David F. Rogge

DESIGN, CONSTRUCTION, AND MAINTENANCE GUIDELINES FOR POROUS ASPHALT PAVEMENTS

Oregon has been using open-graded hot mix on its roadway system since the late 1970s. Because of the performance of these early jobs (and the continued good performance of these mixes), open-graded hot mix has been the preferred choice for a surface course on Oregon highways. The following are described with respect to the use of these mixes in Oregon: historical perspective; design, including mix and structural design; construction, including quality control/quality assurance considerations; and maintenance and rehabilitation practices with porous pavements. The continued success of the use of these materials from both a performance and a public acceptance standpoint indicates they will be the pavement of choice in Oregon for the foreseeable future.

HOT IN-PLACE RECYCLING OF ASPHALT PAVEMENTS: OREGON EXPERIENCE

A study was carried out to evaluate the potential of using hot in-place recycling (HIR) as a rehabilitation alternative in Oregon. Data from six Oregon Department of Transportation HIR projects constructed in 1992-1993 were analyzed. The construction equipment, pavement properties, project selection, mix design, and resulting performance are summarized and presented. Only one HIR project was successful in rejuvenating the pavement and restoring ride quality. Of particular interest are the problems encountered in the other projects, which are discussed and show the importance of preliminary engineering and project selection for successful HIR. The lessons learned from the six projects are used as guidelines for selecting suitable candidate pavements for HIR. The results from the HIR projects combined with a literature review and limited laboratory testing led to a recommended HIR mix design procedure. Significant findings include the following: (a) HIR is a developing technology that shows promise for properly selected projects, (b) project selection is the most critical step in the HIR process, and (c) critical mix design inputs come from testing in situ pavement properties and laboratory specimens remolded with rejuvenating agent added.

Determining Standard Cost Estimating Methods for Negotiating Engineering and Related Services Contracts

The Oregon Department of Transportation (ODOT) was interested in standardizing methodology for estimating costs of engineering and related services for purposes of negotiating contracts for those services. To accomplish this objective, current ODOT procedures, as well as those of other transportation agencies were studied. Recommended best practices were generally consistent across ODOT and other transportation agencies, so the emphasis of the research became documenting those procedures and compiling databases to aid in the estimating process. Two databases of ODOT projects were compiled. Databases include estimated consultant hours by tasks and descriptive information, such as project type, number of nonstandard drawings, total project cost, number of subconsultants, etc. The databases were analyzed to identify relationships between project characteristics and consultant contract hours required. Results of these analyses are presented. A procedure for use of the databases was developed. This paper summarizes the results of the research.