tightly fitted in the gap. Being compressible, they
Joint filler Sealing compound Water bars

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readily allow free expansion of adjacent parts. It should regain 75% of its original
thickness when external pressure is removed from it. They should be rigid, durable and
resistant to decay.
2) Sealing compound: its function is to seal the joint against passage of moisture and to
prevent the ingress of dust, grit or other foreign matter into the joint. It should be tint
less, non-toxic, insoluble and readily workable. Mastic or Hot-applied bituminous
sealing compound is mostly used for the purpose.
3) Water bars: the function bars are to seal the joints against passage of water. Water bars
may be made of rubber, P.V.C., G.I. sheet, copper, or aluminum sheets. G.I. Water bar
should not be used under corrosive conditions. Width of water bar may be varied from
the 15cm. to 20cm.and thickness should not be less than 0.56 mm. they are given U or V
fold to allow expansion and contraction at the joints.
H. Installation of Expansion joint
Expansion joint installation is a specialty, and project documents should emphasize the
need for a heightened care required to complete the task. The contract documents should
require that the contractor call a pre-construction meeting of parties involved in performing
the work at and around the expansion joints, to educate all involved parties about their
responsibilities in installing the expansion joints and ensure that the following conditions are
met:
1) The expansion joints in the floor should be straight and should align, without offset, with
expansion joints in vertical planes such as double columns and walls.
2) The expansion joint separation should not be used as a place for tolerance build-up from
other construction activities.
3) The expansion joint gap should have a consistent width throughout. If the gap is cast at a
temperature other than the specified mean temperature, and/or post-tensioned concrete is
used, the adjustment in the gap width may be needed to ensure that the specified joint has
the specified movement capability. A design example published in the 2009 PTI Journal
illustrates the design steps needed.
4) Forms should be strong with tight joints so as to allow concrete next to the forms to be
thoroughly vibrated to ensure proper consolidation, to prevent seepage of concrete and
irregularities in joint shape, and to avoid voids within concrete or on concrete surface.
5) The forms should be removed promptly after initial curing of concrete to prevent them
from being squeezed or becoming dislodged due to the joint movement.

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6) Once formed, the expansion joint gaps in the decks and floors need to be protected from
damage by construction traffic throughout their length. At crossing points, joints should
be protected with plates or ramps.
7) Joints in the walls should be free of mortar protrusion, masonry ties, protruding shelf
angles, and other obstructions that might hinder the movement or obstruct installation of
the expansion joint system.
TABLE I: - C/C SPACING OF EXPANSION JOINT IN VARIOUS ELEMENTS
Sr.
No.
Description of elements c/c spacing Reference
1. Walls
i) Load bearing walls one brick
and more in thickness and having
cross-walls at intervals.
30 m
IS 3414-1968: The
spacing of expansion
joints in various elements
of the structure
ii) Load bearing walls without any
cross-walls
30 m
If wall acts as panel walls
between columns spaced not
more than 9 m c/c no joints are
required. Control joints may be
given over the center of openings
at half the spacing of expansion
joint.
2. Roofs
i) Ordinary roof slabs of RCC on
unframed construction protected
by mud phuska.
20 m to 30 m interval and at all
changes of direction points of
structure.
ii) Thin unprotected RCC slabs. 15 m
3. Chhajjas, balconies and parapets.
Copings
6 to 12 m.
Corresponding to joints in the
roof slabs.
4. Framed structures At 30 m intervals and at corners
or change of direction points.
IV.CASE STUDY
A. Site Visit
As we visited the some sites of untreated or poorly constructed expansion joints, we
encountered very major problems in maintaining, installing and treating expansion joints.
i) A part of a whole expansion joint is treated
which is not very durable and not much care
is taken off in treating.
ii) The gap for movement of overlapped slab
is not provided as a result the cracks are
formed in the cover.

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iii) In this picture the joint and the treatment
are at different places.
iv) Here the Shalitex board is not properly
installed so water can penetrate from
cavities.
v) In this joint pest has completely
demolished the Fiberboard as it is not
covered to resist this sort of problem and
weather effects.
vi) A typical failure at an expansion joint
junction.
B. Treatment methods for expansion joints in various elements
1) Walls: The joints in the wall are not left exposed. They are covered with covering sheets
which may be of aluminum, hard board, AC sheet or timber plank. Normally A.C. sheet
is used to cover the joint. The covering sheet is fixed to the wall on one side of the joint
with screws and on the other side by screws through oval shaped slots. The oval slots
permit movement at the joint without causing any damage to the covering sheet.
Expansion joint in the roof shall invariably be provided with joint filler and water bar.
Joint in floor shall be invariably sealed to prevent accumulation of dirt, dust, therein.
The joints in the wall are not left exposed. They are covered with covering sheets
which may be of aluminum, hard board, AC sheet or timber plank. Normally A.C. sheet
is used to cover the joint. The covering sheet is fixed to the wall on one side of the joint
with screws and on the other side by screws through oval shaped slots. The oval slots
permit movement at the joint without causing any damage to the covering sheet.
Expansion joint in the roof shall invariably be provided with joint filler and water bar.
Joint in floor shall be invariably sealed to prevent accumulation of dirt, dust, therein.

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Figure 5: Expansion Joint treatment in walls
Source: https://www.google.co.in/#q=Material+%26+Techniques+of+Expansion+Joints+images
2) Framed Walls: In case of framed structure, it is necessary to provide two frames, one on
either side of the expansion joint. The treatment of joints is similar to those given to the
masonry wall expansion joint.
Figure 6: Expansion Joint treatment in Framed walls
3) Roofing Slab: The gap of the joint should be sealed with a water bar and sealing
compound. In order to prevent cracks in the masonry above or below the expansion joint
R.C.C or plain concrete bed blocks should be provided in the masonry below the
expansion joint in the slab.
Figure 7: Expansion Joint treatment in Roofing Slab

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C. Some new methods used for treatment of Expansion joint in present time
1) In this method a combination of fiber tape and adhesive material is used to cover the
expansion joint.
i) In newly constructed building or in treatment of
expansion joint in existing building the cleaning of
expansion joint is required in the first step.
ii) Now the adhesive materials are properly
mixed.
iii) Now water is applied on the surface where the
adhesive is to be placed so moisture in chemicals is
not absorbed by the surface.
Then the first layer of adhesive chemicals is coated.
iv) The fiber tape is instantly placed over the
coating so it can properly cure.
v) The second coat is done over the tape. After the half an hour curing the 3rd
coating of adhesive chemical is
introduced. When flooring is done 15 mm gap is left on treated joint. The provided gap is then filled up with
silicon gel.

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2) Treatment by simple slab construction
Figure 8: Treatment by simple slab construction
Source: https://www.google.co.in/#q=Expansion+joint+Treatment+by+simple+slab+construction+images
 As shown in figure the overhanging slab is constructed on the expansion joint.
3) Treatment using rubber gasket and aluminium sheet:
Figure 9: Treatment using rubber gasket and aluminium sheet
Source: https://www.google.co.in/#q=treatment+using+rubber+gasket+and+aluminium+sheet+images
V. CONCLUSION
 It is important that at the design stage the designer recognises the factors that may affect
a building‟s performance and makes provisions to accommodate any likely movement.
 Adequate provision shall be made for expansion and contraction appropriate to the
service conditions of the structure.
 New methods used with latest materials are more advantageous and provides faster
workmanship as well as long life to expansion joint with water tight provision.

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REFERENCES
[1] JAMES. M. FISHER S.E, Steel conference, expansion joints, where, when and how?
[2] Expansion Joints in Buildings: Technical Report No. 65, http://www.nap.edu/catalog/9801.html
[3] Mohammad Iqbal, D. Sc., P.E., S.E., Esq. October, 2010
[4] Structural Design - Discussions on design issues for structural engineers… Joint Publication of NCSEA |
CASE | SEI
[5] Kris zielonka P.eng. Technical manager situra INC., A study of Practices in design, detailing and water
proofing, expansion joint in North America.
[6] Technical note 63, joints in concrete buildings, sept 2004.
[7] Gurcharan Singh, Building construction and materials, standard book house, 12th edition 2012
[8] http://www.expertsmind.com
[9] http://www.pavement.com
[10] http://www.stpltd.com/html/Presentation/Sealants%20and%20Additives/ShaliSeal%20PS%20PG.pdf
[11] http://www.heidelbergcement.com/uk/en/hanson/products/blocks/technical_information/thermalite_move
ment_control.htm
[12] http://besser.tsoa.nyu.edu/impact/f95/Cdwa/MATERIAL.HTML
[13] http://www.nbmcw.com/articles/waterproofing-construction-chemicals/3202-treating-expansion-joints-
with-koster-joint-tape-system.html
[14] https://www.google.co.in/?gws_rd=cr&ei=llT3UpPSEoyCrgemnYHwDA#q=Wind+effect+on+buildings+i
mages
[15] https://www.google.co.in/?gws_rd=cr&ei=llT3UpPSEoyCrgemnYHwDA#q=Thermal+effect+on+building
s+images
[16] https://www.google.co.in/?gws_rd=cr&ei=llT3UpPSEoyCrgemnYHwDA#q=Loads+effect+on+buildings+
images
[17] https://www.google.co.in/?gws_rd=cr&ei=llT3UpPSEoyCrgemnYHwDA#q=Earth+quake++effect+on+bu
ildings+images
[18] https://www.google.co.in/?gws_rd=cr&ei=llT3UpPSEoyCrgemnYHwDA#q=Problems+due+to+Expansio
n+Joint+images

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