Pavement Analysis and Design Second Edition
plays an important role even up to the present day. Prior to the early 1920s, the thick -
ness of pavement was based purely on experience. The same thickness was used for a
section of highway even though widely different soils were encountered . As experience
was gained throughout the years, various methods were developed by different agencie s
for determining the thickness of pavement required . It is neither feasible nor desirable t o
document all the methods that have been used so far . Only a few typical methods will
be cited to indicate the trend.
Flexible pavements are constructed of bituminous and granular materials . The firs t
asphalt roadway in the United States was constructed in 1870 at Newark, New Jersey .
The first sheet-asphalt pavement, which is a hot mixture of asphalt cement with clean ,
angular, graded sand and mineral filler, was laid in 1876 on Pennsylvania Avenue i n
Washington, D.C., with imported asphalt from Trinidad Lake. As of 2001 (FHWA,
2001), there are about 2 .5 million miles of paved roads in the United States, of whic h
94% are asphalt surfaced .
asphalt roadway in the United States was constructed in 1870 at Newark, New Jersey .
The first sheet-asphalt pavement, which is a hot mixture of asphalt cement with clean ,
angular, graded sand and mineral filler, was laid in 1876 on Pennsylvania Avenue i n
Washington, D.C., with imported asphalt from Trinidad Lake. As of 2001 (FHWA,
2001), there are about 2 .5 million miles of paved roads in the United States, of whic h
94% are asphalt surfaced .
EmoticonEmoticon