STP1562: Calcium Carbonate Content of Various Bentonites Used in GCLs

    Koerner, George R.
    Professor Emeritus, CQA, GSI, Folsom, PA

    Pages: 8    Published: Jul 2013


    A practical method is described to determine the carbonate content of the bentonites used in geosynthetic clay liners (GCLs). The determination of the carbonate content of bentonite uses a reactor wherein hydrochloric acid (HCl) is mixed with the bentonite specimen in a closed vessel. After activation, the reaction creates carbon dioxide (CO2) pressure proportional to the calcium carbonate (CaCO3) content of the sample. It has been suggested that the calcium carbonate content might be related to long-term performance insofar as cation exchange is concerned. In addition to determining the CaCO3 content of the various bentonites, long-term permeability tests were conducted on the same GCL specimens to illustrate this possibility.


    gcl, lab test, flux, permeability, durability

    Paper ID: STP156220120092

    Committee/Subcommittee: D35.04

    DOI: 10.1520/STP156220120092

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