Norwalk Motor Speedway in Norwalk, Ohio, recently made some concrete changes to their track. The track added a microsilica-modified concrete burn pad and 405 feet of fast-track concrete pavement to the starting areas of each of thier two racing lanes. Bill Bader, owner of the raceway, added 253 yards of concrete pavement to extend the starting line area. The new pavement is eight inches thick, 15 feet wide, and 405 feet long in each lane. In addition to the extensions to the starting lines, the tire burn areas were replaced using microsilica-modified concrete (MSC). The MSC was used to gain greater abrasion resistance. The concrete was supplied by Wm. Dauch Concrete, Norwalk, using Ohio Dept. of Transportation mixes. A moderate set mix was used for the starting line extensions. The microsilica-modified concrete used for the tire burn areas is the ODOT mix for overlaying bridge decks except the microsilica content was increased from 10% to 15%. Admixtures, including the microsilica additive, were furnished by W. R. Grace & Co.