Graving Dock Service Life Extension

The owners of a facility which builds and repairs nuclear submarines for the U.S. Navy wished to rebuild the walls of three of its graving docks. For each graving dock, the walls were approximately 50 ft. high, an average of 12 ft. thick, and over 2,000 ft. long. During service conditions, the walls were to be subjected to periodic wetting and drying, freezing and thawing and seawater exposure. The owners desired wished to achieve a long service life, so high performance concrete was specified, and the walls were designated to be mass concrete.

For one of the graving docks, CTLGroup worked with the general contractor and the concrete supplier to develop unique low heat of hydration high-performance concrete mix designs to meet the requirements of the project specifications. CTLGroup also performed thermal modeling of the mass concrete and developed thermal control plans so that the contractor could construct and control temperatures within mass concrete walls in a cost-effective manner with minimal impacts on the schedule. As part of this, CTLGroup recommended specification changes for the mass concrete.

For the other graving docks, CTLGroup personnel participated in the contractor's bid and qualification presentation to the owner. After the contractor was awarded the contract, CTLGroup optimized the concretes to reduce costs and maintain durability, and provided on-call engineering assistance and testing services to the contractor for construction-related issues.