Evaluation of Bituminous Mixes in Pavement Structures:Interim Report II. Characteristics of Rutting on High Quality Bituminous Highway Pavements.

摘要

Rutting of high quality flexible pavements was studied to determine the contribution of the asphalt bound paving materials to this type of failure. Sixteen test sites were selected on Interstate Highways 35and 40in Oklahoma. These pavement sections of various ages were constructed on four different types of base course materials. A profile apparatus was developed to plot the transverse profile of the pavement surface. Rut depths and surface humps outside the wheelpath locations were scaled from the profile tracings. Cores of the asphalt paving layers were obtained at selected points across the pavement and densities of the respective layers determined. Stereo-photography was used to obtain quantitative estimates of surface wear in the wheelpaths. From 8to 58percent of the total rut depths at the test sites was attributed to post construction densification of the asphalt bound layers. Evidence of laternal creep or instability in these layers was found at eleven of the sixteen sites and this factor contributed from 30to 78percent of the rut depths at these locations. Surface wear or attrition in the wheelpaths also contributed a significant amount to the depth of rut.