Product examples
An example of a product manufactured by processing ZAM™ is introduced.
NIPPON STEEL Coated Steel Pipe Co., Ltd.
Product name
RPE rock bolt
Product description
Used as rock bolts for tunnels (permanent support materials).
One point
A rock bolt is a type of anchor bolt used for preventing collapse of the inner wall of an excavated tunnel. Rock bolts currently available use cement mortar as a fixing material and therefore require several hours for stabilizing.
With this RPE rock bolt, a ground clamping effect can be obtained in as short as 30 seconds by hydraulically expanding the irregular shaped steel pipe. In addition, it has overcome the problem of low corrosion resistance, which has been a weakness of conventional products with expanded steel pipes.
Product features
①High corrosion resistant material
This product uses ZAM™, which is a prestress force-retaining elastic body and at the same time a high corrosion resistant steel sheet involving only a minium of thickness reduction. It contribute greatly to the enhancement of long-term corrosion resistance of a tunnel.
②High installation efficiency
Multiple (2 to 5) rock bolts can be installed at one time.
③Reduced environmental load
The compact and lightweight high pressure generator and the seal head lighten the work load.
Advantage of adopting ZAM™
Previously used for temporary works because its material did not have an anti-rust function (supplied as pickled).
The adoption of ZAM™ has made this product applicable as a tunnel pattern bolt - a quick-acting, highly corrosion-resistant bolt for permanent use.
The adoption of ZAM™ has made this product applicable as a tunnel pattern bolt - a quick-acting, highly corrosion-resistant bolt for permanent use.
Product specifications
| Field | Application | Advantages | Coating weight symbol | Chemical conversion treatment | Thickness（mm） |
|---|---|---|---|---|---|
| Civil engineering |
Rock bolt main body (12-ton proof strength) |
High corrosion resistance, high concrete resistance |
90 | Untreated | 54.0 mm in dia. X 2.0 (expanded) |
| Rock bolt main body (18-ton proof strength) |
54.0 mm in dia.
Rock bolt main body (18-ton proof strength) X 2.3 (expanded) |