THE WHEATLEY BY-PASS EXPERIMENT ON ROAD BASES: SELECTION OF MIX PROPORTIONS FOR CEMENTED BASES CONTAINING AGGREGATE OF 3/4-INCH SIZE AND LARGER

The selection is described of mix proportions for use in coarsely graded cemented bases, in an experiment which was designed to investigate the influence on performance of changes in type of base. The study included bases with cement, bitumen and tar binders in different quantities in gravel and crushed stone aggregates covering a wide range of gradings. The mix proportions were selected on the basis of pilot-scale compaction trials conducted with the type of vibrating roller specified for the experiment. Moisture contents of 7.5 and 8 percent were adopted and the cement contents were adjusted to give the target strengths required by the experiment. The as-raised sandy gravel used presented difficulties. The results of tests did not warrant departure from the standard methods of curing concrete. Pilot-scale trials in which the base materials were compacted in two 4-inch thick layers in place of one 8-inch layer indicated that no significant increase in dry density could be obtained by this technique either with the same or with reduced moisture content and that 2-layer compaction introduced a risk of forming a weak plane along which the base would readily crack. Trials also indicated that the best method to introduce a layer of reinforcement was to compact a layer of base material 5 inches thick, lay the reinforcement, and then spread and compact a further layer to the total thickness of 8 inches.

  • Corporate Authors:

    Great Britain Police Research, Services Branch

    Horseferry House, Dean Ryle Street
    London,   England 
  • Publication Date: 1965-9

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Filing Info

  • Accession Number: 00083782
  • Record Type: Publication
  • Report/Paper Numbers: # LN/826
  • Files: TRIS
  • Created Date: May 29 1975 12:00AM