Fastening and construction power tool manufacturer Hilti launched its new HIT HY-200 chemical anchor, used in anchoring and rebar applications, at the end of last year, replacing the current HIT HY-150 chemical anchor.
The new chemical anchor, which was developed at Hilti’s laboratories, in Liechtenstein, in Europe, will be used for standard anchoring applications with the conventional threaded rod and rebar; however, Hilti now has a European Technical Approval (ETA) for the chemical HIT HY-200 in conjunction with a special threaded rod called a HIT-Z rod to be installed in a hole that has not been cleaned and will still yield guaranteed loads.
“When it comes to post-installed anchors on construction sites, contractors need to drill a hole and blow it out with compressed air or a blow-out bulb and clean it with a wire brush – to remove all the dust in the hole,” says Hilti field engineer Previn Govender, adding that if the hole is not cleaned, the chemical product will bond to the dust instead of to the actual concrete, therefore, compromising the tensile capacity and performance of the anchor.
Hilti currently is the only manufacturer of fixing systems that has an ETA for the use of a chemical anchor in conjunction with a HIT-Z rod in an “uncleaned hole”, in the world.
In many cases on site, construction workers either do not clean the holes properly or they clean the holes quickly and ineffectively, resulting in the product bonding to the dust in the hole, thereby decreasing the performance of the anchor. One of the main benefits of this system is that contractors no longer need to worry about whether holes have been cleaned properly, and engineers that have designed the connection do not need to worry about whether the anchor has been installed correctly. By eliminating cleaning time, the system provides contractors with a productivity gain of 60%.
The Hilti HIT HY-200 also has the highest bond-strength of any chemical anchor on the market. Its design loads are between 20% and 40% higher than those of its competitors. The advantage of this is that it allows for anchors to be installed at shallower embedment depths compared with other products on the market, which means that you do not have to drill as deep as you would with a conventional product.
“For example, if you are post installing a Y12 rebar, most engineers would recommend that the embedment depth be at least 40 × bar diameter, therefore, you would have an embedment depth of at least 480 mm. “But owing to the new HIT HY-200’s high bond strength, you would only have to install a Y12 rebar at a minimum embedment depth of 110 mm to yield a tensile capacity of 33.2 kN,” Govender explains.
“The system is user friendly – any contractor working on any project in South Africa or throughout the rest of Africa can be assured of proper installation,” he concludes.