USING ADDITIVES TO IMPROVE COLD WEATHER COMPACTION

A laboratory investigation was conducted to determine possible methods of improving cold weather earthwork techniques and extending the construction season. Compaction tests, using standard and modified AASHO compactive effort, were conducted on a silty sand at temperatures of 68 and 19 F (20 and -7 C). The low- temperature tests of soil with 0, 2, and 3 percent calcium chloride were performed to study the influence of an additive on the moisture-density relationship of the test soil. Tests at 68 F (20 C) were used to establish a frame of reference for the low-temperature tests and to determine the normal compaction characteristics of the silty sand. To eliminate the effects of particle size, a single sized particle was prepared in the laboratory and indicate that (a) additives can be effectively used to offset the detrimental effect of low temperature on compaction; (b) soils compacted at 19 F(-7 C) and treated with 2 or 3 percent calcium chloride have essentially the same compaction characteristics as an untreated soil compacted at a temperature of 68 F (20 C); and (c) an untreated soil compacted at 19 F (-7 C) has significantly lower dry densities than a soil compacted at 68 F (20 C). The low densities that occur when a soil is compacted while frozen are due to the formation of ice within the pore spaces. Modeling the pore fluid as a solution of additive and water and using the concept of phase equilibria shows that the amount of additive required to prevent the formation of ice in a compacted soil is related to the freezing point depression characteristics of the additive. A discussion of field problems and application techniques is included to aid the practicing engineer in using the method suggested in the paper.

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 57-68
  • Monograph Title: Stabilization
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00134000
  • Record Type: Publication
  • ISBN: 0309024706
  • Files: TRIS, TRB
  • Created Date: Jul 22 1976 12:00AM