EFFECT OF ADMIXTURES OF RUBBER TO GUSSASPHALT SURFACINGS

EINFLUSS VON KAUTSCHUKZUSAETZEN BEI GUSSASPHALTDECKEN

QUASI STATIC COMPRESSION TESTS ON RUBBER-MODIFIED BITUMEN AND GUSSASPHALTS HAVE SHOWN THAT THE ADMIXTURE OF SYNTHETIC RUBBER CHANGES THE THERMOVISCOELASTIC PROPERTIES OF ROAD MATERIALS. TO OBTAIN DATA ON THE BEHAVIOUR OF A MODIFIED SURFACING UNDER FATIGUE OR ALTERNATING LOAD, AND ON ITS LIFE, STUDIES ARE TO BE UNDERTAKEN IN WHICH SAMPLE CUBES ARE SUBJECTED TO A LOW-FREQUENCY COMPRESSION LOAD WHICH IS DISTINGUISHED FROM THE HIGH-FREQUENCY LOADING OF MOVING TRAFFIC ON AN OPEN ROAD IN THAT IT OFFERS THE POSSIBILITY OF REGENERATION. ON A 2 KN TEST MACHINE WITH A TEMPERATURE CHAMBER 7 CM CUBES ARE TO BE EXPOSED TO ALTERNATING AND INCREASING LOADING WITH FREQUENCIES UP TO 0.1 HZ OVER A LONG PERIOD. IT IS ANTICIPATED THAT FREQUENCY AND LOADING AMPLITUDE WILL BE VARIED IN THREE STAGES. SLIDING LAYERS BETWEEN SAMPLES AND COMPRESSION PLATES SHOULD ENSURE LATERAL SLIPPING OUT OF THE SAMPLES AND A UNIFORM STATE OF DEFORMATION. PARALLEL TO THE LABORATORY STUDIES MEASUREMENTS OF LAYER THICKNESSES AND OBSERVATIONS OF ROAD CONDITIONS ARE TO BE CARRIED OUT ON EXPERIMENTAL ROADS.