ABSTRACT
Dolomite and limestone are two most widely quarried carbonate aggregates in the State of Illinois available for use as pavement materials. In particular, dolomites are believed to have mineralogical compositions that can provide improved durability and functionality for certain pavement applications requiring better quality materials. This paper presents two case studies where dolomitic aggregates were utilized in closely-monitored field test sections and showed superior performance when compared to limestone aggregates. The first section is for dolomitic aggregate Quarry By-products (QB) used as cement-stabilized base/subbase in low to medium volume roads, while the second case is for dolomite used as an unbound material for a gravel (unsurfaced) road application. The performances of pavement sections with dolomite aggregate and their durability aspects are compared to those of limestone sections. Preliminary findings indicate that dolomitic fines contributed to improved durability and/or higher strength gain due to delayed reactions associated with carbonate cementation governed by ‘dissolution precipitation’ reactions when exposed to temperature and moisture changes induced by freeze-thaw cycles.
