With planning permissions in 2016 up 200% on 2014 levels, building work on farms looks set to increase dramatically. This will drive concrete sales as farmers invest in slatted sheds, dairy parlours and silage pits to modernise their farms through the Targeted Agricultural Modernisation Scheme (TAMS) II. The Department of Agriculture has made a real effort to improve the standard of concrete used in Irish farm construction. In 2015, it released S100, which is the minimum specification the Department uses for concrete used in construction work on agricultural structures. This latest specification introduces some new elements to the concrete specification. These include:
With planning permissions in 2016 up 200% on 2014 levels, building work on farms looks set to increase dramatically. This will drive concrete sales as farmers invest in slatted sheds, dairy parlours and silage pits to modernise their farms through the Targeted Agricultural Modernisation Scheme (TAMS) II.
The Department of Agriculture has made a real effort to improve the standard of concrete used in Irish farm construction. In 2015, it released S100, which is the minimum specification the Department uses for concrete used in construction work on agricultural structures. This latest specification introduces some new elements to the concrete specification. These include:
The extension of the design life of concrete from 20 to 25 years, bringing better value for money.Improved strength made possible by the enhanced specification of concrete with 45N for Mix A and 37N for Mix B.The introduction of cement known as CEM III/A, which may further enhance the durability and strength of concrete as well as reducing its carbon footprint.What is CEM III/A?
The Irish Farmers Journal recently spoke with Andrew McGrane, sustainable business development consultant with Ecocem. McGrane explained that CEM III/A is a blend of two cement types:
One cement type known as Ground Granulated Blastfurnace Slag (GGBS), which is a by-product of the iron- and steel-making industry.The other cement is the traditional Portland cement or CEM I. Cem III/A is made by mixing approximately 50% of GGBS with approximately 50% traditional Portland cement.
“It has enhanced technical and environmental qualities when compared to the commonly used Portland cement type in Ireland known as CEM II/A. When used in concrete, CEM III/A achieves greater durability and higher strength gains than those achieved with CEM II/A,” explained McGrane. He said because of this superior strength and durability, CEM III/A was used in the building of the Paris Metro over 100 years ago.
It was first used in Ireland in the construction of the Cork’s Jack Lynch Tunnel in Cork and since then has been used extensively throughout Ireland.
He said as well as being used in iconic structures such as the Conference Centre Dublin and the Mary McAleese Boyne Valley Bridge, it is widely used in smaller projects including social housing projects, office buildings, farm buildings, wind turbines and precast concrete products such as flood defences, tanks, silage pits and cattle slats.
Extending the life of concrete
McGrane says the usable life of concrete can be extended by making it more durable and this is achieved by using CEM III/A.
“Farms are harsh environments for concrete – with the regular use of heavy machinery the concrete and the exposure to aggressive chemicals such as those found in silage, silage effluent, slurry, and manure,” explained McGrane.
Ali Salih was featured in the Irish Farmers Journal back in 2014 with some results from trials carried out through his PHD. He found that using concrete with the inclusion of GGBS cement had a number of benefits compared with ordinary Portland cement.
The results showed that GGBS has a more chemically resilient mineral composition.
Pictures one and two illustrate how more durable concrete is with CEM III/A in comparison to CEM II/A and are from trials carried out by Salih. The blocks were cured for 28 days and then were immersed in acid and salt solutions. Five 28-day cycles of effluent exposure were repeated over a six-month period.
From the trials, samples incorporating GGBS were found to fare better when exposed to silage effluent. Most were visually unaltered by exposure to effluent, they lost the least amount of mass, and they absorbed less water over time.
Cost benefits
The design life for concrete in the S100 (2015) is a minimum of 25 years. McGrane says by using CEM III/A, that timeline can be extended significantly.
Interestingly, concrete prices can vary from supplier to supplier but no premium is charged for using CEM III/A and the longer lifespan of the concrete can be achieved at no additional cost as CEM III/A is available within the same price bracket as CEM II/A, McGrane claimed.
“As the structures can last longer, the overall cost of the development will be lower over the life of the investment as it will last longer for the same upfront costs,” he added.
The Transport Infrastructure Ireland (TII), formerly the National Roads Authority (NRA), extended the usable life of concrete from 60 years to 120 years by using CEM III/A.
“In this case, the concrete lasts twice a long and as such, time to first repairs and ultimate replacement is pushed out significantly. The result is lower overall cost.”
How to order
There are two concrete mixes described in the S100 (2015) specification and these must be used for building work through the TAMS II. They 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,” he claimed.
For projects undertaken on the farm that do not require readymix concrete supply, CEM III/A can still be used. “CEM III/A is available in hybrid weather resistant 25kg bags from merchants nationwide,” said McGrane.
Environmental contribution
The use of CEM III/A is also beneficial to the environment. “Besides increasing the life of your concrete structure, and reducing the costs over the lifetime of the structure, using CEM III/A can significantly reduce the carbon footprint of concrete used in the farm infrastructure development,” claimed McGrane.
He claims if CEM III/A is used then the carbon footprint of concrete can reduce by approximately 45%, depending on the amount included.
“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 25 tonnes of carbon, the equivalent of offsetting the methane produced by 14 dairy cows over a one-year period,” he explained.
Based on his research, for every six or seven farmers who choose the low-carbon concrete in similar-sized projects, an approximate methane saving larger than an average-sized herd is achieved.
“So in addition to getting stronger and more durable concrete, the farmer can invest in developing the farm infrastructure and achieve a lower environmental footprint for that development while doing so,” McGrane claimed.
The farm environment is very demanding on concrete. Exposure to silage effluent, slurry, cleaning fluids and mechanical abrasion result in significant wear and tear. However, the use of CEM III/A in concrete may offer greater durability and higher resilience to chemicals and sulphates. It may also give a useful life extension beyond the 25 years noted in S100 (2015).Concrete containing CEM III/A is available nationwide through readymix concrete producers and is available through agri-stores and builders’ merchants in hybrid weather-resistant 25kg bags. Read more
Special focus: farm buildings
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