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Application

Expansion shell cement bolts type AP-KRC-ø42 are designed to be used for roof and ribs support in mine working areas as an independent or secondary support system.

Expansion shell cement bolts type AP-KRC-ø42 are designed to be used also in tunnels.

Technical description

Bars are made from:
- reinforced ribbed bar of dn=20 mm in diameter from steel 34GS according to PN-82/H-93215 standard or
- reinforced ribbed bar of dn=20 mm in diameter from steel AP-E460 according to ZN-98/AP-5+A1:1999 standard or
- reinforced ribbed bar of dr=18,2 diameter from steel AP 600 according to ZN-95/AP-3+A1:1999 standard or
- reinforced ribbed bar of dn=20 mm of B500SP or B500NC steel.

Expansion shell KE-4W/M20 or KE4-2K/M20 diameter ø42 mm is to fix the bolt in a hole.

Cement injecting set I and II consist of special spherical washer ø62,5 mm and plastic pumping pipe. There are special sleeve (bulb) diameter ø65 mm and pumping plastic pipe. For these sets are applied round and square washers 8mm thick and hole ø54 mm.

Special made bolt is rust protected:
- type I – hot deep galvanized, cover thickness 60÷90 μm,
- type II – hot deep galvanized, cover thickness 60 ÷ 90 μm and epoxy coated.

 

Technical data

 

SpecificationsValue

Rod diameter

dn = 20 mm

dr = 18,2 mm

Rod length

M20

Rod length

from 1300 to 5000 mm (or other acc. to customer need)

Shell diameter KE-4W/M20

ø42 mm

Shell length KE-4W/M20

93 mm

Shell diameter KE4-2K/M20

ø42 mm

Shell length KE4-2K/M20

136 mm

Bolt capacity

min 120 kN

Useful load

170 kN

 

Installation procedure (type I)

Drill a hole of diameter ø 44 ±0,5 mm of the length equal to the rod length.
Insert the rod then rotate in order to shell expand. Expand shell with the toque at least 250 Nm. Mount injection head of the set on the spherical washer and expand it.
Prepare cement-water mixture of ductile consistency. Start pumping mortar through injection head controlling air outflow. Keep pumping until mortar flow out from the hole in the washer. After finish disconnect injection head.
Attention : for installation was used fast-coupling seat for ø42 mm tube and dimensions D= ø64 mm, A=22 mm index MU-2945-2 of TUBES company.
Fast-coupling seat works as injection head.

Installation procedure (type II)

Drill a hole of diameter ø 44 ±0,5 mm of the length equal to the rod length.
Insert the rod then rotate in order to shell expand. Expand shell with the toque at least 250 Nm. Insert pumping hose into ø15 hole in connecting sleeve.
Prepare cement-water mixture of ductile consistency. Start pumping mortar through injection head controlling air outflow. Keep pumping until mortar flow out from the hole in the washer.

Exemplary recipe of inject

Inject for bolt setting is the water and cement mixture. Cement should be CEM brand and minimum 32.5R I class.
Recommended volume proportion : water - 3 volumes, cement – 7 volumes.
Weight proportion : water : cement = 0.3.
Filled up mixer with water on slow rotations then add cement and increase rotation when mortar is getting thicker. When consistency will become homogeneous pump inject into the bolting holes.
Attention : recipe should be changed according to geological conditions.