Traffic noise is the perpetual form of environmental pollution adversely affecting human health in urban environments. This literature review, intended for pavement researchers and professionals, looks at the continuously evolving low-noise asphalt pavement technologies and the techniques which can be used to evaluate them. Test methods for determining the acoustical properties of asphalt pavements are reviewed, in both the laboratory and field environments. The Close-Proximity (CPX) method is the most commonly used field test for pavement acoustics, followed by the Statistical Pass-By (SPB) and On-Board Sound Intensity (OBSI) methods. SPB seems is the most comprehensive methods, while the CPX is more practical. Methods for measuring the acoustical properties in the laboratory include the impedance tube for sound absorption and laboratory pavement noise simulators; with only the larger drum methods being able to produce conditions similar to in-situ. Methods for noise-relevant non-acoustical characteristics like surface texture, porosity and airflow resistivity were also reviewed. Optimizing surface texture at the macro-scale was found to be important in reducing tire/road noise. For pavement types, porous asphalt concrete (PAC) and its variants result in low-noise properties the most reliably, while having some drawbacks in durability and maintenance. Finally, various acoustical performance prediction models were discussed.

In this paper, the combined effect of aging temperatures and cooling medium on the rheological properties of asphalt binder was experimentally investigated and evaluated. Two 70/100 penetration grade binders, which were part of the core materials used by the active RILEM committee CMB-252, were selected for this purpose. The materials were artificially aged to six different conditions, first with the Rolling Thin Film Oven Test (RTFOT) at three different temperatures (123°C, 143°C, and 163°C), and then, with the standard Pressure Aging Vessel (PAV). Next, temperature and frequency sweep (T-f-sweep) tests were performed on the entire set of materials by using the Dynamic Shear Rheometer (DSR) from −30°C to 80°C while low-temperature creep tests were conducted on the long-term aged asphalt binders with the Bending Beam Rheometer (BBR) devices in air and in ethanol, respectively. Then, the 2 Spring 2 Parabolic element 1 Dashpot model (2S2P1D) and Huet model were used to evaluate the rheological properties of asphalt binders based on the DSR and BBR results, respectively. Moreover, two parameters, crossover temperature, T_δ=45°, and the difference in critical temperature, ΔT_c, were used to evaluate the aging properties of the materials. Finally, the relationship between the time domain complex modulus based on DSR and the creep stiffness obtained with the BBR was established to investigate the effect of the cooling medium at low-temperatures. The results indicate that a temperature reduced process may lead to a mitigation of the short-term aging of asphalt binders, while a temperature reduction of only 40°C can result in a consistently milder long-term aging. In the BBR test, higher creep stiffness and smaller m-values can be observed in the air compared to ethanol. Huet and 2S2P1D models show that complex modulus and creep stiffness share the same core parameters only in the case of air. Based on the finding in this research, the temperature reduced mixing process and the use of air for BBR creep tests are recommended.