The Art of Using a Concrete Bolster: A Guide for Construction Professionals

When it comes to the construction industry, precision and accuracy are paramount. One such precision tool that plays a vital role is the concrete bolster. A wedge-shaped piece of metal, the concrete bolster is used to join and support two pieces of concrete. This guide will provide you with comprehensive insights into the use and application of concrete bolsters in construction projects.

The Purpose of a Concrete Bolster in Construction

A concrete bolster serves multiple purposes in the field of construction. Primarily, it is used to hold two pieces of concrete in place, creating a temporary joint that will harden as the concrete cures. This ensures a strong bond between the two concrete elements, enhancing the overall structural integrity of the construction project.

Bolsters are particularly useful when working with post-tension cables, rebars, or mesh above a surface. These materials often need to be supported above the surface when the concrete is poured, and bolsters provide the necessary support. They are typically inserted at a spacing of 5 inches (5” centres) to ensure even distribution and stability.

Using a Concrete Bolster in Construction Projects

Proper use of a concrete bolster involves several steps. Here's a detailed process to follow:

Step 1: Preparation

Before you start using a concrete bolster, ensure that all the necessary materials are on hand. This includes the concrete bolster itself, a hammer, and the pieces of concrete that need to be joined.

Step 2: Positioning

Position the concrete bolsters between the two pieces of concrete where they need to be joined. Make sure that the bolsters are securely placed and evenly distributed to ensure maximum stability.

Step 3: Insertion

Insert the bolsters into the designated slots or gaps between the two concrete pieces. It is important to ensure that the bolsters are correctly placed and aligned.

Step 4: Striking

Once the bolsters are in place, use a hammer to strike them. This action will force the bolsters to wedge themselves securely between the concrete pieces, creating a temporary joint.

It is crucial to strike the bolsters firmly but not too hard, as excessive force can damage the cement and weaken the joint. The right amount of force will ensure a strong, stable joint that will cure appropriately.

Types of Bolsters

There are several types of bolsters available in the market, each designed for different purposes. For instance:

Steel Bolsters

Steel bolsters are commonly used in construction due to their durability and strength. They can withstand the pressure and weight of concrete and provide a secure hold.

Concrete Bolsters

Concrete bolsters are more flexible and can be easily inserted and removed. They are ideal for temporary support or quick fixes in construction projects.

Roles in Post-Tensioning and Reinforcement

Bolsters play a significant role in post-tensioning and reinforcement processes. They are particularly useful in supporting post-tension cables, rebars, or mesh above a surface when the concrete is poured.

For example, in the installation of post-tension cables, bolsters can help in maintaining the alignment and spacing of the cables. This is critical for ensuring the cables are stress-free and can function optimally once tensioned.

Similarly, bolsters can support rebars or mesh in the formwork, ensuring that they are evenly distributed and remain in place until the concrete has cured. Properly positioning rebars and mesh is essential for creating a strong, robust structure.

Conclusion

The use of concrete bolsters in construction projects is a crucial aspect of ensuring structural integrity and stability. Whether you are working with post-tension cables, rebars, or mesh, understanding how to use bolsters effectively can make a significant difference in the quality of your work.

By following the steps outlined in this guide, you can ensure that your bolsters are used correctly, providing a strong and secure joint that will withstand the pressures of the construction process.