The importance of considering the aggressiveness of the water when choosing the most suitable coating for concrete tanks
Concrete is a material widely used in the construction of water reservoirs. However, when the water has aggressive chemical characteristics, such as a low pH and low mineralization, negative effects can occur due to direct contact with the stored water.
Concrete is used to encase reinforcing steel, which, thanks to its high pH, protects and passivates the steel, thus preventing oxidation. However, corrosion of the reinforcement can occur if oxygen reaches the steel, particularly due to carbonation, linked to the dissolution of the concrete, a phenomenon generally associated with aggressive waters.
RYZNAR AND LANGELIER INDICES
When choosing the appropriate waterproofing mortar to protect reinforced concrete structures intended for water storage, it is essential to take into account the aggressiveness of the water in question.
Several tools can be used to assess this aggressiveness, notably the Ryznar index and the Langelier saturation index. These calculations are fundamental for determining the type of waterproofing mortar to use.
The Ryznar index measures the aggressiveness of water in relation to the formation of limescale deposits. The higher the index, the less prone the water is to forming scale. Conversely, the Langelier saturation index measures the water's tendency to dissolve minerals, particularly calcium carbonate.
To perform these calculations, it is possible to use online tools such as those offered by Lenntech.
Ryznar's index can be calculated using the tool available at:
https://www.lenntech.com/calculators/ryznar/index/ryznar.htm
The Langelier saturation index can be calculated via:
https://www.lenntech.com/calculators/langelier/index/langelier.htm
As mentioned in the article
«Aggressiveness and corrosivity of water in crystalline terrains of Northern Portugal – The need to use waterproofing coatings», written by Carlos Pinto,
In order to avoid structural degradation processes resulting from contact with aggressive waters, it is recommended to use suitable waterproofing coatings to extend the life of structures and prevent problems such as cracking, concrete degradation and reinforcement corrosion.
ECOFIRMA is a company specializing in the repair, rehabilitation and waterproofing of structures under construction, using waterproofing products based on chemical compounds with properties which, in association with selected cements and aggregates, allow the pores of the concrete to be sealed and prevent the aggressive action of certain waters.
Waterproofing has become an essential component of any construction project today. Surfaces exposed to water, such as tanks, must be adequately protected to ensure the structure's durability.
ECOFIRMA has the technical capacity to offer solutions ensuring greater durability than traditionally achieved for this type of structure.
When choosing the appropriate waterproofing mortar to protect reinforced concrete structures intended for water storage, it is essential to take into account the aggressiveness of the water in question.
Several tools can be used to assess this aggressiveness, such as the Ryznar index and the Langelier saturation index. These calculations are essential for determining the type of waterproofing mortar to use.
The Ryznar index measures the aggressiveness of water towards scale formation. The higher the index, the lower the water's tendency to form deposits. Conversely, the Langelier saturation index measures the water's tendency to dissolve minerals, particularly calcium carbonate.
WATER CHARACTERIZATION
To apply the Ryznar and Langelier indices, it is necessary to carry out analyses of the water that will be used in the reservoir.
These analyses include measuring pH, alkalinity, hardness, chlorides, sulfates, among other parameters that can influence the aggressiveness of water towards concrete.
Based on these results, it is possible to select the most suitable waterproofing mortar for each situation, thus guaranteeing the protection of the structure against the corrosive action of water and increasing its durability.
APPROPRIATE CHOICE OF WATERPROOFING SYSTEM
ECOFIRMA is a company that takes into account the specific characteristics of water in each site where it operates.
It is important to emphasize that water can vary in its composition and properties depending on geography, local geology and its use.
For example, water in a coastal region may have a higher concentration of chlorides due to marine influence, while water in an industrial area may contain high levels of heavy metals.
Based on these elements, ECOFIRMA adopts a personalized approach for each project, carrying out detailed water analyses and selecting the most suitable waterproofing solutions to protect the structure against the effects of the water in question.
Thus, it is possible to guarantee the durability of the structure and prevent potential future problems.