April 5, 2018
Keeping the Nikolayevsky Dry Dock Dry with PENETRON
The historic Nikolayevsky Dry Dock on Russia’s Pacific Coast was relaunched April 2018 after a complete renovation to repair the extensive damage from chloride attack. PENETRON ADMIX was added to all new concrete elements for a permanent and waterproof solution.
Vladivostok, located on the Pacific Ocean in Russia’s “Far East,” is Russia’s largest seaport on the Pacific Ocean and the home base of the Russian Navy’s Pacific Fleet. The Nikolayevsky Dry Dock, over 100-years old, recently underwent a multi-year renovation to repair concrete elements damaged by exposure to seawater (and chloride ions) responsible for corrosion in the dry dock’s concrete elements.
Countering Chloride Attack and Deterioration
Concrete, while an exceptionally hard and strong material, is also comprised of a porous network of microscopic voids that water can enter through. The constant presence of chloride ions from seawater penetrates these pores and is transported to the reinforcing steel, where it initiates the corrosion of the steel – and the corresponding expansion. Ultimately, the concrete can crack and fail, necessitating expensive repair work.
Adding a crystalline admixture (PENETRON ADMIX) to concrete helps significantly reduce permeability of the matrix by permanently sealing microcracks, pores and capillaries. This effectively protects the concrete against water penetration and the effects of deterioration, even under the constant hydrostatic pressure encountered in the dry dock in Vladivostok.
Providing a Durable Concrete Structure
Used for the construction, maintenance, and repair of both commercial and naval ships, the Nikolayevsky Dry Dock was inaugurated in 1891 by Tsar Nikolas. A typical dry dock is essentially a narrow concrete basin with an overflow dam and is open on one end, where it can be closed by gates. The foundation of the basin, the dam and the gate in Vladivostok are made of concrete.
“The Nikolayevsky Dry Dock has gone through numerous expansion, reconstruction and repair efforts over the decades,” explains Igor Chernogolov, President of Penetron Russia. “This time around, we needed a permanent solution that would leave a durable concrete structure in place.”
Resistant to Any Further Chloride Penetration
The most recent renovation project involved all concrete structures of the basin, the overflow dam, and the gates. Work began with the basin; the large granite blocks were dismantled, the underlying structure was cleaned and then filled with new concrete treated with PENETRON ADMIX. The crystalline admixture was also added to all new concrete for the overflow dam and the gates to provide permanent resistance to any further chloride penetration from the seawater.
“The repairs and upgrades for the Nikolayevsky Dry Dock made this a massive project,” adds Mr. Chernogolov. “Fortunately, the local Penetron team in Vladivostok not only provided all the necessary PENETRON crystalline products, but was also able to advise on how to best carry out the repair work on the concrete.”