The viability of a cement-emulsion treated calcrete gravel base in comparison with a crushed stone base

In many world regions good quality roadbuilding materials are scarce. The paper discusses the evaluation of the performance of a G4 (1) cement-emulsion treated calcrete gravel base in comparison with a G2 crushed stone base in Botswana. A 2,2 km section of the road was constructed using the G4 cement-emulsion treated calcrete gravel or better known as an Emulsion Treated Base (ETB). The balance of the road under the same contract, used a wellgraded crushed stone G2 base (i.e. the second highest quality unbound base). A G2 base is invariably always constructed on top of a cement-treated subbase. Falling Weight Deflectometer (FWD) evaluation of both road sections showed that in this particular case the cement-emulsion treated gravel base performed better than the G2 crushed stone base. To verify this finding cores were drilled from the calcrete ETB section of the road and evaluated by means of the Unconfined Compressive Strength (UCS) tests. One core was also evaluated with the K-mould test. This test substantiated the FWD findings. The use of cement-emulsion treated bases is therefore a viable option to consider for the rehabilitation or upgrading of the pavements of roads through deep in situ recycling. More importantly, the results also confirm that in regions where good quality roadbuilding materials are scarce or prohibitively expensive, it is possible to construct new roads optimally through this technique, which already has a proven track record in southern Africa.

Language

  • English

Media Info

  • Pagination: 16p
  • Monograph Title: First International Symposium on Subgrade Stabilisation and In Situ Pavement Recycling Using Cement, Salamanca, Spain, 1-4 October 2001

Subject/Index Terms

Filing Info

  • Accession Number: 01392484
  • Record Type: Publication
  • Source Agency: ARRB
  • ISBN: 8489875278
  • Files: ATRI
  • Created Date: Aug 23 2012 7:10AM