The renovation of the Jändja fishing grounds on the Pärnu River in Türi, Estonia, was completed in early 2019. The government-funded project helped restore the river ecosystem and adjacent historic buildings. Penetron crystalline materials were applied topically to ensure durability for the concrete structures in constant contact with water.
Located in the center of the Baltic country of Estonia, Türi is a small town of 5,000 inhabitants on the shores of the Pärnu River, one of the longest rivers in Estonia. Thanks to the country’s relatively temperate climate, the Pärnu River is open virtually all year for fishing and boating.
The town’s Jändja fishing grounds were originally enhanced with artificial fly-fishing and spawning areas for zander, pike, perch, or vimba, the region’s most popular game fish. For the Estonian Ministry of the Environment, the US$600,000 renovation project of this section of the Pärnu River would restore a well-known summer destination – frequented by local fishermen and boaters – popular with locals from the town of Türi and tourists from Estonia, Russia, and beyond.
The planning phase of the Jändja project resulted in a long “to do” list: first, the dam and numerous concrete shore and pool elements needed to be repaired and rebuilt. Then, the riverbed and shore areas would be enhanced with the placement of natural stones to create nesting places and whirlpools favored by spawning salmonids and other fish. Finally, the adjacent historical buildings connected to the fishing grounds urgently needed to be renovated; the below-grade basements would demand construction of new concrete structures and repair of previous elements.
“While they often say that ‘fishing provides time to think, and reason not to,’ my team had to think hard about how to complete this job. Because the inclined surfaces of the shore and pool elements were irregular and, in places, needed a very precise layer of topical treatment, much of the concrete construction and repair work was to be done on-site,” explains Andrus Sõna, Director of Penetron Eesti. “It’s toughest to work in the river with continuously running water. We managed to apply the PENETRON crystalline treatment without diverting the water. Hard to imagine – but it worked!”
PENETRON was applied as the waterproofing solution to the concrete structures lining the Pärnu River and to the sections of the dam above the waterline. Once that phase was completed, the water level was temporarily lowered by about 1 meter to expose more of the dam and allow for further PENETRON treatment. Over 1,200 m2 of concrete were treated with PENETRON topical material. The dam and shore elements were completely restored.
The new concrete for the outdoor floor of the historical turbine building was treated with PENETRON ADMIX. The previous metal bridges were replaced, and the areas of deteriorated concrete were repaired and treated with PENETRON to provide a better level of durability, which would also result in fewer maintenance issues.
At first glance, concrete appears indestructible. But the material is essentially a hard, porous and absorbent material that can crack and allow water to easily penetrate through pores, micro-cracks and capillary tracts. In a riverine environment like the Jändja fishing grounds in Türi, this can quickly lead to a wide range of problems that damage the concrete and dramatically affect the durability and lifespan of the structure.
Penetron products are formulated to react with key concrete components to reduce permeability, drying shrinkage and susceptibility to freeze-thaw cycles, as well as provide a permanent self-healing capability. The service life of Penetron-treated concrete can be extended by as much as three times that of conventional concrete.
“The Estonian Ministry of the Environment wanted a long-lasting solution for Jändja that would attract new fish to spawn in Pärnu River,” adds Andrus Sõna. “By the time we finished our work, that’s exactly what we delivered!”