5.1 Viscosity is a fundamental characteristic for slurries in construction applications. The Marsh Funnel Viscosity test can be used for field quality control of slurries. Relative changes in slurry viscosity can be identified using Marsh Funnel measurements and modifications can be made to mixing and handling procedures.

Note 1: The development of the Marsh Funnel is credited to Hallan N. Marsh of Los Angeles who published the design and use of his funnel viscometer in 1931.

5.2 This test method allows for the assessment of the apparent viscosity of construction slurries in the laboratory and in the field. The Marsh Funnel Viscosity is not a true viscosity, it is an index value and can only be used to assess the relative viscosity of the slurry to water. Higher MFV values are obtained for slurries with higher viscosity and lower MFV values are obtained for slurries with lower viscosity.

5.3 In this test, it is assumed that the apparent viscosity of a slurry is directly related to the flow duration through a specially shaped funnel (the Marsh Funnel).

5.4 In slurry construction applications, the viscosity of a slurry must be maintained within a predetermined range to stabilize the surrounding soil being supported.

5.5 The Marsh Funnel Viscosity has been widely used in drilling soil and rock for water wells and oil, gas, soil stabilization, foundation drilling, and hydraulic barrier applications.

5.6 Inert suspended solids (such as fine sands, clays, and cement) and additives affect the viscosity of slurries. This test may be used to determine the relative effects of these and other such materials on the viscosity of a slurry.

Note 2: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing, sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.

1.1 This test method provides an indirect measurement of the viscosity of construction slurries using a funnel (Marsh Funnel) and a graduated cup with specific volume marks. This test method provides an indicator of the viscosity on a routine basis. This test method has been modified from the API Recommended Practice 13B-1.

1.2 The result determined using the method is referred to as the Marsh Funnel Viscosity. The Marsh Funnel Viscosity is an index property and is not an actual measurement of viscosity.

1.3 This test can be performed in the laboratory or in the field to assess the Marsh Funnel Viscosity of a slurry for quality control purposes.

1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.