In summing up currently home and abroad study result on bridge evaluation and combining the characteristics of the old reinforced concrete bridges on country highway, in this article it carried on a further research to evaluation methods of damage state of the old reinforced concrete bridges on country highway.

The techniques in the paper may contribute referential inspection and test items,contents and means to the evaluation of durability of the concrete used for bridges in China,and also reference to the design of the durability of concrete bridges.

The coastal reinforced or prestressed concrete bridges are always liable to chloride corrosion permeating on the reinforcement therein and durability of the structures is thus degraded.

When the section of the concrete bridge is enlarged,the additional stressed effects of the interface of the new and old concrete will be larger for its different ages,so the paper according to the analysis of some project,illustrates the distributing features for the additional stress and suggests to adopt respective measures in order to have a better combination of the new and old concrete.

Resource study status of old building demolition waste was summarized,resource methods for waste wood,waste concrete,waste tiles,waste roofing material and demolition waste powder were introduced,application of the old building demolition waste as pile filler to mollisol foundation strengthening was also generalized.

Ultrasonic experimental research on bond quality of new-to-old concrete interface with different roughness;

About the interface nature research of the new and old concrete;