EFFECT OF ADMIXTURES TO MORTAR AND COARSE AGGREGATES ON THE SKIDDING RESISTANCE OF CONCRETE SURFACINGS SUBJECTED TO VARIABLE MECHANICAL STRESS

UNTERSUCHUNGEN UEBER DEN EINFLUSS DER ZUSCHLAEGE IM MOERTEL- UND GROBKORNBEREICH AUF DIE GRIFFIGKEIT VON BETONOBERFLAECHEN BEI UNTERSCHIEDLICHER MECHANISCHER BEANSPRUCHUNG (POLIERBARKEIT)

IN RECENT YEARS THE SKIDDING RESISTANCE OF ROAD SURFACES HAS BEEN DETERMINED MUCH MORE BY THE WEAR CAUSED BY STUDDED TYRES THAN BY THE POLISHING OF THE AGGREGATES USED IN THE SURFACINGS. AFTER THE PROHIBITION OF STUDDED TYRES, IN THE NEXT FEW YEARS THE POLISHING OF AGGREGATES WILL BE A FAR GREATER FACTOR IN DETERMINING SURFACE ROUGHNESS, EVEN FOR CONCRETE ROADS. THE POLISHING OF AGGREGATES DEPENDS ON THEIR MINERAL COMPOSITION. IT IS INTENDED TO MANUFACTURE SAMPLES OF CONCRETE MADE WITH VARIOUS POLISHING-RESISTANT AGGREGATES OF DIFFERENT TOUGHNESS, AND TO TEST THEM BEFORE AND AFTER THEY ARE SUBJECTED TO VARIOUS MECHANICAL STRESSES FOR MODIFICATION TO SURFACE PROPERTIES AND SKIDDING RESISTANCE. IN ASSOCIATION WITH THESE LABORATORY TESTS, SMALLER SLABS OR CYLINDRICAL SAMPLES OF DIFFERENT CONCRETE COMPOSITION ARE TO BE INSERTED INTO EXISTING PAVEMENTS, SO THAT THE MODIFICATION WITH TIME OF THE SURFACE ROUGHNESS (SKIDDING RESISTANCE) UNDER VARYING TRAFFIC LOAD CAN BE CONSIDERED. EVALUATION OF THESE TESTS SHOULD LEAD TO A METHOD OF MEASUREMENT WHICH FACILITATES FORECASTING OF THE EFFECT OF THE POLISHING OF AGGREGATES ON THE MODIFICATION WITH TIME OF THE SKIDDING RESISTANCE OF CONCRETE ROADS.