SSAB ERB, Expandable Rock Bolts – A new member to infrastructure construction product family
09.6.2016 8.00 CEST 6 min luettu
SSAB ERB offers fast and reliable roof reinforcement for underground mines and tunneling applications. The product shares similarities with other SSAB’s Infrastructure products like utilization of own steel and tube production, raw materials upgrading with own value adding and easy installation for the end customer. SSAB has a long experience with the product. “SSAB has been a producer to several leading distributors of rock bolts worldwide since 1979. With own steel manufacturing, profiling and assembly of final SSAB ERB product in Virsbo, we have guaranteed excellent production control and high quality product for over 30 years”, says Hans-Inge Pettersson, Sales Manager.
Figure 1. SSAB has over 30 years of experience with ERB, says Hans-Inge Pettersson.
SSAB ERB with guaranteed mechanical properties are produced in Virsbo, Sweden
Expandable rock bolts are manufactured from unique SSAB steel in the Nordics. Each production stage from steel manufacturing to profiling and assembling of rock bolts belongs to SSAB’s own production and quality control chain. Quality control secures that the product is regularly tested to secure quality and safety.
Figure 2. SSAB ERB consists of folded steel tube with upper bushing and inflation bushing welded at each end of the tube. Face plate can be delivered as option.
SSAB’s expandable rock bolts are available in two types, called SSAB ERB and SSAB ERB+ series. Each series includes products with three load capacity variants: SSAB ERB 120 with a load capacity of 12 mt, SSAB ERB 160 with a load capacity of 16 mt and SSAB ERB 240 with load capacity of 24 mt. Elongation characteristics is the main difference between the series: cold formed series SSAB ERB have elongation A5 ~ 15 % and cold formed and normalized series SSAB ERB+ have extraordinary elongation A5 ~ 30 %.
Reinforcement with expandable rock bolts
Rock walls in underground mines and tunnels need to be secured in order to not collapse or cave in. The reinforcement with expandable rock bolts (SSAB ERB) arrests crack formation and propagation. Reinforcing occurs by expanding i.e. hydroforming the bolt against the drill hole buy using only high water pressure. The expansion of the bolt creates a friction and interlocking anchor. There is immediate full length support for faster excavation, no waiting for grouting to set.
Figure 3. Before and after expansion.
You can contact SSAB in any questions related to roof reinforcement solutions.
Sales Manager, Expandable rock bolts
+46 70 5915912