一、总的情况早在上世纪下半叶,西欧及美国个别大城市,如伦敦、巴黎、纽约等,即开始修筑水泥混凝土路面,到1919年,美国拥有混凝土路面的公路达5,000～6,000公里。到本世纪二十和三十年代,混凝土路面有了较快的发展。美国在1924年拥有混凝土路面的公路 First, the general situation As early as the second half of the last century, Western Europe and the United States in major cities such as London, Paris, New York, that is, began to build cement concrete pavement, by 1919, the United States has a concrete pavement of 5,000 to 6,000 km of highways . Twentieth and the thirties of this century, the rapid development of concrete pavement. The United States owned a concrete road in 1924