No reduction in load capabilities as threads exceed the nominal bar diameter. Robust thread design accepts harsh conditions without affecting threadability. Increased bond strength achieved owing to the large surface area of ribs. Continuous thread enables retensioning in the event of ‘scaling’, as well as cutting of the bar at any point.
ADVANTAGES
No reduction in load capabilities as threads exceed the nominal bar diameter
Robust thread design accepts harsh conditions without affecting threadability
Increased bond strength achieved owing to large surface area of ribs
Continuous thread enables retensioning in the event of ‘scaling’, as well as cutting of the bar at any point
Thread profile offers excellent mixing capabilities in resins installation
Thread profile is ideally suited to hot-dipped galvanising, whilst maintaining threadability of the system.
ANCHOR HEAD APPLICATIONS
A wide choice of components offer a variety of anchor head designs to suit installation requirements.
SPECIFICATIONS
Steel grade | Nominal diameter (mm) | Nominal cross sectional area (mm2) | Max. diameter over ribs (mm | Min. yield load (kN) |
In accordance with SABS 920 1985 | 16 | 201 | 18.0 | 100 |
20 | 314 | 22.5 | 152 | |
25 | 491 | 28.0 | 245 |
INSTALLATION HARDWARE
A range of hardware to accommodate spinning and tensioning activities in Thread Bar 500 installation is offered. The following stock items are available:
TB 500-TENSIONER – Adaptor unit enabling tensioning of anchor nut by means of jackhammer. Socket head accommodates the anchor nut and the hexagon drive-shaft suits the jackhammer
TB 500-SPINNER – Adaptor unit enabling spinning of bar for resin installations
TB 500 ‘T’ SPANNER – Manual tensioning unit with extended socket head allowing easy access to the workplace. Provides tensioning capabilities in areas where jackhammer availability and time is limited.
MECHANICAL ANCHORING
Expansion shells provide an efficient and simple means of point anchoring in hard rock conditions. Available in a range of sizes to accommodate borehole diameters used in the industry.
Expansion shells offer the following advantages:
Application is simple and widely accepted
Reliable anchoring is achievable in dry and wet boreholes
Spring-loading the expansion shell prevents any slippage when tensioning anchor head
Cementitious grouting by means of pumping over the bar or shot capsules, makes the installation permanent following the setting thereof.
RESIN ANCHORING
The relationship between borehole, capsule and bar diameters is critical in ensuring efficient and correctly installed bars. Correct installation will result in an anchor which offers the following advantages:
Excellent bond between resin, bar and borehole
Early load-bearing capabilities
Upgrading of rock strength surrounding the borehole owing to resin penetration
High level of corrosion protection.
The ribbed profile and coarse thread of the Thread Bar 500 provides excellent mixing capabilities when spinning through resin capsules. This can be further enhanced by deforming the leading end of the bolt into a ‘kinked’ profile as shown.
RECOMMENDED CEMENT CAPSULE DIAMETERS
TB 500 diam. (mm) | Borehole diameter (mm) | |||||
28mm | 30mm | 32mm | 36mm | 38mm | 40mm | |
16 | 25 | 25 | 28 | 32 | – | – |
20 | – | 25 | 25 | 28 | 32 | – |
25 | – | – | – | 25 | 28 | 32 |