This Is Why Concrete Structures Need Expansion Joint Systems

Imagine being able to visually perceive the constant motions of a building caused by various factors such as;

1) Thermal?expansion?& contraction caused by temperature changes,

2) Sway caused by wind,

3) Expansion of materials caused by moisture,

4) Movements caused by seismic events.

This sight would certainly make the home owners be concerned about the protection of the structure against these movements. If the stress caused by these movements is not relieved, it can lead to cracking and spalling of the concrete structure. Accommodating this movement is an important aspect of building designing. This is made possible with the use of Expansion Joints Systems to relieve or take up the movement.

What is an Expansion Joint?

In?building construction, an?expansion joint?is a mid-structure?separation designed to relieve stress on?building?materials. It allows for independent movement & protects the structure from damage.

How Does Expansion Joints Systems Work?

A concrete expansion joint also known as a control joint, forms a break between the concrete and other parts of a structure to allow movement without causing stress. They are?required to break the bond between building sections to ensure the sections can separate. Since the material is compressible, it can accommodate the movement of adjacent materials.

As per IS- 456:2000, structures exceeding?45m?in length are designed with one or more expansion joint. As per IS 3414 which is a specific code for joints, it is stated as?30m.

Installation of Expansion Joints

The usual depth of an expansion joint is one fourth of the slab thickness, or more if needed. The expansion joint gap depends on the type of slab, such as floating slab floor, vehicle pavement, sidewalk, or monolithic slab foundation. It is also influenced by the slab dimensions, type of concrete, and the reinforcing materials being used.

1. Pre-Concrete Installation:

The provisioning of the expansion joints in slabs are made prior to concrete pouring. An individual expansion joint is created by the insertion of a flexible material that runs along the joint length.

2. Post-Concrete Installation:

Once the concrete is set, suitable tools are used for making channels in the poured concrete for placing of the joint materials.

These gaps are filled with an Expansion Joint System to fill in the void to ensure walkability, a complete building enclosure, waterproofing, and general serviceability of the structure.

We hope this brief article was beneficial.

Feel free to?get in touch?with us to discuss about the scope of Expansion Joint Systems for your ongoing or upcoming project.