OVERVIEW OF PAY-ADJUSTMENT FACTORS FOR ASPHALT CONCRETE MIXTURES

In the fall of 1979, the Oregon State Highway Division and Oregon State University, with participation from the University of Washington, initiated a research project to study the impact of variations in material properties on asphalt pavement life. The study is aimed at developing a rational approach to assessing the effects of variations from specification limits so that a firm basis can be established for the development of pay factors. To collect information on the status of quality-control procedures and the use of pay-adjustment factors, a questionnaire was distributed to all state agencies, the District of Columbia, and the Federal Highway Administration. Each agency was asked to respond to questions on their current method for acceptance or rejection of asphalt concrete paving materials and related pay-adjustment factors. The results of the questionnaire are summarized. Analysis of the results indicates the following: (a) Most state agencies will accept one or more property characteristics of asphalt concrete that are outside specification tolerances, (b) most state agencies apply a pay-adjustment factor to accepted materials that are outside specification tolerances, (c) only 26 percent of the state agencies consider their pay factors to be proportional to reduced pavement serviceability, (d) approximately half of the agencies consider pay-factor plans to be effective in encouraging compliance with specifications, and (e) there is a wide disparity in the pay-adjustment factors used by the different agencies. (Authors)