To deal with the problem there was no strict evaluation method and standard, an experiment was designed to evaluate the segregation degree of road concrete. Furthermore, the status and index of segregation was determined too. The testing analyzed the distribute character of coarse aggregate in road concrete. Based on the method of digital image processing and the assumption that particles in fresh concrete conform to uniform distribution, a model that size of coarse aggregate against vertical section (the direction against vertical section of specimen) in concrete conforms to continuous distribution was established. Segregation degree—a parameter to characterize the degree of segregation of particles in concrete was proposed. Meanwhile，a reference standard to evaluation segregation degree was given.

Subgrade compactness is the assurance of road strength and stability requirements, is an important indicator of the quality control of road works. Summarize the subgrade compaction detection methods. Expound the inspection and assessment of the compactness methods and precautions combined with the new specification can provide technical reference.