Mat Shoving

Description

Displacement of the HMA mixture in a longitudinal direction while compacting. Shoving under traffic loading is covered in a seperate article.

Problem

Mats that shove under compaction loading are generally unstable and are likely to continue to deform under traffic loading leading to roughness problems. If a mat is not adequately compacted because it is shoving, the resulting low density can cause the mat to be susceptible to decreased stiffness, reduced fatigue life, accelerated aging/decreased durability, rutting, raveling, and moisture damage (Hughes, 1984[1]; Hughes, 1989[2]).

Possible Causes

Tender mixes.

Solutions

Eliminate the causes for tender mixes or develop a compaction sequence and pattern to accommodate the tender mix. Compaction sequence and patterns will depend upon the type of mix tenderness.



Footnotes    (↵ returns to text)
  1. Hughes, C.S.  (October 1984).  “Importance of Asphalt Compaction.”  Better Roads, Vol. 54, No. 10.  pp. 22-24.
  2. 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.