One of the 12 instrumented sections of the Virginia Smart Road was used to compare measured vertical compressive stress and measured transverse horizontal strain under the hot-mix asphalt (HMA) layer induced by a 25.8 kN (5.8 kip) single tire and a 39.5 kN (8.9 kip) set of dual tires to those calculated using layered linear elastic theory. The pavement section is composed of 38 mm (1.5 in.) HMA wearing surface, 150 mm (6 in.) of HMA base mix, 75 mm (3 in.) of asphalt stabilized open graded drainage layer, 150 mm (6 in.) of cement stabilized aggregate layer, and 175 mm (7 in.) of unbound aggregate base. The subgrade is a fill material composed mainly of rocks. Measured stresses were obtained using pressure cells embedded in the pavement during construction. Horizontal transverse strain was measured using H-type strain gauges that were also embedded during construction. Temperature in the pavement layers was measured using embedded T-type thermocouples. Theoretically calculated stresses and strains were obt...

Asphalt binder ageing alters its chemical and physical properties in a manner to make it brittle and more susceptible to thermal and fatigue cracking. The ageing rate of asphalt binders depends on a combination of different factors related to their chemical composition, environmental conditions and mix design. In order to prevent ageing, anti-ageing additives are used. The selection of the optimal additive should follow an iterative process. The additive choice is made concerning each case studied. Then, the selected modified asphalt binder is short-term aged by RTFOT and long-term aged by PAV and ultraviolet (UV) weathering. Rheology performance parameters are measured by DSR and BBR before and after ageing. Consequently, ageing indices are calculated to evaluate the appropriateness of the additive. The paper discusses several findings on the rheological level accordingly to the literature. Finally, a process is proposed to harmonise the research and the engineering practices in studying anti-ageing additives effects on asphalt binders.

Rehabilitation and repair of flexible pavements produce huge amounts of reclaimed asphalt pavement (RAP) material. Using RAP in the formulation of portland cement concrete (PCC) is a technique that is

The traffic speed deflectometer (TSD) is a device used to evaluate the pavement’s structural condition. Measurements obtained from the TSD are affected by noise, which can make it hard to interpret test results. The main objective of this paper is to develop a denoising methodology to use with TSD measurements and improve pavement structural evaluation. The denoising methodology comprises a computational algorithm to identify significant features in a high-dimensional vector of observations containing white Gaussian noise. The algorithm minimizes the classification error of features in the wavelet transform domain by adaptively selecting the level at which to control the false discovery rate. When tested in a simulation study, the results of the proposed algorithm compared favorably with other state-of-the-art methods. The proposed methodology was then successfully used with TSD measurements to identify possible weak joints in a jointed concrete pavement overlaid with an asphalt layer and to calcu...