An Evaluation of the Roto-Mill Profiler on Concrete Pavements in Iowa, MLR-76-1, 1976

A new machine, the ROTO-MILL Profiler, became available in early 1976. This machine, manufactured by CMI Corporation of Oklahoma City, Oklahoma provides pavement surface Scarification at a much higher production rate than was previously possible. Iowa had the opportunity to observe and evaluate this machine on two separate sections of primary portland cement concrete pavement in October, 1976. The marked improvement in the profile index and the skid resistance indicates this machine may be considered a viable method for improving rideability and skid resistance of a roadway that is otherwise reasonably sound.

Maintenance of Pavement Skid Resistance (Open Graded Asphalt Friction Courses), Progress Report, HR-170, 1976

This project involved the evaluation of several aggregates previously rated poor to excellent with respect to skid resistance and certain mix design parameters. An open graded asphalt friction course was evaluated using 4 comparably graded aggregates: quartzite, fine grained limestone, coarse limestone and lightweight expanded shale. The performance investigations involved the verification of observations of the quartzite test sections, evaluation of the effect of blending the superior quartzite with a typical coarse grained-textured limestone, and the evaluation of the limestone. The effects of traffic on the aggregates used in the test sections were studied, as well as the relationship between asphalt content levels and traffic with respect to performance. The bond of the open graded friction course mixture was also evaluated. The SN performance of all test sections after sixteen months of exposure was found to be satisfactory in that none of the material combinations had polished to the point where unacceptable SN levels developed. When material combinations were compared, significant differences were noted.

Road Map Math, 1976

Road Map Math is an instructional program for low-achieving students in grades four to twelve. It is helpful in teaching language arts, place geography, map reading and mathematics. This booklet was made in conjunction with Department of Public Instruction, Price Laboratory School at the University of Northern Iowa and the Planning and Research Division of the Iowa Department of Transportation.