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The objectives of the research reported are to (a) define the material properties of central plant recycled mixes in Texas, (b) compare properties of these recycled mixes with conventional paving mixtures normally used in Texas, (c) evaluate the performance of the pavements containing central plant recycled mixes, and (d) compare performance of pavements constructed with recycled and conventional paving mixtures. Hveem, Marshall, resilient modulus, indirect tensile, direct tensile, and water sensitivity properties are reported for the recycled mixtures compacted both in the laboratory and under normal field procedures. Bituminous mixtures investigated include recycled asphalt concrete and recycled portland cement concrete. Performance is reported in terms of serviceability index as measured by a ride meter and by the use of a visual condition survey. The results of this study indicate that suitable bituminous mixtures can be produced by central plant recycling operations. Performance of pavements containing recycled mixtures appears to be suitable.

The authors discuss test results and analyses of tire hydroplaning, skid resistance, and other tire-pavement interactions. They address roadway and vehicle operator controls for mitigating hydroplaning and improving highway safety. The conclusions are based on analyses of simulation, laboratory, and full-scale tests. Pavement cross slope, texture, rut depth, pavement wear, surface drainage, drainage-path length, precipitation intensity and duration, tire inflation, tread-pattern depth, tire construction, and vehicle traveling speed influence hydroplaning tendencies and vehicle control. Other factors considered are tire rolling resistance, vehicle fuel consumption, noise, splash and spray, and headlight glare. These results are applicable to highway pavement design, construction, and rehabilitation; tire construction; and vehicle operation.