Impact of Heavy Vehicles on Pavement Responses

Abstract

The South Dakota Department of Transportation (SDDOT) is currently faced with the issue of allowing heavy construction and agricultural equipment to use public highways. These equipment include the following: road scrapers, grain cart, and Terragator (i.e. fertilizers). All of these equipment carry heavy loads in the order of 100–200 kN per single axle. The majority of these vehicles also use lugged tires with a highly non-uniform contact area at the tire-pavement interface. In order to assess the equivalent damage that such vehicles impose on highway pavements, the SDDOT initiated a study to measure the response of field pavement sections under the loading conditions of heavy construction and agricultural equipment. The experiment measured the responses of six pavement sections in South Dakota to the loading conditions of ten combinations of vehicles and axle loads. The measured pavement responses included: strains, stresses, and deflections. The analysis of field measurements of flexible pavement responses under the scraper, grain cart, and Terragators showed that most of these vehicles are more damaging than the 80-kN single axle loads. It was recommended that SDDOT limits the use of such equipment on flexible pavements to reduce their impact on the overall performance of such pavements.