Chip Seal Construction Variability and Its Impact on Performance

Abstract

This paper presents findings obtained from field and laboratory tests that were designed to assess chip seal construction variability in comparison to the targeted design, and to investigate the impact of any variability on the performance of chip seal treatments. The research approach involved three double-seal pavements in North Carolina. Granite 78M and No. 14 aggregate and CRS-2L emulsion were used in the construction. Chip seal specimens were sampled from each of the three test sections, and the aggregate application rate (AAR) and emulsion application rate (EAR) were determined using ignition oven tests. Chip seal performance was evaluated in terms of aggregate loss and bleeding using a third-scale model mobile load simulator (MMLS3). In addition, the fresh emulsions used in the test sections and the residue were tested using a rotational viscometer and dynamic shear rheometer, respectively. The construction variability reflected in the AARs and EARs and the emulsion residue properties were used to describe the aggregate loss and bleeding performance as determined by the MMLS3.