Managing Concrete Cooling Tower Basin Leaks

 

Cooling towers function by utilizing coolant fluids which must be retained and recycled through the system. This is true for both mechanical and natural draft cooling tower technologies. A lot of people think of concrete as the superman of building materials which is just impervious, which is not true.  Concrete is chemically more similar to ceramic materials in terms of chemistry.  Ceramic products such as fired pottery or dishware are considered “vitreous” materials. Whereas concrete is a sub-vitreous construction material which is more porous which allows a degree of water permeability. Being a bit like a hard sponge the dried capillaries of concrete contribute to concrete’s permeability. Concrete cooling tower basin repair extends the life of the cooling tower and keeps operating costs more affordable.

Water Retention in Reinforced Concrete

When concrete elements are initially installed the design and concrete consistency play a major role in the long term durability of your concrete cooling tower water basin. When leaks are found or concrete is experiencing degradation concrete epoxy coatings can be applied to cooling tower water basins to help protect the concrete and extend the life of the cooling tower.

• The concrete basins in cooling towers should include the following details which will help manage issues with water retention and durability.
• Cement should be ordered with low water-to-cement ratios. This means that as the concrete dries there will be less shrinkage due to water evaporation.
• Conform to ACI-350 standards for embedded reinforced steel which will help restrain cracking from material volume shrinkage.
• Utilize formwork systems which do not include full wall section thicknesses.
• Minimize the quantity of construction joints or proposed joins involved in the formed edges of the basin.
• Institute a quality assurance and quality control phase in your concrete construction project.

Concrete Cooling Tower Water Basin Defects

Significant factors that lead leaks in concrete water basins in cooling towers are:

• Misplaced steel bars inside the concrete mass which fail to control volume shrinkage.
• Unconsolidated concrete which was not poured right and provides a direct conduit through the concrete.
• Inadequately sealed concrete which leads to the corrosion or the embedded steel.
• Absences or misplacement of water stop glands which prevent water from passing through expansion joints.

Leak Mitigation in Cooling Tower Basins

A lot of times cooling tower owners think that waterproofing is a one and done deal when the cooling tower is first constructed. There are both positive and negative side waterproofing measures which help prevent leaks and protect concrete. Positive side generally includes the waterproofing measures which are done before the cooling tower has been placed in service. Negative side waterproofing usually refers to coatings and repairs which are done after the cooling tower is in use or even when it is on-line.

Concrete Cooling Tower Basin Repair

There are different approaches for the repair of concrete cooling tower water basins. The appropriate repair will depend on the size of the leak and the amount of water leaking from your cooling tower. These repair approaches include:

• Coatings
• Grouting
• Flow rerouting
• Surface & Joint Seals
• Membranes

Coatings

Epoxy coatings are a common and effective method for repairing concrete in cooling towers. The application involves the epoxy coating being bonded to the concrete surfaces of the cooling tower after proper cleaning and preparation. Specially designed epoxy coatings are used for these environment which are designed to cope with the constant presence of the chemicals used in cooling tower water programs.

Grouting

Grouting, much like we imagine in tile installation, involves injecting water-stopping materials around or behind structures which forms a barrier for process fluids and water. Generally these materials solidify to be anywhere from completely rigid to semi-gelatinous. This means that depending on the size of the gap or crack grouting can be flexible to follow expansion or rock solid to provide added structural rigidity.

Flow Rerouting

In emergency situations when there is heavy flow using re-circulating pumps or sand-bags.  This is due during monsoon conditions or when process fluid surges crest. In a lot of cases the leakage cannot be stopped until the pressures are lowered after bypass piping is installed into the joints or cracks in concrete members.

Surface & Joint Seals

Surfaces that experience cracking or joints that aren’t holding water can be repaired by installing materials over or in these areas. The materials used are highly specific to this application and must abe able to transmit and absorb loads and energy. This includes any flow or movement during the operation of the cooling tower.

Membranes

Membranes are typically part of positive side concrete cooling tower basin waterproofing as they require a very high level of quality assurance. These systems can be both unbounded and bonded sheet systems that feature welded seams designed to contain the process water.

Concrete Cooling Tower Basin Repair

All Kote Lining Inc. offers service valleywide in Phoenix, AZ. We specialize in the evaluation of cooling tower maintenance including the repair of concrete cooling tower basins. From the nozzles, through the system, and back to the basin we can maintain, repair, and replace any element on your cooling tower to refurbish your cooling tower and extend its working lifespan.  Properly servicing and repairing your cooling tower will save companies from inflated operating costs from having to prematurely replace cooling tower systems.

For more information about how we can help repair and extend the life of your cooling towers:
Call All Kote Lining, Inc at 480-966-4446.