How 'agri-suitable' is your farm concrete?

The farm environment is very demanding on concrete, with exposure to silage effluent, slurry, cleaning fluids, heavy machinery and mechanical abrasion all taking their toll over time.

To combat this, the Department of Agriculture’s S100 concrete specification – released in 2015 – introduced a cement known as CEM III/A. CEM III/A “significantly enhances” the strength, durability and resilience of concrete, according to Irish cement specialist Ecocem.

CEM III/A is used extensively in building projects such as social housing, office buildings, wind turbines and precast concrete products. However, it is also widely used in agricultural projects such as holding yards, sheds, tanks, silage pits and cattle slats.

CEM III/A is made by mixing a material known as Ground Granulated Blastfurnace Slag (GGBS), which is a byproduct of the iron and steel making industry, with regular Portland cement.

A typical mix comprises 50% of both GGBS and Portland cement. Ecocem manufactures GGBS, which is distributed to concrete producers throughout the country and used to make CEM III/A.

Technical Benefits

CEM III/A enables concrete to achieve greater durability and higher strength gains. The life of concrete can be extended by making it more durable and this can be attained by including CEM III/A in the concrete mix.

In practice, farms are harsh environments for concrete due to the use of heavy machinery and exposure to aggressive chemicals such as those found in silage effluent, slurry, and manure.

The design life for concrete in the S100 (2015) is a minimum of 25 years. However, by using CEM III/A in concrete, that time line can be extended “considerably”, according to Ecocem.

Concrete prices can of course vary from one supplier to another. However, concrete containing CEM III/A has no price premium over regular concrete. This means that the longer lifespan of CEM III/A concrete can be achieved within the same price bracket as CEM II/A based concrete.

As a result, the overall cost of the development can be lower when measured over the usable life of the structure.

Environmental Contribution

Pressure is mounting on all industries to lower their environmental footprint; when it comes to building projects, CEM III/A has an “extremely low” carbon footprint according to Ecocem. CEM III/A can reduce the carbon footprint of concrete by approximately 45%.

For example, a typical farm development comprising approximately 200m³ of CEM III/A concrete for a 25m slurry tank, holding yard, shed and silage pit will save approximately 25t of carbon, Ecocem claims.

This is equivalent to off-setting the methane produced by 14 dairy cows over a 1 year period.

In this manner, farmers produce lower environmental footprints through their investment in infrastructure than previously.

There are two concrete mixes described in the S100 (2015) specification and these should be used for building work through the TAMS II, Ecocem says.

These mixes include:

Mix A – Specification of concrete for silos, silage aprons and silage effluent stores – “45N with CEM III/A”;
Mix B – Specification of concrete for other purposes – “37N with CEM III/A”.

In each case the person ordering the concrete should specify CEM III/A. The new infrastructure can benefit from a significantly longer-lasting concrete if CEM III/A is included.

This is in compliance with the S100 (2015) specification requirements and delivers greater value for money, according to the cement firm.