Six Stable Grout Mix Designs for Bedrock Grouting at Dale Hollow Dam

Rembco performed a bedrock grouting program, designed by the Army Corps of Engineers, at Dale Hollow Dam in Celina, TN. The design required a suite of grout mixes to be formulated exhibiting excellent stability, low bleed, and low pressure filtration over a wide range of viscosities. Rembco spent significant time in the laboratory to develop six (6) different mix formulations for use on the project. The primary focus of this effort was to meet the specified performance requirements using only a single water to cement (W:C) ratio for the most common five (5) grout mixes. The use of a single W:C ratio played a critical role in the ability to swiftly change the batches from one mix design to another while minimizing wasted grout and simplifying field quality controls. This paper will present the process used to develop a suite of stable grout mixes that could be interchanged seamlessly by the mix crew to rapidly respond to changes in the conductivity of each borehole during grouting.