Abstract:
Alabama Power partnered with Alden Research Laboratory in Holden, Massachusetts to design and construct a large-scale grout test chamber with a defined protocol to test the effectiveness of various High-Mobility and Low-Mobility grout mixes on a large scale. Test protocols utilize volumetric mixers and test chambers prepared to replicate a variety of site-specific subsurface conditions to provide more accurate testing than “ table-top” lab tests with more control/monitoring and less cost than in-situ site testing. The intended goal of the program was to evaluate grout mix designs to optimize cost and performance of future grouting projects. The test chamber consists of six modules, each module was three-foot-wide, three-foot-tall, and fivefoot-long for an overall length of 30 feet. The test chamber had a total volume capacity of 270 cubic feet. Modules have top, bottom, and side panels that disassemble granting access to examine the final cured sample. The first and last modules each contain one end panel. During the test process the chamber is filled with simulated geo-material and water. Grout is injected under pressure through an injection nozzle centered in the end panel of the first module. Water and grouts are displaced from the test chamber through discharge ports located on the top, bottom, and sides of each test chamber module. The volume and specific gravity of discharge flows were continuously measured from each module in real-time to determine discharge of displaced water and grout during the test. Grab-samples were taken at these discharge points to analyze cement-water separation and changing rheology of the initial grout mix. Pressure and temperature sensors were installed along the test chamber at various points to provide further insight into grout transport and dispersion behaviors. This paper will present the test results to-date and expand on the benefits it provides the Logan Martin Grouting Project. Keywords: Grout, Karst, Seepage, Research, Testing, Dam, Hydro, Alabama Power, Logan Martin, Alden