California Department of Transportation

Slurry/Micro-Surface Mix Design Procedure

Pooled Fund Project: RE-0211-01; SPR-3(073)

Research Problem Statement

There is a need to develop new mix design procedures, guidelines and specifications for slurry seal and micro-surfacing that address performance needs of the owners and users, design and application needs of the suppliers, and improve the reproducibility of the designs. The current ISSA procedures for Slurry Seal Mix Design (A105) and Micro-surfacing (A143); and Practices for Design, Testing and Construction of Slurry Seal (ASTM D3910-98) and Practice for Design, Testing and Construction of Micro-surfacing (ASTM D6372-99) have their origins in the 1980's before the wide-spread use of micro-surfacing and the use of polymer modified emulsions in slurry seals. These test methods and design procedures are being used because of the lack of a test method or mix design procedure that specifically addresses micro-surfacing and the adequate representation/characterization of its performance indicators. Recent Texas Transportation Institute studies documented the problems associated with using the existing methods of micro-surfacing and suggested the development of comprehensive mix design and analysis procedures. While differences exist between slurry seal and micro-surfacing applications (i.e. traffic volume, application thickness and curing mechanisms), the similarities of the tests currently used indicate that the two systems must be studied together.