The wheel loads of heavy trucks contribute to various forms of pavement distress. Of the various types of damage, fatigue and permanent deformation are of great importance and are the primary focus of this study. Under NCHRP Project 1-25(1), the mechanics of truck-pavement interaction were studied to identify relationships between truck properties and damage. All heavy trucks, however, do not cause equal damage because of differences in wheel loads, number and location of axles, types of suspensions and the pavement, operating conditions, and environmental factors. Computer models were used to generate representative wheel load histories characteristic of the different trucks and operating conditions. Rigid amd flexible pavement structural models were used to obtain pavement "influence functions", which characterize the pavement response to tire loads at any location on the roadway. The pavement responses arising from the combined loads from all wheels of a truck were then evaluated to estimate overall pavement damage caused by each truck. The study assessed the significance of truck, tire, pavement, and environmental factors as determinants of pavement damage. Although most of the findings reinforce the existing understanding of pavement damage from heavy-truck loads, the treatment in this study provides a systematic overview of the interactions, as well as new insights on the mechanics involved. It is interesting to examine the findings from the perspective of the truck characteristics that affect pavement damage, and the pavement and environmental factors that influence sensitivity to truck wheel loads.
Samenvatting