The first step: a large number of preliminary investigations. Including surveys of historical data, damaged pavement condition, road structural strength, material properties such as the old pavement. Historical data include viewing the same route survey design, construction, completion, maintenance and repair, and traffic information.
With the large number of highway construction. Semi-rigid material with its excellent engineering class performance and significant economic benefits have been widely used in the construction of highway and road construction increasingly occupies a special importance.