HMA Compaction

It has been said that the top three factors in real estate are “location, location, location”. It can also be said that the top three factors in HMA pavement construction are “compaction, compaction, compaction”. Compaction is the process by which the volume of air in an HMA mixture is reduced by using external forces to reorient the constituent aggregate particles into a more closely spaced arrangement. This reduction of air volume in a mixture produces a corresponding increase in HMA unit weight, or density (Roberts et al., 1996[1]). Numerous researchers have stated that compaction is the greatest determining factor in dense graded pavement performance (Scherocman and Martenson, 1984[2]; Scherocman, 1984[3]; Geller, 1984[4]; Brown, 1984[5]; Bell et. al., 1984[6]; Hughes, 1984[7]; Hughes, 1989[8]). Inadequate compaction results in a pavement with decreased stiffness, reduced fatigue life, accelerated aging/decreased durability, rutting, raveling, and moisture damage (Hughes, 1984[7]; Hughes, 1989[8]).



Footnotes    (↵ returns to text)
  1. Roberts, F.L., Kandhal, P.S., Brown, E.R., Lee, D.Y., and Kennedy, T.W.  (1996).  Hot Mix Asphalt Materials, Mixture Design, and Construction.  National Asphalt Paving Association Education Foundation.  Lanham, MD.↵
  2. Scherocman, J.A. and Martenson, E.D.  (1984).  Placement of Asphalt Concrete Mixtures.  Placement and Compaction of Asphalt Mixtures, F.T. Wagner, Ed.  ASTM Special Technical Publication 829.  American Society for Testing and Materials.  Philadelphia, PA.  pp. 3-27.↵
  3. Scherocman, J.A.  (1984, March).  Guidelines for Compacting Asphalt Concrete Pavement.  Better Roads, Vol. 54, No. 3.  pp. 12-17.↵
  4. Geller, M.  (1984).  “Compaction Equipment for Asphalt Mixtures.”  Placement and Compaction of Asphalt Mixtures, F.T. Wagner, Ed.  ASTM Special Technical Publication 829.  American Society for Testing and Materials.  Philadelphia, PA.  pp. 28-47.↵
  5. Brown, E.R.  (1984).  Experiences of Corps of Engineers in Compaction of Hot Asphalt Mixtures.  Placement and Compaction of Asphalt Mixtures, F.T. Wagner, Ed. ASTM Special Technical Publication 829.  American Society for Testing and Materials.  Philadelphia, PA.  pp. 67-79.  ↵
  6. Bell, C.A.; Hicks, R.G. and Wilson, J.E.  (1984).  Effect of Percent Compaction on Asphalt Mixture Life.  Placement and Compaction of Asphalt Mixtures, F.T. Wagner, Ed.  ASTM Special Technical Publication 829.  American Society for Testing and Materials.  Philadelphia, PA.  pp. 107-130.↵
  7. Hughes, C.S.  (October 1984).  “Importance of Asphalt Compaction.”  Better Roads, Vol. 54, No. 10.  pp. 22-24.↵
  8. Hughes, C.S.  (1989).  National Cooperative Highway Research Program Synthesis of Highway Practice 152: Compaction of Asphalt Pavement.  Transportation Research Board, National Research Council.  Washington, D.C.↵