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...

Each year, more than 25 percent of highway fatalities in the United States occur at or near horizontal curves, according to the Federal Highway Administration (FHWA). In an attempt to save lives and prevent injuries, some 30 states across the U.S. are applying high friction surfaces (HFS) to improve skid resistance at locations with a high incident of vehicle crashes such as severe horizontal c...

1. A strain of pure epithelial cells was obtained from the part of the iris which adheres to the extirpated lens. 2. The optimum condition under which epithelial cells grow in vitro is on the free surface of the plasma clot under a film of embryonic tissue juice. 3. The epithelial cells did not dedifferentiate. Although the strain is 3 months old, they grow as a pavement membrane and have kept ...

In this study, an artificial neural network was developed in order to analyze flexible pavement structure and determine its critical responses under the influence of standard axle loading. In doing so, more than 10000 four-layered flexible pavement sections composed of asphalt concrete layer, base layer, subbase layer, and subgrade soil were analyzed under the impact of standard axle loading. P...

The structural features of the chloride-secreting opercular epithelium of Seawateradapted killifish (Fundulus heteroclitus) were examined by thin-section and freeze-fracture electron microscopy, with particular emphasis on the morphological appearance of occluding junctions. This epithelium is a flat sheet consisting predominantly of groups of mitochondriarich chloride cells with their apices a...

1 Climate change has the potential to impact long-term road pavement performance. Consequently, to 2 maintain pavements within the same ranges of serviceability as before, current pavement maintenance 3 strategies need to be re-assessed and, if necessary, changed. Changes in maintenance may lead to 4 different agency costs and user costs as a consequence. This paper commences by defining an 5 a...

In pavement management, prioritized resource allocation is imperative given the fact that there is rarely enough funding with highway agencies to address all the pavement sections. In view of the complexity involved in the decision making process, subjective evaluation based on expert’s judgments is unavoidable. Analytic Hierarchy process (AHP) has been applied by researchers to solve pavement ...

Longitudinally tined (LT) concrete pavement surfaces were shown to produce less noise than transversely tined (TT) ones, making them more desirable where traffic noise may be an issue, if the two textures are shown to have equivalent safety performance. The present effort focused on rural freeway crashes between 1991 and 1998. This guaranteed the presence of high speeds and absence of various f...

Highway pavement are deteriorating fast due to lack of timely maintenance, leading to higher vehicle operating costs, increasing number of accidents etc. Thus, timely maintenance of the highway pavement is essential. Because, once pavements start to deteriorate; they deteriorate rapidly beyond the point where maintenance is effective. Thus, there is an urgent need to develop a strategy for main...

The bearing capacity and service life of a pavement are adversely affected by the presence of undrained water in the pavement layers. In cold winter climates, such as in Iowa, this problem is magnified further by the risk of frost damage when water is present. Therefore, wellperforming subsurface drainage systems form an important aspect of pavement design by the Iowa Department of Transportati...