The traditional way to install chemical anchors is to inject an epoxy resin into a prepared, dust-free hole and then install an anchor rod through, say, an endplate
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The traditional way to install chemical anchors is to inject an epoxy resin into a prepared, dust-free hole and then install an anchor rod through, say, an endplate.

Once the resin hardens, the fixing is complete. The process imparts no stress into the base material during installation, so is the ideal solution for multiple fixes that have to be located close together or near edges.

Its only downside is that the quality of the bond relies heavily on the preparation of the hole in the base material – the  hole must be completely cleaned of drill dust.

“Preparing a hole for a chemical anchor is the most critical step in the installation process, which usually varies from one supplier to another,” explains Hilti anchor product manager UK Mark Fort.

“After drilling the hole, the installer has to blow out loose particles of the base material using compressed air. The remaining, more compacted particles in the hole then have to be loosened using a wire brush, and the loosened particles removed again by blowing air into the hole.”

Depending on the type of resin used, this ‘blow-brush-blow’ process for hole cleaning usually needs to be repeated twice; and for some resins, suppliers require repeating it up to four times. This effort-intensive process not only doubles the time it takes to install each anchor, but exposes the installer to dust particles.

Since this is the procedure used for the anchor’s load testing, Fort explains, if holes are not  prepared properly, the load capacity of the fixing will be drastically reduced. Concern that such anchors could fail at less than design load has led designers to take a conservative approach by either over-specifying the design loads or adding redundant fixings to account for the possible loss in capacity.

For extremely risk-averse sectors such as the nuclear industry, the installation procedure for chemical anchors is considered very critical. Andy Hurst, senior structural engineer for consultant Atkins’ nuclear business, says: “With chemical anchors, you are reliant on a third party to ensure the bond is correct. If the hole isn’t prepared properly then the anchor – particularly if it is installed to the underside of a slab – could drop out.”

The good news for designers with concerns about the installation of chemical anchors is that Hilti, after many years of research and testing, has developed a solution, the CE-marked HIT-HY 200 SAFEset system, which is designed to reduce potential errors during the installation of chemical anchors.

The Hilti HIT-HY 200 SAFEset system guarantees load capacities, without the need for hole preparation. This ETA-approved solution offers two installation methods, one using the Hilti HIT-Z anchor rods, the other using Hilti’s TE-CD and TE-YD Hollow drill bits.

Hilti HIT-Z anchor rods come with a cone-shaped helix, which works as a torque-controlled bonded anchor. This means that the performance of HIT-Z rod, when used with the HITHY 200 injectable mortar, is unaffected by uncleaned holes, both in dry or water-saturated concrete.

The hollow drill bits make subsequent hole cleaning completely unnecessary. Dust is removed while drilling is in progress using a universal vacuum cleaner. Then the HIT-HY 200 mortar is injected in the clean hole and a normal threaded rod or a steel reinforcement bar installed. This method not only saves time compared with traditional wire-brush hole cleaning, but also means a virtually dust-free working environment.

The introduction of SAFEset means designers now have a reliable solution that eradicates concerns about hole preparation, gives the assurance that the load capacities will be achieved in  accordance to the ETA approval documents, and improves productivity by eliminating the most tedious step of anchor and rebar installation.

“Specifying the HIT-HY 200 SAFEset system gives designers the confidence and peace of mind that anchor fixing and rebar will perform onsite just as has been designed on the drawing,” says Fort.

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HIT-HY 200 SAFEset applications


  • Post-installed rebar connections for concrete slab, column or wall extensions;
  • Heavy duty anchoring in cracked or uncracked concrete, for example, for steel beams, columns, manufacturing equipment or ledger angles;
  • Facade installation, steel and metal construction, installation of railings and safety barriers.

No cleaning required: HIT-Z anchor rods


When using a standard drill bit, compacted dust prevents a stable joint between the mortar and the base material.

When the rod is torqued, the surrounding mortar cracks, allowing the rod to act like an expansion anchor.

Expansion forces significantly increase friction against the sides of the borehole. This results in a torque-controlled adhesive expansion anchor system that takes up the highest possible loads in cracked concrete with no drop in performance under demanding conditions such as in wet or dry uncleaned holes.aaaahiltifn

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Holes that clean themselves: Hollow drill bits


When using a standard drill bit, compacted dust prevents a stable joint between the mortar and the base material.

This dust must be removed by brushing and flushing with compressed air before injecting the mortar. Drilling with a hollow drill bit connected to a universal vacuum cleaner removes the dust at the point of impact, meaning no additional steps.

This ETA-approved installation method eliminates the most time-consuming and load- affecting step in the installation process, whilst reducing exposure to harmful dust inhalation.aaaahiltifnb

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Editor’s notes


• Hilti, whose trademark red power tools are used on construction sites around the world, operates a direct sales model with more than 25 highly trained Hilti account managers, four engineers as well as four Hilti centres across Ireland
• For further information in relation to Hilti, including careers with the company, please visit the Hilti website: www.hilti.ie or www.hilti.ie/careers
• Hilti freephone: 1850 287 387

To download the free PROFIS Anchor software, please click here – link https://www.hilti.ie/software?utm_source=engineers_journal&utm_medium=website&utm_campaign=ie_16_11_engineers_journal&utm_content=software

http://www.engineersjournal.ie/wp-content/uploads/2015/11/hilti-d-1024x683.jpghttp://www.engineersjournal.ie/wp-content/uploads/2015/11/hilti-d-300x300.jpgDavid O'RiordanSponsored
  The traditional way to install chemical anchors is to inject an epoxy resin into a prepared, dust-free hole and then install an anchor rod through, say, an endplate. Once the resin hardens, the fixing is complete. The process imparts no stress into the base material during installation, so is the...