RELATIONS BETWEEN PLACEMENT TECHNOLOGY AND SKIDDING RESISTANCE

ZUSAMMENHAENGE ZWISCHEN EINBAUTECHNIK UND GRIFFIGKEIT

IT HAS BEEN OBSERVED DURING THE LAYING OF SURFACINGS OF ASPHALTIC CONCRETE THAT DIFFERENT LAYING CONDITIONS PRODUCE VARIABLE SURFACE STRUCTURES, INDEPENDENT OF THE TYPE OF MIXTURE. A STUDY IS TO BE MADE TO DETERMINE WHICH OF THE POSSIBLE INFLUENCES HAVE A PARTICULAR EFFECT ON THE STRUCTURE OF THE SURFACE. COMMERCIAL LAYING EQUIPMENT IS TO BE USED TO KEEP THE LARGE NUMBER OF POSSIBLE VARIATIONS IN LINE WITH PRACTICE HITHERTO. SURFACE STRUCTURE IS ESTABLISHED BOTH BY THE LAYING EQUIPMENT AND BY SUBSEQUENT ROLLING. MOST OF THE LAYING MACHINES HAVE AN IMPACT BEAM WITH VARIABLE VIBRATION FREQUENCY. THE VARIABLE PLACEMENT CONDITIONS ARE TO BE EXAMINED FOR TAMPERS WITH HIGH AND LOW IMPACT FREQUENCY, SCREEDS WITH HIGH AND LOW FREQUENCY, VIBRATING ROLLERS WITH AND WITHOUT SIMULTANEOUS USE OF RUBBER TYRED ROLLERS, AND SMOOTH-WHEELED AND RUBBER TYRED ROLLERS. COMPACTION IN FRONT OF AND BEHIND THIS EQUIPMENT IS TO BE DETERMINED ELECTRONICALLY, AND TEMPERATURES ON THE SURFACE ARE TO BE MEASURED; THE STUTTGART FRICTION METER IS TO BE USED FOR SKIDDING RESISTANCE MEASUREMENTS.