12p freyssibolt 1
TRANSCRIPT
FreyssiBoltThe complete high tensile mechanical
rock bolt solution for mining and tunneling
Fabricated in South Africa, the Freyssibolts are hot rolled from high
strength alloyed steel (950/1050 Mpa). They are subsequently cold worked
by stretching and then threaded over their full length by cold rolling.
The fabrication process provides a high quality thread ensuring
good fatigue resistance and a low susceptibility to stress corrosion.
Every single bar is stress tested up to 85% of the Guaranteed Ultimate
Tensile Strength.
They are combined with meticulously crafted bail type mechanical expansion
anchors to provide fast setting in temporary or permanent applications.
High tensile nuts, domed end plates, injection caps and oval load indicators
complete the system.
Bars are available in maximum lengths of 11.8 meters.
Beyond this length, extension sleeves allow bars to be
connected together.
The fabrication of the bars and the anchorages is carried
out under a quality assurance system in compliance with
the quality standard ISO 9001:2000. Bars and anchorages
comply with the requirements of international standards
related to prestressing tendons and anchorages.
Freyssinet & RYC reserve the right to make corrections, additions and deletions to this brochure without notice.
FreyssiBoltThe high tensile rock bolt
summary
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Advantages of FreyssiBolt
FressiBolt - Cold Rolled Thread
Installation instructions
Corrosion protection
Resin anchoring system
Accessories
Single and double protection system
Advantages of FreyssiBolt
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1/ Freyssibolts ensure the immediate compression between the rock and the shell
anchor and therefore, allows for immediate pre-stressing and nailing.
2/ The Freyssibolt expansion anchor will automatically center the bolt at the back of
the drilled hole.
3/ The lighter bar greatly facilitates handling and eases the installation. Freyssibolts
are up to 30% lighter than larger diameter bars with similar yield and ultimate load
characteristics.
4/ This high strength solution offers :
• Reduced cost per meter of tendon,
• Smaller diameter drill hole required because of smaller expansion anchor,
• Faster drilling,
• Less grout required.
From FB-19 through to FB-30 (Black and Galvanized)
Grade 950/1050
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FressiBolt - Cold Rolled Thread
NominalDiam.
Max.Diam.
ThreadPitch
YieldStrength
UltimateStrength
Mass Per Meter(BLACK)
19mm
22mm
24mm
25mm
30mm
20.96mm
23.96mm
25.96mm
26.96mm
31.96mm
5.0mm
5.0mm
6.0mm
6.0mm
6.0mm
22 Tons
30 Tons
36 Tons
40 Tons
60 Tons
25.7 Tons
35.0 Tons
42.0 Tons
46.7 Tons
70.0 Tons
2.216 kg
2.971 kg
3.536 kg
3.837 kg
5.525 kg
Comparison with low grade steel bars
The high grade Freyssibolt bars ensure an equivalent or higher yield and ultimate strength than
bigger diameter steel bars as described in the SANS 920:2005.
Type of barUltimate(Mpa)
Nominal dia.(Mm)
Crosssection (mm2)
Yieldmin.(kN)
UTSmin.(kN)
25mm Deformed bar
19mm Freyssibolt
34mm Deformed bar
24mm Freyssibolt
450
950
450
950
221
270
362
429
518
1050
518
1050
25
19
32
24
491
284
804
452
Expansion Shells (Black and Galvanized)
Material-Shells / Malleable IronPlug / Wedge / SG42
ExpansionShells
ThreadSize
Drill HoleSize
FB/S-19
FB/S-22
FB/S-24
FB/S-25
FB/S-30
20.96mm
23.96mm
25.96mm
26.96mm
31.96mm
45mm
45mm
45mm
51mm
64mm
- Hot-dip galvanizing to SABS / EN / ISO1461-1999, ASTM A-153
Yield(Mpa)
254
298
416
475
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COMPARISON GRAPH SHOWING DIFFERENCE BETWEEN19mm DIA. - (1050 Mpa UTS) - YIELD 950 Mpa PT BAR
AND 25mm DIA. - 450 Mpa - SANS 920: 2005 RE-INFORCED BAR
COMPARISON GRAPH SHOWING DIFFERENCE BETWEEN24mm DIA. - (1050 Mpa UTS) - YIELD 950 Mpa PT BAR
AND 32mm DIA. - 450 Mpa - SANS 920: 2005 RE-INFORCED BAR
Anchor Zone
The anchor zone is the area of the drilled bore hole that the tunnel/mine
roof support anchor will come in contact with and rely on to support
the mechanical tensioning system.
Tunnel/Mine roof support anchors require competent rock strata in
the anchor zone. The suitability of the rock anchor zone and specific
tunnel/mine roof support anchor to be used is best determined by
actual testing at the mine site.
Hole Preparation
Mechanical expansion anchors require a hole to be drilled into the
rock with attention paid to the length, diameter and straightness.
Rotary percussions or diamond drills both provide an acceptable drill
hole surface for use with the FreyssiBolt. Drill holes must be straight
and at least 70mm longer than the length of the tendon. Drill holes
must not be under or over sized. Hole straightness must be maintained
to allow passage of the mechanical anchor rod over the entire length
of the bolt. This is accomplished primarily with the attention of the
driller to down-pressure feed rate for a given rock type and the
amount of wear of the drill steel and bit.
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Grouting Procedure for Rock Bolts
In order for a rockbolt to be considered a permanent installation it must be encased in a high
quality cement grout. The principle function of the grout is to provide a pH enviroment which
does not permit the oxidation of carbon steels used in the manufacture of rock bolts while in their
service condition.
Materials
The grout required for rock bolting must be fluid enough to provide adequate flow to ensure
complete placement of grout. When the grout sets and cures it must be shrinkage compensated
so that it will not crack. Freyssinet Cement Grout for rock bolting is recommended. The grout must
be free of unwetted particles that might block the passages to ensure the grout is free of lumps
thorough mixing is required and the need to pass the grout through
a #8 sieve is recommended.
Equipment
Freyssinet offers several types of grout pumps. Please contact your
Freyssinet sales representative for more information
Timing
Bolts should ideally be grouted the same day they have been ins-
talled. Compressed air can be used to verify the open circuit along
the length of the bolt prior to grouting. Supply of the grout should
be done in accordance with the application drawing and orientation
chosen.
Installation instructions
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Service Life
The level of corrosion protection for a rock anchor depends on the service life of the
anchor, the type of environment and installation methods. If an anchor has a service
life of 2 years it is generally considered permanent. Permanent anchors should always
have some type of corrosion protection.
Ground aggressivity is generally influenced
by the following:
1. Electrical resistivity of the soil
2. pH value of the soil
3. Chemical characteristics of the ground water, rock, or soil
4. Moisture
5. Presence of oxygen
6. Stray electrical currents
Single and double corrosion protection systems
Freyssinet has a complete range of grout compounds to suit a variety of applications.
The grout compounds are designed to cater for single corrosion protected as well as
double corrosion protected installations. Cement grout filled corrugated tubing is often
used to provide an additional barrier against highly corrosive rock formations. These
installations are referred to as being “double corrosion protected”.
The anchor head, which consists of the bearing plate, hex nut and washer, is directly
exposed to air and oxygen and therefore requires considerable attention with regard
to double corrosion protection. In order to fulfill this requirement Freyssibolt system
proposes hot dip galvanizing of all steel components (bars and accessories).
Corrosion protection
Service Life
Class ProtectionConsequences
of failureClass Protection No Protection
Class Protection
Aggressivity Aggressivity
Class Protection
Permanent 24 months Permanent 24 months
Not know or aggressive Non aggressive Aggressive
Serious Not Serious
Non aggressive
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Corrosion protection
The Injection Compounds
Grout Compounds
Freyssinet has a complete range of grout compounds to suit a variety of applications. The grout
compounds are designed to cater for single corrosion protected as well as double corrosion pro-
tected installations. Freyssinet also provides quality factory grouting to enhance double corrosion
protection requirements.
Grouting Equipement
Freyssinet’s specifically designed grouting equipment will ensure quality and proper placement
of the grout.
Epoxy Coating
Epoxy coating of tendons prevent corrosion successfully in many applications because of the che-
mical stability of epoxy. Coating thickness is generally specified between 0.18mm to 0.30mm.
Epoxy coated tendons and accessories are however subject to damage during handling. Epoxy kits are
available for minor repairs in the field. The Epoxy coating is done in accordance with ASTM A-755.
Hot Dip Galvanizing
Zinc serves as a sacrificial metal corroding pre-
ferentially to the steel. Galvanized bars have
excellent bond characteristics to grout and
concrete and do not require as much care in
handling as epoxy coated bars. Typical galva-
nized coating thickness for steel bars and com-
ponents is between 70 - 100 microns. The
galvanizing is done in accordance with
ISO1461-1999 or ASTM A-153. The 1050mpa
high strength steel tendons should always be
mechanically cleaned (never acid
pickled/washed) to avoid problems associated
with hydrogen embrittlement.
Epoxy Coated Bars
Hot Dip Process
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Resin anchoring system
Freyssinet provides a wide range of two component chemical adhesives ideally suited for anchoring
threaded rod. Adhesive Anchoring products are available as injection cartridges with a plastic mixing head
and a two component Capsule. Adhesive Anchoring products can be used with a screen tube or plastic
cone to anchor into solid materials such as rock or concrete. Contact your Freyssinet Sales Representative
of Freyssinet Technical Department for assistance in your product selection and technical information.
Adhesive anchors
Dome Plate (Frey-Dome1)
The Dome Plate comes in standard size of 8mm x 150mm x 150mm.
Other sizes are available on request.
Grout Tube (Frey-GT1)
Heavy duty Grout Tube
Heavy Spherical Nut (Frey-SN)
Heavy Hex Nut (Frey-HN1)
Custom nuts supplied in accordance with the diameter of each tendon.
Outside diameter Inside diameter Quantity per roll
1/2”
5/8”
3/4”
12.7mm
15.875mm
19.65mm
3/8”
1/2”
5/8”
9.525mm
12.7mm
15.875mm
150m per roll
150m per roll
150m per roll
Accessories
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Single protection system19mm and 24mm FreyssiBolt principle design
Double protection system19mm and 24mm FreyssiBolt principle design
1 bis, rue du Petit Clamart - 78140 Vélizy-Villacoublay - France
Tel.:+33 1 46 01 84 84 - Fax:+33 1 46 01 85 85
www.freyss inet .com - [email protected]
Contact: Pierre Gruchy ([email protected])
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