Completed in July 2017, the newly renovated Admiralty Shipyards in St. Petersburg, Russia, employed PENETRON crystalline technology to counteract decades of corrosion and concrete decay from constant chloride penetration. The (now) waterproof and durable shipyards have already regained full functionality again.
Originally founded in 1704 by Peter the Great, the historic Admiralty Shipyards in St. Petersburg is one of the largest marine facilities in the country. Each shipyard is double the length of a football field at 12 m (39 feet) wide; about 50 m (165 feet) of the shipyard structures are submerged completely under water.
“This was a monumental construction and repair project that took years to complete,” explains Yevgeniya Kuzminova, Director of PENETRON St. Petersburg. “All the new and repaired concrete exposed to the level of chloride penetration encountered in the shipyard required a permanent and durable solution.”
For any concrete structure exposed to such an aggressive marine environment, the main challenges to achieving a durable concrete matrix are attacks by aggressive chemicals such as chlorides, sulfates and acids, and corrosion of the reinforcement steel due to seawater penetration.
The active ingredients in PENETRON products react with concrete minerals to form insoluble crystals, which fill in cracks, pores and voids in concrete. The resulting crystalline network keeps seawater from penetrating into the concrete, even under high hydrostatic pressure, making the matrix impermeable to any chloride penetration. PENETRON-treated concrete reveals vastly improved chloride diffusion and sulfate resistance, as well as self-healing capabilities. In-situ testing has shown the service life of crystalline-enhanced concrete to be about three times that of conventional concrete.
PENETRON crystalline material was topically applied on all renovated concrete surfaces at the shipyard. Earlier this year, during the winter months, PENETRON ADMIX was added to the concrete during batching because it was the only solution that could be applied in such cold temperatures. The treated concrete was used for construction of the battery charging substation located just 10 m (33 feet) from water. The PENETRON St. Petersburg team took the concrete samples during batching time to guarantee the performance of the concrete mix.
“We used a full range of PENETRON topical and admixture products to protect the new and renovated concrete structures during the renovation of the shipyard structures, including the concrete wharves, dry docks and other concrete elements,” adds Yevgeniya Kuzminova. “A further benefit is that future maintenance costs of the concrete can also be significantly reduced.”
One of the oldest and largest shipyards in Russia, the Admiralty Shipyard accommodates ships up to 250 m (820 feet) in length and 35 m (115 feet) in breadth. The facility is also a major shipbuilder; for example, about 15% of all submarines in the world (by tonnage) were manufactured at the Admiralty Shipyards. The facility has produced hundreds of battleships and cruisers, as well as large merchant ships, icebreakers, rescue and salvage ships, etc., and even the roof of St. Isaac's Cathedral in St. Petersburg.