Traditionally, when people think of chemical anchors, they imagine injection-style products. These come in tubes or packages of various sizes and need to be injected with either a caulking gun or some other form of installation tool.

In this article, we’ll be exploring the lesser-known capsule systems, as well as outlining the benefits of both anchor types.

Capsule chemical anchors

One reason why capsule anchors aren’t as widely recognised is the simple fact that there aren’t many options available in comparison to the wealth of injection anchors on the market. Simultaneously, capsule chemical anchors have historically been associated with significant physical and technical restrictions, as well as approval limitations.

However, thanks to improvements in the technology it has become possible to address many of these restrictions, bringing the pure benefits of a capsule system to the market. A great example of this is the new Hilti HVU2 capsule anchor. The HVU2 offers all sorts of benefits that make it a favourable alternative to injection anchor systems in various applications.

Physically, the HVU2 capsule operates on a ‘one-capsule, one-hole’ principle, allowing for no wastage. This is in addition to an extremely short five-minute curing time, which leads to increased productivity. The flexible foil material that the HVU2 capsule is made from - instead of glass - also ensures that it’s a safe system for on-site storage and use.

On the technical side of the equation, the HVU2 is approved for use in cracked concrete, unlike its predecessor the HVU capsule. This means that the HVU2 can be used for overhead installations, thanks to an arrow-shaped design that prevents the capsule from slipping out of its hole. The HVU2 is also approved for diamond-cored holes, and has been tested for both seismic applications and fire resistance.

Injection chemical anchors

While the HVU2 represents a new dawn for capsule anchors, injection chemical systems still have the benefits they’ve always been known and favoured for.

One example of this is a greater variety in terms of anchorage sizes and lengths, in comparison to the fixed sizes of capsule systems. Injection chemicals are also suitable for base materials such as masonry and natural stone, as well as rebar applications. Finally, there are still certain conditions - such as flooded or oversized holes - where an injection chemical remains the safest option.

The key takeaway from all of this is that capsule anchors are now a beneficial and viable solution for post-installed fastening to concrete, depending on various design or site conditions. However, capsule anchors are not necessarily the best option for all applications, and there are still certain cases where an injection system will either be more favourable, or the only possible solution.