- Concrete is strong and durable building material engineers have used for centuries when building various types of structures. Civil engineers began using reinforced concrete back in the 1800s and ever since then, the construction industry took advantage of concrete and the benefits it offers.
This is why you would find wastewater tanks and other wastewater management facilities made of concrete! However, steel is now being reinforced into concrete, which is known to affect the material’s durability. If embedded steel corrodes, the concrete ends up cracking and spalling, reducing concrete’s structural integrity while allowing elements to enter the concrete, resulting in deterioration.
Besides that, there are other problems affecting water and wastewater tanks, such as abrasion, freeze-thaw, and even chemical attacks. These may reduce the structure’s service life, which is why it’s important to learn about repairing and protecting waste water structures.
Read on as I talk about the steps and tips to follow to protect concrete tanks in water and wastewater treatment facilities.
1. Diagnose the Problem
Before you perform solutions, it’s important to first know why the concrete material is deteriorating. This will have you address the main cause of the problem to prevent heading into the never-ending cycle of repairs.
You will need to consult experts such as engineers and concrete testers that specialize in concrete evaluation. Your structure will go through field and lab testing to figure out the main cause to recommend long-term solutions.
2. Protect Against Corrosion
If corrosion is the problem, then you can slow it down by using penetrating corrosion inhibitors. This comes in liquid or powder form, decreasing corrosion of reinforced steel.
You can spray this on the surface of concrete, it will then penetrate through hardened concrete down to the rebar. This will form a protective layer around steel Not to worry, as it’s easy to apply without any special equipment required!
3. Protect Against Abrasion, Chemical Attacks, and Freeze-Thaw
Three other common causes of concrete deterioration are abrasion, chemical attacks, and/or freeze-thaw.
- Abrasion damage comes from abrasive effects of debris in contact with concrete, causing it to erode.
- Chemical attacks can come in different forms, such as being exposed to acids or water with low pH levels
- Freeze-thaw cycling may come from the expansion of the material caused by chemical attacks. This causes cracking and/or spalling.
You can protect your tanks by preventing contained water from getting into contact with concrete. This can be done using protective coatings.
4. Moisture Vapor Transmission
This refers to water in gas form trying to exit concrete. With the right temperature and humidity, moisture vapor will be drawn away from concrete and into the atmosphere with evaporation.
If this happens, do not apply an epoxy coating. Instead, wait until late afternoon to evening to apply coating when the sun isn’t out and drawing water vapor out of concrete materials. If the outgassing continues at night, then follow the steps I’ll explain in the section below.
5. Excessive Moisture Content
As mentioned, you should not apply epoxy coating on concrete surfaces with moisture content over 4%. If it is over 4%, the moisture would prevent the epoxy from bonding with a concrete well. You shouldn’t also apply epoxy coating on new concrete until it’s over 28 days old for the concrete to hydrate.
Allow the concrete to dry until it is less than 4%. Take note that this may take some time.
If you have new construction, then you might not be able to wait for 28 days. If so, then apply epoxy-cement mortar, which is a special formula made of cement and water-based epoxy resin. Then, apply an epoxy coating. Doing so will help create a temporary moisture barrier so you can apply epoxy coating successfully, letting it bond with the concrete properly.
Following this method can also fill in bugholes, pores, or honeycombs from the concrete’s surface.
6. Protecting Your Water and Wastewater Tanks
Besides what I mentioned above, here are more helpful tips to help protect your water and wastewater tanks:
- When protecting concrete from potable water tanks, use polymer-modified cementitious coatings. This can bridge cracks and is flexible enough to withstand minimal crack movements from the concrete’s expansion and contraction.
- Protect wastewater tanks with epoxy coating, which has a high degree of chemical resistance. Opt for standard liquid bisphenol A epoxy, along with polyamine hardener.
Wrapping It Up
Hopefully, this article fully informed you about how you can protect your water and wastewater tanks properly. If the concrete on your tanks is faulty and requires repairs, do look into these steps and tips for a long-term solution.
If you have any questions or want to share your insights on concrete water and wastewater tanks, share them in the comments section below. All of your thoughts and knowledge are appreciated.