About Sika Rokkon R (FS)

Rock bolting is only as reliable as the anchor that holds the bolt in the rock, and in a working mine or a tunnel heading the window to install that anchor is short. Sika Rokkon R (FS) is a two-part polyester resin capsule built for exactly that situation. Each cartridge carries a very high quality polyester resin in one section and its catalyst in another, measured in precise proportion at the factory so there is nothing to gauge or mix on site. The crew simply inserts the right number of capsules into a cleaned borehole and spins the bolt through them. The rotation ruptures the film, shreds it and forces resin and catalyst together, and the homogeneous mix fills the annular gap between bolt and rock, gripping the bar firmly and permanently.

What makes the (FS) grade suited to production mining and tunnel advance is speed with control. The pot life is a deliberate 3-4 minutes at +22 C, long enough to spin and seat the bolt yet short enough that the anchor develops load-bearing strength almost immediately. Because the material is lab-tested and pre-packed, it sidesteps the two classic problems of on-site anchoring, prolonged set and unreliable load capacity, that plague hand-mixed cement or improvised grout. The cured resin is chemically robust too, unaffected by fresh or salt water, oils, grease, petrol and salts, so the anchorage stays sound in the wet, corrosive conditions common underground. For contractors and mine planners in India working to NGT and DGMS-driven ground-support schedules, that combination of quick turnaround and dependable, distributed anchorage is the core reason to specify it.

The technical insight

The anchorage mechanism is chemical, not mechanical, and that is the whole point. In a conventional expansion-shell bolt, load is carried at a single point where the shell bites the rock, which concentrates stress and can slip under vibration. Rokkon R (FS) instead cures into a continuous resin column bonded to both the bolt and the borehole wall along its full contact length. Load is therefore distributed rather than localised, so no single zone of rock is asked to carry a stress spike, and the bond is intrinsically resistant to the vibration and blast shock of an active face. The cure itself is an exothermic polymerisation triggered the instant the catalyst mastic meets the resin during spinning, which is why setting time is inversely proportional to temperature: a warm heading gels faster, a cold one slower. That relationship is worth designing around, because it is also why capsules stored in a cool room must be brought back to ambient before use, otherwise spin and hold times stretch. The result of a correct install is an anchor that develops roughly 22 MT of pull-out resistance per running metre within a day and a tensile bond strong enough that failure, when forced in test, occurs in the surrounding concrete or rock rather than at the resin interface.

Where it is used

• Roof and rib bolting to support freshly exposed strata after each blast in underground coal and metal mines
• Systematic rock-bolt support for road, rail and metro tunnel crowns and sidewalls
• Ground reinforcement in hydropower headrace, pressure and tailrace tunnels
• Point anchorage where only the bolt toe is resin-encapsulated for a mechanical-style anchor
• Full-column grouting where the entire bolt length is bonded for permanent, distributed support
• Portal, adit and slope-face stabilisation during excavation and permanent works
• Anchorage in wet or chemically aggressive underground sections where cement grout would be unreliable
• Rapid re-support of scaled or loose ground during production cycles that cannot wait for cement to cure

Key advantages

• Very fast, controlled set with a 3-4 minute pot life at +22 C for quick bolt installation on a live face
• High early strength, reaching 60 N/mm2 compressive within one hour so support is effective almost immediately
• Distributed full-column anchorage that avoids the localised stress peaks of point-anchor expansion shells
• Permanent anchorage unaffected by vibration and blast shock from ongoing production
• Cured resin resists fresh and salt water, oils, grease, petrol and salts for durability in corrosive ground
• Factory pre-packed and lab-tested, removing on-site mixing error and inconsistent set
• Pull-out resistance of about 22 MT per running metre within a day, testable as early as 30 minutes after install
• No wet slurry, wash-down or plant, making it clean and quick compared with pumped cement grout

Limitations & considerations

• Must not be inserted into boreholes with running water, which disrupts the resin and compromises the bond
• Setting time is inversely proportional to temperature, so cold headings gel slower and hot ones faster, requiring crew awareness
• Capsules stored cool must reach ambient temperature before use or spin and hold times extend unpredictably
• Short six-month shelf life from date of production demands strict stock rotation and disciplined storage
• Correct spinning technique and hole cleaning are essential, as under-mixed or dust-fouled anchors underperform

Selection & best practice

Specifications

Industry use cases

How we position Sika Rokkon R (FS)

Rokkon R (FS) is the fast-set grade within Sika’s Rokkon rock-bolting family; where site conditions or client specs favour a cement-based anchor rather than resin, the companion Sika Rokkon C cementitious cartridge covers the same rock-stabilisation duty with different handling and cure characteristics. For general structural fixing and anchoring outside the mining and tunnelling context, Sika AnchorFix modified-acrylic and epoxy anchoring adhesives are the appropriate choice. Space Arc also supplies these ground-support and anchoring lines alongside Fosroc’s grouting and anchoring range, including Conbextra cementitious grouts and Lokfix epoxy anchoring, so we can match the anchor system to the ground, the load case and the client’s approved-vendor list. Talk to us with your bolt type, hole geometry and strata and we will recommend the right capsule count and grade.

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