Engineering Commons^™

Highway Skid Resistance, James H. Havens

Kentucky Transportation Center Research Report

The physics of friction and traction are reviewed. Hypotheses are presented. Use of a scanning electron microscope to detect and identify polishing aggregate is presented.

Size reduction (crushing) produces greater concentrations of sharp edges, reducing flat and plane surfaces not otherwise contributing to traction.

Surface permeability and drainage through macrotexture was evaluated by an air-percussive device. An air-efflux device was contrived for evaluating hydroplaning potential and for evaluating open-graded surface courses. In-filling has been observed where road debris is abundant.

Grippers and sharpness are needed for wet traction . Drainage is needed to lower hydroplaning potentials. Sand-sizes optimize the concentration …