Different Types of Adhesive Anchors
Adhesive or chemical anchors bond metal pegs, rods, or rebar to substrate materials. These kinds of anchor work on a wide variety of substrates, including masonry, cracked concrete, and green concrete. They are also regularly used on standard-strength concrete, including large infrastructure projects, such as bridges, roadways, and airport runways.
Chemical anchors are suitable for these high-load applications because the bond created by most types of adhesive is stronger than both the substrate it is installed into and the metallic anchor used. Additionally, the base materials hold very little load-bearing stress. Instead, this stress is transferred to the cured adhesive. This gives them an advantage over expansion anchors and other mechanical options, as mechanical anchors have points of stress that can weaken them.
Additionally, adhesive anchors can be used in situations where mechanical anchors would likely fail, including:
- In cracked concrete
- In hollow substrates
- Close to the brittle edges of concrete structures
- In groups close together
- In concrete of unknown strength and quality
Adhesive anchors come in a variety of strengths and chemical makeups. Most are either polyester or epoxy based.
The Five Main Types Of Adhesive Anchors
There are five main kinds of chemical anchors. Each of these can be combined with a selection of studs, bolts, and rods to connect new structural or nonstructural elements to a substrate. The five main adhesive types used in chemical anchors are:Unsaturated polyester chemical anchors
Unsaturated polyester chemical anchors are two-part resins designed for use in mortar specifically, although many now also work in concrete and other substrates. Polyester resins are usually dissolved in styrene, but styrene-free polyester resins are also available. The wide variety of formulas for this kind of adhesive anchor means unsaturated polyester chemicals are very versatile. Some are even suitable for cracked concrete and seismic conditions.
Polyester chemical anchors
A cousin of unsaturated polyester chemical anchors, polyester chemical anchors are another popular two-part injectable anchor system. They’re very easy to use and have a wide variety of applications, including installing handrails, putting up building facades, and making post-installation rebar connections. Polyester chemical anchors are suitable for medium loads and can be used with threaded rods and rebar. It isn’t suitable for cracked concrete or concrete with an unknown strength.
Pure epoxy chemical anchors
Epoxy is one of the most multi-functional and popular adhesives for chemical anchors. Pure epoxy chemical anchors are another two-part adhesive, and they need a 1:1 mix to bond. They can be used in seismic conditions and cracked concrete because it was developed for structural applications, specifically installing rebar to connect concrete to concrete. It has an extremely high bond strength and takes the load stress itself rather than transferring any into the base materials.
Epoxy acrylate chemical anchors
This two-component resin is styrene-free and designed as a very strong, fast-curing option in both masonry and concrete. It holds very high-stress loads, including structural loads. Epoxy acrylate chemical anchors are appropriate for use in damp conditions and corrosive environments, so they can be used in factories, municipal settings, difficult climates, and even underwater if applied correctly.
Hybrid anchor systems
Hybrid system chemical anchors consist of a fast-curing adhesive that allows you to add weight to it far earlier than you could with epoxy. This kind of system is used for both threaded rods and rebar in concrete. It’s commonly used to secure structural connections for steel beams and columns. The extremely reactive adhesive mixture fills in all flaws in the substrate, creating additional load strength. As the hybrid system is quick-curing, you have less time to make adjustments than with some other chemical anchors. Compared to mechanical anchors, the ability to make small changes is still a positive point for hybrid systems.
This two-component resin is styrene-free and designed as a very strong, fast-curing option in both masonry and concrete. It holds very high-stress loads, including structural loads. Epoxy acrylate chemical anchors are appropriate for use in damp conditions and corrosive environments, so they can be used in factories, municipal settings, difficult climates, and even underwater if applied correctly.
Hybrid anchor systems
Hybrid system chemical anchors consist of a fast-curing adhesive that allows you to add weight to it far earlier than you could with epoxy. This kind of system is used for both threaded rods and rebar in concrete. It’s commonly used to secure structural connections for steel beams and columns. The extremely reactive adhesive mixture fills in all flaws in the substrate, creating additional load strength. As the hybrid system is quick-curing, you have less time to make adjustments than with some other chemical anchors. Compared to mechanical anchors, the ability to make small changes is still a positive point for hybrid systems.
Hybrid Anchor System
Hybrid system chemical anchors consist of a fast-curing adhesive that allows you to add weight to it far earlier than you could with epoxy. This kind of system is used for both threaded rods and rebar in concrete. It’s commonly used to secure structural connections for steel beams and columns. The extremely reactive adhesive mixture fills in all flaws in the substrate, creating additional load strength. As the hybrid system is quick-curing, you have less time to make adjustments than with some other chemical anchors. Compared to mechanical anchors, the ability to make small changes is still a positive point for hybrid systems.
Selecting The Correct Adhesive Anchor System
When you’re selecting the correct adhesive anchor system for your construction project, you should consider:
- Suitability for the base material, whether that’s concrete, masonry, a hollow wall, or any other substrate.
- The environment the adhesive will be in — for example, will it be exposed to dampness, chemicals, or extreme heat?
- Curing time — do you need a quick cure to allow other teams to begin work? Is a slower cure a good idea because you may need to make adjustments?
- The practicality of mixing your materials if you have a two-part adhesive. Poorly mixed chemical anchors can fail.
Adhesive Anchor Shelf Life
When you choose an adhesive anchor, you should consider the shelf life of your adhesive. This is particularly important when buying your adhesive in bulk, spending a fair amount of money, or not sure exactly how much you will use. This isn’t uncommon with non-typical substrates like porous or cracked concrete. If you do have to store adhesives, they usually last between 9 months and 2 years, although this depends on both the formula and who manufactured the chemical adhesive.
When In Doubt, Use Chemical Anchors
One of the best things about chemical anchors is that they can be used in substrates that you don’t have a lot of information on. Whether the concrete you’re inserting them into is old and of unknown strength, or you know it’s porous or weak, chemical anchors are a great choice. The resin or adhesive you use will bare the load you put on your anchor, and the adhesive itself will fill any imperfections in your substrate. It should also be noted that you can embed almost any length of rod into the borehole in your substrate. As long as you properly mix your two-part adhesive and fill your borehole, a longer rod increases the load capacity.Why White Cap?
At White Cap, we have everything you need to install chemical anchors. From epoxies to the metal anchors they secure, you’ll find it all at White Cap, whether you visit one of our 360+ stores or online. With next-day delivery, you’ll have your anchoring system in plenty of time to install it!Additionally, if you need help deciding which adhesive anchor is best for your next job, you can get in touch with a local White Cap expert. You’ll get a call within two hours, and our White Cap experts can talk you through the pros and cons of various adhesive anchors as well as local weather conditions and building regulations.
Check out these articles to learn more about Adhesive Anchoring
Factors to Consider When Buying a Caulk Gun
Selecting the Right Caulking Gun Type for Your Project
Maintaining Your Caulking Gun
What are Adhesive Anchors?
Benefits of Chemical Anchors
The Different Types of Adhesive Anchors
Mechanical vs. Chemical Anchors
Determining a Tension Test Load
Infrastructure Applications for Adhesive Anchors
