System Description

THREADBAR^® Anchors

The DYWIDAG THREADBAR^® Rock and Soil Anchor System is manufactured in the United States and Canada exclusively by DYWIDAG-Systems International.

Simple and Rugged

The THREADBAR^® has a continuous rolled-in pattern of deformations along its entire length which allows anchorage hardware or couplers to thread onto the bar at any point. The coarse thread is almost indestructible under normal jobsite conditions.

High Bond Strength

The deformation pattern provides excellent bond between the bar and cement grout, allowing a reliable transfer from the anchor prestress load into the grout without the need for additional mechanical devices. The narrow spacing of the deformations assures close crack spacing in the surrounding grout and therefore, the smaller crack width will not degrade the corrosion protection.

Positive Anchorage

The bar is anchored using a threaded nut, which, unlike a wedge type anchorage, is not liable to slip when the anchor force is reduced due to possible ground movements. In addition, the threaded nut anchorage has a known overload capacity, which cannot be duplicated, by a wedge type anchorage without the utilization of elaborate and expensive details.

Removable

The THREADBAR^® can be removed after destressing the anchor by unscrewing the unbonded portion of the bar from a coupler or out of an embedded end anchorage. Bars with end anchors and sleeved within the bond length can be completely removed. This is especially important where temporary anchors are installed below adjacent properties and must be removed after use.

Easy to Stress

The reliable and compact threaded nut anchorage has almost no anchor set. Its hemispherical shape easily accommodates the small angular misalignments between bar and anchorage due to construction tolerances. Lightweight, durable equipment makes stressing, restressing and adjusting the anchor load up or down easy to do.

Easy to Install

Because of their inherent stiffness and ruggedness, THREADBAR^® Anchors can be easily installed in any position, including upward. It is particularly easy to install a bar in a pre-grouted hole.

Easy to Check Actual Prestress Load and Restress

The threaded design makes it possible to make a lift off test or to adjust the anchor load at any time during the service life of the anchor. Corrosion protection can be maintained at all times.

Unprotected Anchors

Unprotected anchors are used for temporary applications. The free stressing length is unprotected while the bond length is embedded in the cement grout body. Unprotected anchors may be subject to corrosion. However, the relatively large diameter and solid cross-section of the DYWIDAG THREADBAR^® offers more corrosion resistance than smaller diameter high strength, prestressing steel elements with a larger surface area.

Insurance Against Anchor Failure

In cohesive and other poor soils, a proven and reliable DSI Post-grouting System can be used to increase the capacity of an anchor. The use of this system can make the difference between an anchor that works and one that does not.

Easy to Splice

The continuous thread makes it possible to extend the THREADBAR^® to any length, simplifying transportation and installation. Extending the bar beyond the stressing end to connect to another structural member is also a simple operation.

Corrosion Protection Options

A wide variety of internal corrosion protection options are available to choose from depending upon the expected length of service and the aggressiveness of the Environment.