On April 25th detailed notes wore made on each station of this project, and it was decided that samples should be taken to represent each type of surface on the project. Seventeen samples ware selected as representative of the different types of mixes, and on May 6th and 7th samples fifteen inches in diameter were drilled from this project. These samples were selected to represent the variations in gradings and bitumen content.
Digital Object Identifier
Kentucky Highway Materials Research Laboratory, "Bituminous Construction with Sandstone Aggregate Johnson County Project" (1943). Kentucky Transportation Center Research Report. 1378.