The Long Term Pavement Performance (LTPP) program is a 20-year study of inservice pavements across North America. Its goal is to extend the life of highway pavements through various designs of new and rehabilitated pavement structures, using different materials and under different loads, environments, subgrade soil, and maintenance practices. LTPP was established under the Strategic Highway Res...

PROBLEM STATEMENT When designing and evaluating asphalt pavements, engineers must have an understanding of how the pavement materials will react to the stresses and strains of vehicle loads at varying temperatures. When a load is applied to asphalt concrete at a certain temperature, to what degree will the pavement "bounce back" to its original height? Pavement designers predict this spring-lik...

Pavement surface deflection of a highway is a primary factor for evaluating the pavement strength of a flexible pavement. Benkelman Beam Deflection (BBD) technique is widely used in the country for evaluating the structural capacity of an existing flexible pavement as also for estimation and design of overlays for strengthening of a weak pavement. The field test for measuring the surface deflec...

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 ...

Pavement condition assessment is essential when developing road network maintenance programs. In practice, the data collection process is to a large extent automated. However, pavement distress detection (cracks, potholes, etc.) is mostly performed manually, which is labor-intensive and time-consuming. Existing methods either rely on complete 3D surface reconstruction, which comes along with hi...

Recently developed Mechanistic-Empirical Pavement Design Guide (MEPDG) determines the probable total rutting by summing up the deformations of all layers of the trial pavement. If all distresses outcomes including rutting are within the specification the trial section is designed for construction. Therefore, vertical deformation (or strain) needs to be measured to validate the MEPDG for local c...

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 focus of the current project funded by MIOH-UTC for the period 9/1/2010-8/31/2011 is to enhance our earlier effort in providing a more robust image processing based pavement distress detection and classification system. During the last few decades, many efforts have been made to produce automatic inspection systems to meet the specific requirements in assessing distress on the road surfaces...

Heavy Weight Deflectometer (HWD) tests were routinely conducted on three Portland Cement Concrete (PCC) test items in the Federal Aviation Administration’s (FAA's) National Airport Pavement Test Facility (NAPTF) to verify the uniformity of the test pavement structures and to measure pavement responses during full-scale traffic testing. A six-wheel aircraft landing gear with dual-tridem configur...

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...