Waddell, Joseph J.
Chief Materials Engineer, Knoerle, Graef, Bender, and Associates, Inc., Chicago, Ill.
Pages: 10 Published: Jan 1959
The Northern Illinois Toll Highway consists of 187 miles of four- and six-lane limited access tollway, providing a belt-line highway around Chicago. Branches extend to the Indiana line, to Wisconsin at Beloit and Kenosha, and west past Aurora. To provide adequate safety for the motorist, the road was designed with wide, asphaltic concrete shoulders on both sides (Fig. 1). These shoulders provide a safe space for disabled vehicles to stop off the main pavement. A total of 602,000 tons of hot plant-mixed bituminous concrete was required for the 3,664,000 sq yd of shoulder. The Marshall test method was used to design the asphaltic concrete and to control its proportioning, mixing and compaction. Because construction on some 50 individual contracts was to be administered by 23 different section engineers, this method was selected because it was considered to be capable of producing consistent results in the hands of many different operators and to lend itself to easy demonstration and explanation to persons unfamiliar with control of bituminous pavement. It was also felt that the method selected must have a satisfactory history of use and provide a satisfactory degree of control, yet be relatively simple in application.
Paper ID: STP47176S