Grout Mix Development For Bedrock Grouting at Dale Hollow Dam

The U.S. Army Corps of Engineers designed a bedrock grouting program for Dale Hollow Dam in Celina, Tennessee, and contracted with Rembco Geotechnical Contractors, Inc., to perform the work. The design required a suite of grout mixes exhibiting excellent stability, low bleed, and low pressure filtration over a wide range of viscosities. The contractor spent significant time developing six different mix formulations for the project. The primary focus of this effort was to meet the specified performance requirements using a single water to cement (W:C) ratio for the grout mixes. The use of a single W:C ratio was critical in being able to swiftly change the batches from one mix design to another while minimizing wasted grout and simplifying field quality control. This paper describes some of the complexities and considerations in this grout mix development process.