Efeito da densidade máxima teórica na dosagem e no comportamento mecânico de mistura asfáltica tipo CBUQ

Abstract

Based on the bulk specific gravities of the aggregates and the compacted mixture and the theorical maximum specific gravity (Gmm), one can determine the volumetric characteristics and the bitumen content of an asphalt mixture. Different procedures to determine the Gmm can lead to different values, also affecting the volumetric parameters. In Brazil, Gmm is determined indirectly from the mixture composition and the relative densities of its constituents. Besides the calculating Gmm from the densities of the constituentsm, the present study investigates the laboratory procedures: (i) ASTM D 2041, which uses a vacuum pump (Rice method) and (ii) method using kerosene. Thwe differences in the Gmm values obtained by the investigated procedures are discussed, evaluating the influence of these differences in the volumetic parameters and, consequently, in the choice of the optimum asphalt content. Finally, the mechanical behavior of the resultant mixtures is evaluated by the indirect tensile strenght, reilient modulus and fatigue life.