Installing resin bolts
Resin bolts comprise a two-part polyester resin-catalyst capsule and a steel bar with a plate and nut. Resin bolts are used in place of mechanical bolts in areas that require a higher strength fixing. This is how these bolts should be installed.
First, it’s critical to drill a hole to the correct diameter and length for the bolt being used to prevent wasting resin or reducing the bolt’s performance. Drill alignment is the most vital aspect of drilling, as it maintains the drilling forces, improves drilling speeds, and ensures strata support works as intended.
In addition, it is essential to drill the correct hole. Ideally, the diametric difference between the bolt and hole should be between 4 and 10 mm. Larger diameters can result in longer resin curing times, inefficient mixing of the components within the resin capsule, reduced load transfer, and reduced encapsulation length.
The ideal hole length should leave sufficient bolt thread protruding from the hole to accommodate the nut, plate, washer, etc. This is generally 50 – 60 mm shorter than the bolt. However, if the hole is over drilled, part of the resin capsule won’t be mixed by the bolt, which leads to reduced strength. In addition, the thread left on the bolt might be insufficient to tighten the nut, reducing tension and load-carrying ability.
Next, the capsules should be installed, taking care to insert the faster resin portion first when a tensioned system is used. The capsules should gently be pushed all the way into the hole with a bolt or insertion device.
Then, connect the bolt to a spinning device like a spanner and forcibly spin it into the hole while rotating through the capsule at the manufacturer’s recommended time at high rpm. An additional two to four second’s spinning after the back of the hole is reached will ensure complete mixing. Be sure not to exceed the manufacturer’s recommended spin time since that will cause damage to the setting resin.
Now, keep the bolt still in place until the resin has gelled enough to hold it in the hole before retracting the spinning device.
Finally, attach the washer and nut. However, most modern bolting systems have the plate and washer added before installation.
Contact Reunko Steel for details
Reunko Steel offers high-quality resin bolts and can design and install them to your specifications.
Our resin-anchored rock bolts are manufactured from hot-rolled high-tensile steel deformed bar and are available in standard lengths ranging from 0.6 metres to 3 metres. In addition, our standard lengths are colour coded for simple identification. We can also colour code your load indicator washers.
To find out more about our resin bolts, get in touch with one of our representatives today.