Anchor bolt vs. chemical seal?

The question of securing and supporting heavy loads is essential in construction projects. Two commonly adopted solutions are anchor bolts and chemical grouting. While each of these methods has its advantages, understanding their specific features and applications is crucial to making an informed choice. In this article, we take a closer look at these two systems, examine their differences, and help you identify which is best suited to your needs.

What is an anchor bolt?

The anchor stud, also known as the threaded rod, is a traditional technique favored by many for its simplicity and ease of installation. It often requires special attention to the diameter of the threaded rod to ensure optimum fixing.

Description and operation

An anchor stud is essentially a threaded metal rod that mechanically fixes into a base material such as concrete, brick or stone. It can support heavy loads thanks to the friction and mechanical locking achieved when inserted and tightened in a pre-drilled hole. To ensure correct installation, it's important to choose the right accessories and check that the anchor is suitable for the base material.

Anchor bolt types

There are several types of anchors on the market, including :

• Expansion studs: They expand when the nut is tightened, ensuring better grip.
• Knock-in plugs: mainly used for fixing lightweight components.
• Chemical anchors: involving a resin to create a strong bond between the stud and the base material.
  

When making your selection, it's crucial to take into account the length of the stem, as well as materials such as steel or stainless steel for specific applications.

Advantages and disadvantages

The use of anchor bolts offers a number of benefits, such as :

• Quick, easy installation.
• Ability to handle heavy loads efficiently.
• Generally lower cost than chemical alternatives.
  

For fixings in damp environments, we recommend the use of galvanized steel to prevent corrosion and extend product life.

However, they also pose certain challenges:

• Sensitive to vibrations which can weaken the fastener.
• Precise calculation to avoid any risk of failure.
• Limitations when used in inhomogeneous or friable base materials.
  

Chemical sealing

Chemical sealants use special resins to achieve a robust fastening and durable, particularly suited to severe conditions and specific applications where reliability is paramount. It is often preferred for materials prone to cracking, offering a superior grip thanks to the uniform distribution of the resin.

Basic principles and application

The process involves injecting a chemical resin into a pre-drilled hole before inserting a threaded rod. As the resin hardens, it forms an extremely strong bond between the rod and the base material, capable of withstanding heavy loads even in aggressive environments.

Chemical seal components

This system is based on two main components:

• Resin: Usually epoxy, polyester or vinyl ester, depending on specific requirements.
• The threaded rod: which may be metal or made of another corrosion-resistant material.
  

Advantages and limitations

Chemical sealing offers a number of advantages:

• Excellent resistance to tensile and lateral forces.
• Perfect for specific applications requiring high precision.
• Suitable for corrosive and underwater environments, although additional corrosion protection may be required.
  

The dimensions of the threaded rods must be carefully selected to match the requirements of the project, whether it involves fixing into concrete or wood.

However, this process has certain constraints:

• Often more expensive than traditional mechanical fasteners.
• Time needed for complete hardening.
• Extra care must be taken during application to ensure even distribution
  

Comparison between the two systems

When choosing between an anchor bolt and a chemical seal, there are a number of considerations to keep in mind:

Performance and load capacity

Anchor bolts are generally suitable for situations where heavy loads do not vary too much, and where the environment is not particularly aggressive. On the other hand, chemical sealing, thanks to the strength of the resin, offers superior load-bearing capacity and is ideal for extreme conditions such as the presence of moisture or corrosive chemicals.

Easy to install

Anchor bolts can be installed quickly and straightforwardly. Chemical sealing, on the other hand, requires a more meticulous and rigorous process to ensure a good bond, including time for the resin to cure properly.

Compatibility with base materials

For homogeneous base materials such as concrete, anchor bolts offer excellent fastening. However, for cracked, friable or composite materials, chemical sealing provides greater security and adhesion thanks to the uniform distribution of the resin. 

Costs involved

Generally speaking, the use of anchor bolts represents a more economical solution in terms of material and labour costs. Chemical sealing, on the other hand, can entail additional costs associated with the purchase of specific resins and the potential need for specialized installation techniques. Although it can be more costly, the advantages in terms of robustness and resistance to extreme conditions often justify the investment.

Typical applications

Each fastening method has its own specific use, depending on the requirements of the construction project.

Common uses for anchor bolts

Anchor bolts are frequently found in the following contexts:

• Fixing metal structures, such as scaffolding.
• Temporary anchoring on construction sites.
• Support for reasonably-sized mechanical and electrical equipment.
  

For projects involving woodenThe use of nails and appropriate nailing techniques may also be necessary.

Use of chemical sealants

Chemical sealants are preferred in situations requiring high strength and durability, such as :

• Structural elements subject to significant dynamic movements.
• Fixings in damp or underwater environments.
• Installation of overseas structures affected by salt corrosion.
  

When working in marine environments, stainless steel products offer greater resistance to salt corrosion, guaranteeing the durability of fasteners.

Conclusion

Making the right choice between an anchor bolt and a chemical seal depends on many factors from the nature of the project to the characteristics of the materials used. While dowels offer a fast, simple solution for effective fastening, chemical sealants are distinguished by their robustness and its ability to respond to extreme conditions. Each method has its own peculiarities, advantages and limitations; it's through a thorough understanding and judicious analysis of the requirements specific to each situation that the optimum selection will be made.