are collaborating to evaluate the performances of three flexible pavement designs, including two perpetual/long-life (with and without the rich bottom mix (RBM) layer) and one conventional pavement designs. The three flexible pavement designs are being monitored by strain, pressure, temperature and moisture sensors, which are installed in the asphalt, granular and sub-base layers. Two types of ...

The principles underlying current mechanistic–empirical pavement design methods for fully flexible pavements have changed little in the past 30 years. They generally use linear elastic theory to determine the permissible strain at critical locations in the pavement structure to safeguard the road against excessive fatigue and structural deformation. These criteria are calibrated using performan...

The AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) pavement performance models and the associated AASHTOWare® Pavement ME Design software are nationally calibrated using design inputs and distress data largely from the national Long-Term Pavement Performance (LTPP). Further calibration and validation studies are necessary for local highway agencies’ implementation by taking into acc...

in petrochemical industry, the production of polyvinyl chloride (pvc) is accompanied by formation of heavy end wastes which consist of a mixture of di and multichloro compounds as kind of materials which are generated in ethylene dichloride (edc) purifcation. a high quantity of chloro compounds found in the heavy end waste allows it to be polymerized with alkaline polysulfdes to form polysulfde...

The National Airport Pavement Test Facility (NAPTF) was constructed to generate full-scale testing data to investigate the performance of airport pavements subjected to complex gear loading configurations of new generation aircraft. During the first test program, the NAPTF test sections were simultaneously subjected to Boeing 777 trafficking in one lane and Boeing 747 trafficking in another lan...

the available methods for predicting mechanical characteristics of pavement layers are categorized into two general groups, destructive and non-destructive. in destructive method, using coring and pavement subgrade and performing necessary experiments on them, the quantities of layers properties will be identified. in non-destructive method, the attained deflection is measured by applying the l...

Weak bonding between layers of pavement leads to damages on the composite pavement. Bonding plays an important role in the durability and maintenance of composite pavement layers. The present study evaluates the factors effective in bond strength of the interface between concrete and asphalt pavements. The factors considered for this purpose include steel slag percentage in the concrete pavemen...

Dynamic modulus characterizes the viscoelastic behavior of asphalt materials and is the most important input parameter for design and rehabilitation of flexible pavements using Mechanistic–Empirical Pavement Design Guide (MEPDG). Laboratory determination of dynamic modulus is very expensive and time consuming. To overcome this challenge, several predictive models were developed to determine dyn...

Low-temperature cracking is one of the most common road pavement distress types in Poland. While bitumen performance can be evaluated in detail using bending beam rheometer (BBR) or dynamic shear rheometer (DSR) tests, none of the normalized test methods gives a comprehensive representation of low-temperature performance of the asphalt mixtures. This article presents the Bending Beam Creep test...

Since the 1960s, Stone Mastic Asphalt (SMA) pavement surfaces have been used successfully in Germany on heavily trafficked roads. Because of its excellent performance characteristics, road authorities in Germany as well as major European Countries quickly adopted SMA as a standard wearing course. As a consequence of an asphalt study tour in Europe of an American delegation in 1990, SMA test sec...