Rock surrounding underground excavations needs to be reinforced and stabilized in order to provide for a stable and safe working environment.
The ERB - Expandable Rock Bolt is a full column anchored rock bolt that forms a mechanical interlock between the borehole wall and the bolt over the full bolt length. This is achieved by inflating the ERB by means of high-water pressure. When the pump stops the ERB immediately provides full rock support action. Also, when the ERB is inflated it causes a contraction in the bolt length which effectively tensions the face plate against the rock surface.

The ERB is a cost-effective means of rock reinforcement in a variety of rock conditions from soft to hard rock. It is flexible and will allow variations in the borehole diameter. The ERB is designed to accommodate large rock movements and still maintain its high load bearing capacity. Further the ERB is an environmentally friendly rock reinforcement solution with no cement grout or other chemicals required to anchor the bolt. The ERB may be installed manually or fully mechanist -just add water. The main applications of ERB are:
• Underground mining
• Underground civil engineering work
• Road- and railway tunnels
• Underground storage facilities

	ERB 120 ERB 120+	ERB 160 ERB 160+	ERB 240 ERB 240+
Bolt Diameter	28mm	38 mm	38 mm
Profile Diameter	27.5mm	36 mm	36 mm
Material thickness	2mm	2mm	3mm
Upper brushing diameter	28mm	38mm	38mm
Inflation Bushing diameter	30/37 mm	41/48 mm	41/48 mm
Hole Diameter	32-39 mm	43 - 52 mm	43 - 52 mm
Minimum Breaking Load	120 kN	160 kN	240 kN 230 kN
Minimum Elongation	10%/20%	10%/20%	10%/20%
Typical Elongation	15%/30%	15%/30%	15%/30%
Standard Lengths	1.5 - 4.0 m	2.4 - 6.0 m	2.4 - 6.0 m