Calcium aluminate solutions for pipes
Imerys pipe solutions
What is calcium aluminate binder and how it performs in aggressive environments?
EN 14647 is a European standard that specifies the composition, properties, and conformity criteria for calcium aluminate binder (CAC). Calcium aluminate binder (CAC) is a high-performance, fast-hardening hydraulic binder made from limestone and bauxite. With excellent corrosion, abrasion and sulfate resistance, CAC is widely used in demanding applications – such as wastewater and industrial pipes – where durability, chemical resistance and long-term structural integrity are essential.
Why calcium aluminate is the preferred solution for wastewater and sewer pipe protection?
While conventional Portland cement (calcium silicate cement) is robust enough for potable water applications, pipes for sanitary and wastewater applications require a greater degree of protection to resist the attack of H2S biogenic corrosion.
The development of calcium aluminate binder began around 1850 and was patented by Imerys in 1908. It was developed as an alternative to Portland cement to prevent structural elements from serious sulfate attack.
In wastewater treatment, a common issue is hydrogen sulfide (H2S) corrosion. H2S is a gas that can arise from bacteria in water, and other bacteria above water line oxidize H2S into sulfuric acid, which attacks concrete, mortar and metals.
Calcium aluminate binder unique mineralogy provides specific properties like fast hardening and quick drying, but moreover it provides much improved corrosion resistance – making it the product of choice for wastewater pipes.
Calcium aluminate binder is also known as:
- High alumina cement
- Aluminous cement
- High alumina melted cement
Imerys is your Partner of Choice for CAC pipe solutions
Imerys is a pioneer of calcium aluminate technology, first formulating it over a century ago in 1908. Today, we remain industry experts when it comes to calcium aluminate technology against H2S corrosion. Our Ciment Fondu products have been used in sewers and wastewater facilities since 1930, and we continue to drive innovation in this sector.
Today, we offer a range of calcium aluminate binder technologies. For sewerage assets, our flagship CAC product line is the Sewper® range, which includes:
- SewperCoat®: successfully protecting wastewater assets against corrosion, with more than 30 years of global market presence. SewperCoat® is designed to repair and rehabilitate existing infrastructure.
- Sewper® Liner: an innovation as part of the Sewper® family, SewperLiner® is created for new assets to bond to new concrete, providing long-lasting durability and fewer repairs.
- Sewper® Cast: the definitive solution when very severe H2S corrosion has occurred and the time allowed to repair is very short. By casting a 100% CAC concrete behind formwork, asset owners can restore a very damaged asset in just a few hours and get decades of durability.
For wastewater pipes, Ternal® Calcoat is our best-in-class solution for inner lining in Ductile Iron Pipes, Steel Pipes and Concrete Pipes. Depending on project specifications, Ternal Fondu is another solution in Imerys range.
FAQ
Calcium Aluminate Binder is made from limestone and bauxite, which produce a binder with a unique chemistry and mineralogy. CAC is notably different from conventional Portland cement, providing specific properties like rapid hardening, corrosion resistance, heat resistance and extreme wear resistance.
Imerys manufactures a large range of calcium aluminate binders (CAC), tailored to a wide range of applications like technical mortars, special concrete and refractory products. These include the Imerys Sewper® range for wastewater assets, Imerys Fondag® for waterway infrastructure, and the Imerys Ternal® range which has a variety of applications beyond pipes.
Hydrogen sulfide (H2S) is generated inside wastewater assets when water is deprived of oxygen. H2S is then oxidized by other bacteria into sulfuric acid that attacks building materials including metal and concrete. Because this type of acid attack arises from bacterial activity, it is referred to as Biogenic H2S Corrosion or Microbiologically Induced Corrosion (MIC).
A lot of academic research has examined how CAC protects wastewater assets against H2S corrosion. Various mechanisms contribute to outstanding durability of CAC observed in the field. Key among these are the very good chemical stability of alumina gel (AH3) and the inhibition of bacteria growth when aluminium ions are released into the bacteria biofilm.
Applying polymer resin, such as epoxy, is a common choice for protecting wastewater infrastructure from corrosion. However, the rate of premature failure suggests that this is a less reliable solution than CAC. Protecting wastewater assets with a layer of calcium aluminate mortar is a significantly more durable and reliable solution. This protection can be applied during construction of the asset, or during later rehabilitation when an asset has already been subject to H2S corrosion. Imerys product ranges such as SewperCoat®, Sewper® Liner and Sewper® Cast have all been specifically developed with this targeted application in mind.
Yes, SewperCoat®, Sewper® Liner and Sewper® Cast bear the CE marking relevant to their specific category of application, either EN 1504-2 or 1504-4.
