Abstract: Erosion damage to concrete structures is often observed in various flow channels, and usually using existing repair materials cannot insure a good durability of the repaired structure. To achieve better repair effect, we develop new composite materials and conduct laboratory tests on their abrasion resistant properties, thermal compatibility, and mechanical properties under hydraulic environment. Mechanical analysis of the repaired structures and field repair tests of a diversion channel and an overflow surface have been carried out. The results show that our new composite materials achieve better performances than the other similar materials in China – wet adhesive strength of up to 3.95 MPa between epoxy interface agent and original concrete, compressive strength of underwater abrasion resistant mortar of up to 85.99 MPa, and abrasion resistant strength of up to 2545.2 h/(kg/m2) when protected with a flexible nano-ceramic coating. And they have good compatibility with concrete and can adapt to the deformation of concrete both in high and low temperature environments; in the range of -20℃~40℃, the structures repaired using them will not crack or be corroded, keeping structural integrity. The site repair effect is considerably fine, and no obvious damage to the surface has been observed after sufficient times of flood discharge. Thus, we suggest that these new composite materials be widely applied to similar projects to achieve a good durability and better effect of concrete structure repair.

Key words: hydraulic material, composite repair material, abrasion resistant mortar, applicability, grinding and cavitation erosion