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
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