You are being redirected because this document is part of your ASTM Compass® subscription.
    This document is part of your ASTM Compass® subscription.

    Volume 46, Issue 4 (May 2018)

    Special Issue Paper

    Guidance for Investigating Calcite Precipitation by Urea Hydrolysis for Geomaterials

    (Received 25 February 2017; accepted 5 March 2018)

    Published Online: 08 May 2018

    CODEN: JTEVAB

      Format Pages Price  
    PDF (722.96 KB) 12 $25   ADD TO CART

    Cite this document

    X Add email address send
    X
      .RIS For RefWorks, EndNote, ProCite, Reference Manager, Zoteo, and many others.   .DOCX For Microsoft Word



    Abstract

    Microbially induced calcite precipitation (MICP) is a sustainable method of stabilizing (i.e., cementing) loose sandy deposits or creating an impervious barrier within the soil mass or both. MICP can occur through various biochemical pathways, and ‘Urea Hydrolysis’ (UH) is considered to be the most efficient of the MICP methods for biochemically inducing calcite precipitation. To date, the geotechnical engineering community that has investigated MICP has tended to focus on the hydromechanical behavior of the end product, i.e., MICP cemented sands; however, many biochemical factors that affect reaction-rate kinetics and MICP outcomes have been understudied or neglected. This study investigates the kinetics of UH and compares different sources of the urease enzyme—those microbially cultivated in the laboratory (i.e., Sporosarcina pasteurii) and those extracted from plants (i.e., Jack bean meal)—to investigate the influence of urea concentration, buffer capacity, and the cell harvesting method on UH. Through this study, an attempt has been made to arrive at an optimal concentration of urea, under the influence of the previously mentioned parameters and the buffering action of the soil, on urea hydrolysis. These results have implications for optimizing MICP and, in particular, for upscaling these methods to in situ applications.

    Author Information:

    Shashank, B. S.
    Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai

    Minto, James M.
    Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XJ,

    Singh, Devendra Narain
    Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, Powai

    Mountassir, Gráinne El
    Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XJ,

    Knapp, Charles W.
    Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XJ,


    Stock #: JTE20170122

    ISSN:0090-3973

    DOI: 10.1520/JTE20170122

    Author
    Title Guidance for Investigating Calcite Precipitation by Urea Hydrolysis for Geomaterials
    Symposium ,
    Committee D18