PURPOSE: To enhance durability by constructing a base which is a mixture of crushed stones, natural earth and a soil stabilization agent between a subgrade and a concrete-made surface layer and fixing the strength of base materials so as to become highen than a certain level.

CONSTITUTION: Crushed stoner and earth are mixed at their volumetric ratio of 30:70 to 50:50. Iron oxide particles of 1/1000mm and below, quick lime, calcium hydroxide and lime stone fine particles are mixed at their weight ratio so as to prepare a soil stabilization agent. A base which comprises a mixture of crushed stones and earth added with the soil stabilization agent is laid between ballast and cement concrete or roller compacted cement, which is used as a surface layer. The strength of the base material is specified to exceed 4 day submergence CBR 150% and 28 day submergence CBR 260%. What is more, the thickness of the base is designed so that the maximum strain of a paved surface may not exceed 0.3mm.