Citation

Laganier R. Transp. Res. Rec. 1977; 624: 33-39.

Copyright

(Copyright © 1977, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Problems of safety are closely linked to the state of the wearing course. In view of the imperious necessity to insure the best tyre-road adhesion possible, the researches undertaken in this fiel by the Laboratories of the French Highways Administration have been directed towards the study of the reasons of rapid decreasing of friction which may lead to aquaplanning of the vehicles. The precise study of these friction coefficients on damp pavement must be accompanied by measurements of water film thickness which covers these pavements. These measurements are particularly difficult, for the surfacing of a pavement is not perfectly even at all scale. This paper describes a measurement method of the water film thickness which uses a device based on the principle of rapid neutron deceleration by hydrogen nuceli. This method is very advantageous for it allows to make a "point" measurement with respect to the whole pavement and to obtain a mean water film thickness which takes into account the pavement asperities. The research now goes towards the study of a simulation computer model. The data of output surfaces function are obtained on a miniature model in laboratory. The geometrical data are measured on the road. A car with a gyroscopic machine gives the gradient and the ruled surfaces of pavement (Scale of lie) treatment gives and automatical method to find water accumulation zones on an itinerary (highway principaly). The local investigation using gradient gradiation on the pavement (Scale of evenness and inferior, but superior to roughness) allows the river system of drainage the flashes of water and accumulation, to be simulated during any intensity storm.