First epoxy coated strand job for dam contruction in the US

Installation of Flo-Bond epoxy coated strand anchors at the Steward Mountain Dam

The double curvature thin arch concrete structure was built in the 1920's and is approximately 64 m high. Retrofitting became necessary to prevent a possible failure of the arch section, in which a separation along the joints during a major seismic event would occur.

That was a very real danger, as, during construction, the concrete cold joints had not been properly cleaned of laitance, resulting in weak joints with little or no cohesion between pour sections. The solution was to stabilize the dam by installing sixty-two 22x0.62" DYWIDAG Rock Anchors in the arch section to restore monolithic action.

A further 22 anchors were installed in the left thrust block to provide for enhanced stability against sliding. As the anchors were to be stressed and remain ungrouted for a 100 days monitoring period, protecting the strands against corrosion became an extremely important consideration. The superior corrosion protection and high bond capacity of the Flo-Bond epoxy coated strand provided the ideal solution for both requirements.