Guidelines Concerning Expansion Joint Selection And Design

Product description

An expansion joint (dilation joint, from Latin dilatare: to expand, to extend) is a purposefully created slit in a building or structure, the task of which is to allow individual components of the structure to work independently of the rest. Separate components transfer loads, deformations and movements by themselves. Expansion joints are executed to protect the structure from:
- concrete contraction and temperature differences that can cause cracks or fractures of a reinforced steel structure,
- unequal setting
- concrete creep.

The following types of expansion joints are known:

  • structural joints - they separate a part of the building forming one complete whole with respect to statics, manufacture technology and foreseen site use, or stem from its grand proportions. They are used if a foundation method is changed, a building's structural arrangement is changed or load differences are great. They separate all structural components across one section, from the foundation to the roof,
  • thermal expansion joints - they work to contract or expand and protect the building against cracks arisen as a result of temperature changes. They act to eliminate the influence of large stresses from thermal deformations of individual building components,
  • anti-vibration expansion joints - in most cases associated with industrial structures, where they are supposed to protect the site or its constituent components against the influence of vibrations (dynamic and/or acoustic influences) from foundations and the framework profiles on which machines are placed. Similar properties and a similar requirement of use for a structure may be imposed by virtue of a building's location in the area of influence of seismic waves caused by earthquakes or mining damage,
  • expansion joints allowing unequal structure setting - the phenomenon of setting stems from mechanical properties of soil, and in particular, from its compression ability, or the ability to reduce its volume under the influence of load. If the soil conditions change under the foundations, within the outline of the building's silhouette, then its subdivision into individually working parts is substantiated from the economic point of view. One needs to remember that expansion joints should be designed in buildings along their entire height, from the foundation to the roof.


A national annex to Polish standard PN-EN 1992-1-1 indicates the maximum distances between expansion joints.

Table no. NA.1
Structure type Distance between expansion joints djont
in metres
Structures subject to outside temperature variations
a) non-reinforced walls
b) reinforced walls
c) reinforced concrete framework structures
d) uninsulated roofs, cornices

5
20
30
20
Heated, multi-storey buildings
a) internal walls and ceilings, concreted monolithically in one line
as above - concreted in sections not exceeding 15 m in length, 
with spaces left over for later concreting
c) internal pre-cast walls with external pre-cast walls
d) as above - with external walls of aerated concrete
e) as above - with light outside walls, lengthwise part providing rigidity in the central part of the building
f) as above - with fixing walls in the end parts of the building
g) pre-cast framework structures and monolithic structures with reinforcement in the central part of the building
h) monolithic framework structures with walls providing rigidity in the end parts - as appropriate

30
as in the case of internal pre-cast walls
50
40
70
50
as in the case of internal pre-cast walls
as for a) or b))
Heated single-storey reinforced concrete walls without walls providing rigidity or only in central part, with outside walls of low rigidity not experiencing cracking in case of deformations in their plane - depending on structure height h
a)  h≤5m
b)  5 c)  h  ≥  8  m


60
10 + 10h
90
Massive walls, if no special processes are used to reduce hardening heat and contractions depending on thickness
a) b = 0,3 m ÷ 0,6 m
b) 0,6 m < b ≤ 1,0 m
c) 1,0 m < b ≤ 1,5 m
d) 1,5m < b ≤ 2,0m

 

Possible directions of movement of building parts connected through expansion joints

Construction objects and their individual components are always subjected to influences by various forces that are the result of setting, temperature variations, static and dynamic loads. These forces cause changes in the tension in the components, which can lead to the emergence of irreversible changes in the parts or contribute to cracking, and in the extreme, to fractures.
In order to reduce as much as possible the probability of emergence of permanent damage or them spreading to other parts of the structure, independent parts of the building are allowed individual static work. This requirement is fulfilled by designed structure separations - expansion joints.
In certain structures or their parts, an additional requirement for expansion slit protection is their water-tightness. This applies in most cases to spaces susceptible to permanent contact with water or other fluids, swimming pools, multi-storey parking lots, ramps or pedestrian overpasses. Assurance of water-tightness requires particular precision and attention to detail during the installation of protective components. Important is also the knowledge of transport vehicles that will be used in that space, and the types of tyres they will use.

Static tests were conducted for all floor profiles, according to load data for forklift trucks per norm PN-EN 1991-1-1 and DIN 1072 - loads from vehicle traffic.

 

Below the tables, norm loads are indicated, to which a profile may be subjected, and according to which it is chosen.

Deflex floor profile load table
Load type According to norm 
Vehicle type Maximum static vertical load from vehicle axle
[kN]
Area of tyre adherence to surface [cm]
Separation between components anchoring the profile to the grounda [cm]
Distance from last anchor to profile end [cm]

PN-EN 1991-1-1
DIN 1055






Forklift truck
26
20/20 30
15

PN-EN 1991-1-1
DIN 1055
40
20/20 30
15

PN-EN 1991-1-1
DIN 1055
63
20/20 30
15

PN-EN 1991-1-1
DIN 1055
90
20/20
30
15

PN-EN 1991-1-1
DIN 1055
140
20/20 30
15

PN-EN 1991-1-1
DIN 1055
170
20/20 30
15

DIN 1072


Goods truck
40
20/30
30
15

DIN 1072
30
20/26
30
15

DIN 1072
20
20/20
30
15

DIN 1072
50
20/40
30
15

DIN 1072
100
20/60
30
15

particular situation Pallet lifter 10
2/3
30
15

PN-EN 1991-1-1
Light vehicle
≤ 30 kN
10
20/20
30
15

 

Considering a structure's durability, usability as well as aesthetics and functional availability of a structure, one should do everything possible to ensure appropriate protection of expansion slits.

Research shows that increased expenditures borne for this purpose, as well as high quality and professionalism of the relevant contractor reduce to a great extent the expenditures required for refurbishments, and limit difficulties encountered during a structure's lifetime.

This catalogue should be helpful during designing of equipment of expansion slits and the selection of appropriate profiles.
In case of any doubts, please contact our technical advisors. We are convinced that we able to provide optimum solutions even for the most uncommon situations.

In case of queries concerning the choice of expansion profile, please indicate:

  • expansion slit width,
  • expansion slit movement compensation,
  • structure profile installation height,
  • load amount,
  • point of installation.


If the use of expansion profiles is required on surfaces requiring full tightness (i. e. multi-storey parking lots), one can i. e. use the Deflex 500 expansion profile series. Their main advantage is full water-tightness of the executed expansion slit structures. The profile is made of aluminium, and has side covers made of stainless steel that protect the elastomer inlay from damage. The inlay is made of a synthetic material resistant i. e. to oils, bitumen masses, oxidation, acids, UV light, atmospheric conditions and temperature (from -30 °C to +60 °C), as well as ageing and traffic salt.
Should an inlay be destroyed, it can be replaced without it being necessary for the entire profile to be dismantled.
Below are presented components of the Deflex series 500 water-tight profile.

1. Aluminium bearing profile forms
2. Nitriflex synthetic material inlay
3. Stainless steel cover
4. Components to affix covers to the load bearing structure
5. Components anchoring the profile to the relevant surface
6. Epoxy resin-based evening out layer or modified cement mortar

During the design of expansion joints using this profile, one should note the joint of the insulation layer of the floor with the elastomer inlay.

The workmanship and expenditures related to refurbishments are incomparably higher with respect to an earlier proper selection and installation of profiles.
That is why, appropriately selecting Deflex expansion profiles is very important. This catalogue should be helpful material for the purpose of design of expansion slit execution and for the choice of appropriate profiles.
In case of any doubts, please contact our technical advisors. We are convinced that we able to provide optimum solutions even for the most uncommon situations..

The table below presents the most important properties of the individual Deflex expansion profiles simplifying the initial choice of the best solution.

Expansion profile types
Load type
Expansion slit width
[mm]

Material
Movement direction
Aluminium
Stainless steel Nitriflex®
Levels
Vertical
Horizontal
Profile wodoszczelne
DEFLEX 500 Na
      
30÷50
.
. . . . .
DEFLEX 500 NaL


30÷50
. . . .
.
DEFLEX 500 Nb


50÷70
. . . . . .
DEFLEX 500 NbL

50÷70
. . . .
.
DEFLEX 500 Nc

50÷70
. . . . . .
DEFLEX 500 NcL

50÷70
. . . .
.
DEFLEX 500 E


100
. . . . . .
DEFLEX 500 EK

100
. . . . . .
DEFLEX 501 a
60
. . . . . .
DEFLEX 505

35÷50
.
. . . .