Our TE-YRT roughening tool and HIT-RE 500 V3 epoxy mortar make the difference
Getting the best epoxy mortar bonds in diamond-cored holes
Chemical anchoring applications always come with a certain amount of complexity, but few compare to the difficulty associated with installing rebar in deep, diamond-cored holes. This is one of the most challenging processes contractors will ever come across on a job site, and a big part of the complexity is due to the many different steps involved.
It's not a procedure that is particularly common, often being reserved for specialist scenarios. Even so, in situations where it is necessary, it's imperative to get the process right and ensure that each bond is as strong and stable as possible.
The challenges of installing rebar in diamond-cored holes
Typically, installing rebar in deep, diamond-cored holes is a process required when a structural column needs to be extended. In these scenarios, existing rebar needs to be extended for maximum stability, and an engineer will often specify a very deep hole for this. The best way to achieve these deep holes consistently is through diamond coring, particularly in scenarios where contractors will need to drill through existing rebar as well as cracked or uncracked concrete. Hilti Trade Manager Martin Stirling explains some of these challenges:
"When you're extending rebar through a column, you're usually going to at least glance through another piece of rebar, and the only way to penetrate through this effectively is with diamond coring," he says.
However, it's critical to keep in mind that the sides of a diamond-cored hole are much smoother than when using other drilling methods, resulting in less surface area. This means that holes often need to be very deep, in order to compensate for this smoothness and achieve maximum bond strength with an epoxy mortar.
Here at Hilti, we recognise that this can cause problems and inefficiency on a construction site, which is why we've introduced two innovative products to make the process of installing rebar in diamond-cored holes much easier. These products are our TE-YRT roughening tool and HIT-RE 500 V3 epoxy mortar.
The TE-YRT roughening tool
Rather than drilling deeper to compensate for the smooth sides of a diamond-cored hole, it's much easier and more effective to simply provide each hole with rougher surfaces, and more surface area. This is where the Hilti TE-YRT roughening tool comes in, providing a simple way of creating more surface area for an epoxy to bond to.
"The TE-YRT roughening tool dramatically increases the surface area within a hole, meaning that contractors don't have to drill as deep and can ensure each piece of rebar is installed with maximum strength," explains Martin.
Because every construction site is slightly different, there is a variety of different sizes available within the roughening tool range. This means that regardless of hole diameter, contractors can use a matching tool that fits perfectly and roughens the hole without causing any damage and potentially compromising the bond. Using the roughening tool is quick and easy, with the process taking only a few minutes to complete. The tool provides a simple solution that can be relied upon in situations where dependability is critical.
HIT-RE 500 V3 epoxy mortar
This is the third version of Hilti's HIT-RE 500 epoxy mortar, and it's a product that has come to define our focus on innovation and continued improvement over the years. The new version provides a lot more strength than then the previous one, thanks to a new chemical composition that's been refined to offer the best bond strength in situations where nothing else will do. In fact, the HIT-RE 500 V3 offers by far the best bond strength in its class, so contractors can rest easy knowing that each piece of rebar that they install will last the distance.
"What also happens is that as the holes and rebar get larger on certain projects, the strength difference between HIT-RE 500 V3 and competition becomes greater, making it an ideal epoxy for all sorts of different applications regardless of size," says Martin.
Like previous versions, HIT-RE 500 V3 also boasts a long working time, giving contractors more control over the installation process without having to race against the clock. And when the epoxy has cured, it will be harder than concrete.
While both the TE-YRT roughening tool and HIT-RE 500 V3 epoxy mortar make installing rebar in diamond-cored holes easier, the process really goes up a level when the two are used together. In tandem, the products allow for far shallower holes and incredible bond strength - saving time as well as requiring less epoxy volume.