Abstract: In middle route and first stage of South-to-North water diversion project, several high fill sections of main channel were not implemented reinforcing measures such as anti-seepage wall and geomembrane thickening. For the purpose of strengthening waterproof function of these segments, a new polyurea material was used on the structural joint surface of canal slope and bottom. The polyurea material should have good adaptability of temperature deformation for structural joint and good bonding properties for concrete, so the crack repair material system CW680 of novel slow reacting polyurea developed by Changjiang River Engineering Technology Company was applied to repair structural joint of the sixth segment of the canal at Xichuan county in Henan province. Through experiment for 3 months, the waterproof ability of the novel material is testified to be good, and safety operation of the canal can be guaranteed by using the repair material.

Key words: South-to-North water diversion project, high fill canal, structural joint, polyurea, rapair material slow reaction