Types of Joints in Building Construction: 4- Types of Joints

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Introduction

Joints in construction are one of the important elements that provide a functional and structural improvement to the structure. All building materials in the structure are subjected to expansion and contraction due to changes in temperature. They may crack under constant stress. Therefore, several types of joints are provided to the building or any other concrete structure in construction.

Types of Joints in Construction

The joints that are used in the construction works are as follows:

1. Expansion Joints
2. Construction Joints
3. Contraction Joints
4. Slip Joints

Expansion Joints

Joints are provided to accommodate the expansion of adjoining parts of the building and to relieve compressive stresses that might otherwise occur. Expansion joints essentially provide space between parts, sometimes with load transfer devices, and are usually filled with an expansion joint filler that is compressible enough to accommodate the expansion of adjacent parts. and has the ability to recover 75% of its original thickness pressure drops.

The expansion joints are usually provided for bridges, masonry structures, railway tracks, concrete pavement, pipelines and so on.

Also, read: Joints in Concrete Pavements: Transverse Joints & longitudinal joints

Is 3414 has recommended the spacing of expansion joints as follows

• Walls
  • Load bearing walls with cross walls at intervals. The traditional type of one brick thick or more: 30 meters intervals
  • Walls of warehouse-type construction (without cross-wall): 30 meters maximum intervals
• Chajjas, balconies and parapets: 6 to 12 meters
• Roofs
  • Ordinary roof slabs of RCC protected by a layer of mud phuska or other insulation media in unframed construction: 20 to 30 meters intervals.
  • Thin unprotected slabs: 15 meters intervals
• Frames
  • Joint in structure through slabs, beams, columns, etc, dividing the building into two independent structure units: 30 meter intervals in long uniform structures.
• Coping
  • It is as same as the joints in the roof slabs.

Construction Joints

Joints installed where construction stops if for some reason there is no place for interruption matches the planned location of the expansion or contractile joints.

Contraction Joints

These are basically separations or planes of weak spots added in concrete systems to localize shrinkage actions which might in any other case cause unpleasant cracks. They can be of any of the subsequent types:

Complete Contraction Joint:

In this form of joint, the bond among adjoining sections of a shape can be damaged absolutely via way of means of portraying one face with a bituminous fabric or via way of means of putting a layer of water-proof paper or roofing felt towards the face of the phase earlier than casting the following phase as much as it.

Partial Contracting Joint:

When structural balance is needed among sections of a strengthened concrete shape separated through a contraction joint, it’s far every now and then to retain the reinforcement throughout the joint. Due to the presence of reinforcement, the motion at those partial contraction joints is generally small.

Also, read: 11 Types of Bonds in Brick Masonry Wall Construction

Dummy Joint:

Dummy joints are used particularly in thin sections of concrete. In those joints, the plane of weak spots is created by forming a groove in both or every surface of the concrete. The overall depth of the groove is one-third to one-fifth of the thickness of the section.

Groove Joint:

A construction joint formed by a groove in a floor slab, wall, or pavement; is used to control random cracking.

Sliding Joints:

When variations in temperature, moisture content or loading result in a tendency for one part of a structure to move in a plane at right angles to the plane of another part it is necessary to provide a slip plane between the two parts thus enabling freedom of movement in both planes.

Sliding joints are usually formed by applying a layer of plaster to one of the surfaces and finishing it smooth before the other is cast on it or by any other approved suitable method.

Also, read: Types of Plaster Finishes

References:

1. Indian Standards Institution. (1968). IS:3414-1968: Code of practice for design and installation of joints in buildings. Bureau of Indian Standard
2. Indian Standard Institution. (2000). IS: 415-2000. Plain and reinforced concrete – Code of practice (4th rev.). Bureau of Indian Standard
3. Joint (building). (2022, August 20). In Wikipedia. https://en.wikipedia.org/wiki/Joint_(building)
4. Expansion joint. (2022, October 11). In Wikipedia.https://en.wikipedia.org/wiki/Expansion_joint
5. Dummy joint. (n.d.) McGraw-Hill Dictionary of Architecture and Construction. (2003). Retrieved October 17 2022 
6. Dummy joint. (n.d.) McGraw-Hill Dictionary of Scientific & Technical Terms, 6E. (2003). Retrieved October 17 2022 
7. Road joints. (2022, Sep 30). In Designing buildings. https://www.designingbuildings.co.uk/wiki/Road_joints