Abstract: Plastic concrete could well adapt to foundation settlement due to its low elastic modulus and large deformation. As a result, it is widely used in the construction of cutoff wall in hydropower projects. As to the anti-seepage project of cofferdam in Lufeng nuclear power plant, in order to make full use of resources on site and reduce the cost of project, we adopted stone ballast to take the place of pebble and sand for mix proportion design of plastic concrete. Then we determined the technical indexes of plastic concrete by performance test, and detected the anti-seepage effect of the mix proportions through water injection test and hole imagery. Results show that when the sand ratio remains unchanged, the impermeability improves greatly with bentonite content increases, while the strength decreases little, which meets the requirements for performance index. The cutoff wall is also in good condition. The mix proportion with stone ballast replacing pebble and sand is verified to be feasible.

Key words: plastic concrete, stone ballast, mix proportion, water injection test, hole imagery