Effects of heavy loading on Wisconsin's concrete pavements

Wisconsin Department of Transportation District 7 filed a Report of Early Distress for a 6.5-mi stretch of USH 8 and an 8-mi stretch of USH 51 near Rhinelander in 2001. An investigation of the causes for the premature failures concluded that overloaded logging trucks were a key factor leading to the premature failure of the doweled jointed plain concrete pavements (JPCPs). Consequently, a recommendation was made to develop design guidelines for heavy truck loading on concrete pavements in Wisconsin. To develop the guidelines, JPCP design guides were solicited from several agencies, specifically, agencies located in Federal Highway Administration (FHWA) Climate Regions III and VI. A review of the design guides indicated that the 1993 American Association of State Highway and Transportation Officials (AASHTO) guide and the Portland Cement Association method are the two most popular state-of-the-art methods that attempt to address overloading, either using load safety factors or probabilistic concepts such as reliability. The two methods were further evaluated in terms of their ability to provide a transition to the AASHTO 2002 mechanistic-empirical design and allow a range of rehabilitation options for old JPCP. Based on the evaluation, the 1993 AASHTO guide was recommended for consideration in the design of JPCP in Wisconsin. The 1993 AASHTO guide was evaluated using data from one logging truck corridor along USH 8. The results indicated that a high-end reliability combined with modified rigid equivalent single axle load (ESAL) factors has the greatest potential to address overloading on Wisconsin�s concrete pavements.