EFFECT OF DRYING TEMPERATURE ON THE INDEX PROPERTIES OF CALCRETES

Atterberg limits, shrinkage factors, and other properties of calcrete soil fines determined after drying at 150 deg C were campared with the results of similar tests carried out on air-dried materials and showed significant decreases in liquid limits and in plasticity indexes by up to 4 percentage points. The maximum decrease in any particular case is predictable. Bar linear shrinkage was affected relatively little. The effects caused by drying at 50 deg C were generally more subdued and erratic, but more tests are required to determine whether drying at the lower temperature offers any advantage. These phenomena are chiefly ascribed to the presence of the clay mineral palygorskite, which is common in calcretes and other soils of the arid and semiarid zones. The contribution of wetting and drying cycles to a further decrease in liquid limit, plasticity index, and bar linear shrinkage is ascribed to cementation effects. The effects found provide a partial explanation of the good performance of apparently substandard calcrete roads. The practical significance of such effects can be minimized by standardization of drying procedures, which must be the same both in deriving specifications and in quality control. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 24-32
  • Monograph Title: Moisture and frost-related soil properties
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00193797
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: May 11 1979 12:00AM