Protecting concrete from chemical attack

Secondary containment systems or bunds can pose serious environmental risks as well as costly maintenance and repairs if not correctly constructed. Choosing the correct protective coating for the bund, one that will be able to withstand the full range of chemicals that are present will help to ensure the long-term durability and integrity of the asset.

Bunds are used to store harsh chemicals and must be correctly designed and lined with a protective coating. This will ensure, in the event of a chemical spill, that the bund wall is protected from corrosion and prevents chemicals from leaking from the bunding area. It will also prevent contamination of the surrounding environment.

According to Bernard Bauer, Technical Manager for Hychem, epoxy coatings such as Hychem’s TL9 are a popular choice for chemical bund protection as they bond well to concrete and can be adapted to meet individual site and containment requirements.

A new and improved formula

Hychem TL9 is designed for use in a wide variety of industries where there is a chance for chemical spillage to occur as well as fluid containment in industries such as mining, power generation, and water treatment.

“Hychem TL9 is ideal for secondary containment systems of a wide range of chemicals, especially strong caustic soda and concentrated sulphuric acid. It is designed for use with concrete structures but is also suited to the protection of steel from corrosive chemicals,” Mr Bauer said.

“TL9 is a flexible, high-impact epoxy coating with excellent resistance to a wide range of chemicals from concentrated sulphuric acid (98 per cent solution) to hydrocarbons, caustic solutions and aqueous salts.

“Recently, we have enhanced the TL9 formula to improve its chemical resistance and overall performance. We have increased its chemical resistance by adding a flake which adds extra protection by making it more difficult for chemicals to migrate through the coating and damage the concrete.

“This makes it particularly effective for bunds and protection against concentrated sulfuric acid.”

Other benefits of TL9 include:

• Highly chemically resistant and specialised novolac coating

• Available as a thixotropic spray formula or can be roller applied

• Film thickness from 150 microns to 3mm possible in one application

• Can be used with Hychem E900, an elastomeric novolac binder that complements the TL9 range, to provide a heavy duty base layer. Proven performer in a range of very harsh acid environments

• 100 per cent success record in bunds

• Long service life and warranty

Understanding a project’s needs

While epoxies are proven to successfully protect bunds, not all epoxies are the same and it is important to carefully examine all design and material criteria to choose the best coating for each project.

“At Hychem we understand that different sites have different requirements, so we offer technical assistance at the design phases right through the lifespan of the product. We work with design teams, consulting engineers, water authorities and project managers to ensure that high standards are applied at every job, in any location.

“Hychem products are also approved by Sydney Water and meet WSAA standards so asset owners can be assured that they are using a product with proven results.”