Liebig anchors have wide variety of applications across the civil engineering sector.
When global fastener manufacturer EJOT became custodian to the Liebig anchoring brand, the group’s manufacturing portfolio expanded overnight. The physical size of Liebig anchors also added a new dimension – in particular, the Ultraplus undercut anchor.
Undercut anchors present the strongest option for fixing into concrete. The name describes the process of “undercutting” a special flared cavity within the substrate. When in place, the anchor utilises the full capacity of the concrete to resist the application load.
The Liebig Ultraplus design offers the highest tensile and shear performance of any other undercut anchor on the market, from 320KN tensile load and beyond, so it is easy to appreciate why structural engineers around the world respect this unique anchoring technology.
Diameters range from 10mm to 36mm with corresponding product names – M10 to M36. The modular design means that lengths can be bespoke to suit a particular application – but there are many M36 variants in place that measure up to 1.5m.
Ultraplus in application
With European Technical Approvals for cracked and uncracked concrete that includes seismic and load case fire, think of anywhere where structural and human safety is paramount.
Paul Papworth is EJOT UK’s Liebig specialist. Recent projects that he has been engaged with include installations at a hydro power plants, nuclear waste and waste treatment plants, plus a nuclear-powered submarine testing bed. Papworth explains: “For the hydro power plant, M36 diameter stainless steel Ultraplus anchors were used to hold down a tunnel liner in the main water inlet tunnel. Ultra-high performance anchors were needed here due to a significantly high rip force that was created by the water passing through a 90˚ inlet. These massive forces had previously ripped up the 25mm steel liner.
“The nuclear waste plant utilised 1.2m long M24 Ultraplus. Significantly high load and safety factors, including risk of failure, were the driving factors behind specification. The length of anchor chosen meant that sub-level utilities could be avoided. Anchor strength was also enhanced, providing extra strength.
“M36 diameter zinc plated Ultraplus anchors were installed at a chimney stack on a waste treatment plant in the north of England. An immediate take up of load was required – which is one of the Ultraplus anchor’s unique application benefits.
“Special assembly M20 Ultraplus anchors were developed for a nuclear submarine testing bed. Again, ultra-high loads and significant failure risk drove specification. These special anchors were designed so that they could be installed permanently without relaxing the pretensioning when the testing beds were consequently removed.”
There are of course the more regular applications, for example replacing misplaced or misaligned cast-in anchors for holding steel columns on more traditional construction projects. The Ultraplus anchor with its high loads, ease of installation and immediate take up of load is a quick and simple fix to overcome what otherwise would be a costly re-work.
- Produced in association with EJOT