Grout Pumping and Injection Operations TR 003 2.5. Marsh Flow Time – or Viscosity Test. This is also a quick and simple test that is conducted at the grouting site and measures the viscosity (fluidity) or flow time of the grout compared to water. The typical injection grouts will be designed to have Marsh flow times of between 29 – 36 seconds, compared to water which is 28 seconds. Thicker grouts range up to 40 seconds and greater, until the grout is so thick that it cannot run from the cone. A Marsh Flow Cone consists of a plastic cone of 1500ml capacity with a small outlet. There is also a plastic jug with graduations on it. The cone is filled with grout and the time for 1000ml to flow into the jug is recorded as the flow time or viscosity in seconds. The test is performed as follows: Mud Balance (density) Test Calibration check–first test with water to check calibration. Fill cup with clean water and place lid firmly onto cup. Dry off any excess water. Place balance knife edge on the base and measure density or specific gravity (S.G.) from the balance arm. Water should measure SG = 1.0 0.01 Adjust the lead shot in the shotwell to correct any error Test procedure: 1. Ensure cup is clean and dry. 2. Fill cup with fresh mixed grout until full. Place lid firmly onto cup with a turn to seal the lid. 3. Wipe away any excess grout 4. Place balance on the base and move the slide until the level bubble is centered. 5. Record the SG reading from the graduated beam Date/Shift _______/_______ Time sampled ____________ Grout mix/type _________________________ SG / Density ______ or ___________ kg/m3
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