INJECTION BOLTS

• AP-KI-ø42 injection bolts

Intended use

• AP-KI-ø42 injection bolts are designed to support mine working areas as an independent or auxiliary roof support system.
  AP-KI-ø42 tube injection bolt is used to reduce static load on support systems in mining areas cut in adverse mining and geological conditions, such as:
  - fault zones,
  - areas of increased pressure (roadways),
  and are used:
  - to stabilize floor heaves,
  - to reinforce rock near sealed, fire and emergency stoppings,
  - to reinforce brick and concrete lining at shaft bottom, pump chambers, engine house, etc. in case of risk of their stability loss,
  - to reinforce the existing support of mine working area cross-cuts in case of their deformation,
  - as spiling when crossing abandoned workings or other working areas,
  - to form a mantle to prevent water leakage from shaft and small shaft lining.

Technical desription

• Bolt rod is made of 18G2A or R55 steel tube of ø30 x 6,3 and plain AP 600 or 34GS steel bar of ø18,3 mm.
  At the top the tube of ø30 x 6,3 has internal M20 thread for coupling with M20 threaded bar and 4 holes of ø6 for adhesive injection. At the bottom there is M30x2 thread.
  In the mid-section of the tube there is a stop collar to work with the seal. The seal is a rubber tube of ø42/ø31,5 mm and 200 mm in length. The seal expands after applying the tube and M30x2 nut.
  KE-4W/M20 shell with diameter of ø42 mm is the element which sets the bolt in the hole for the time of injection.
  The shell consists of 4 serrated leaves and one plug.
  A flat square washer of 8x150x150/ø31 is used with the bolt.

Technical data

Installation procedure

• Drill a hole of ø 44 ± 0,5mm in diameter and length equal to the length of the bolt.
  Place the expansion shell on one end of the rod and M30x2 nuts on the other.
  After inserting the bolt in the hole turn the rod for the shell to expand.
  Apply at least 250 Nm torque.
  After expanding the shell, 85 - 95 mm of the rod should protrude from the hole surface.
  After the shell has expanded, M30 x 2 nuts should be undone from the rod.
  Next, place the following elements on the rod in the right order:
  seal, tube, square washer, and then fix the M30x2 nut.
  Use a torque wrench to apply the initial tension of at least 30kN and to cause the rubber seal to expand in the hole.
  Then connect the bolt’s projecting threaded end with the injection pump and force the adhesive to the rock. During injection thanks to the expansion shell the rod will reduce the load on the roof caused by injection pressure.
  After the process of adhesive polimerization is over, the injection anchor starts to play the role of a classic adhesive anchor.
  Any adhesives with the required certificates and approvals can be used for injection.
• Adhesives used for consolidation of rock should have the following properties:
  -compression strength > 25Mpa,
  -setting time 15’- 25’,
  -be effective for dry and damp rock.