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
The term “rock bolt” refers to an anchor bolt used to prevent tunnnels from collapsing after excavation.
The rock bolt currently in most frequent use requires several hours for fixation.
This RPE rock bolt enables one to obtain a bedrock clamping effect in only several seconds by hydraulically expanding deformed steel pipes. This product has also overcome the problem of corrosion which is a drawback of conventional rock bolts of expanded steel pipes.
Product features
● Contributes significantly to long term durability of tunnels.
● Two or more bolts can be driven at the same time.
● Shortens construction time.
● Can be used not only as system rock bolts but also as bolts for forepoling, face bolts, or measures against swelling.
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) |