Concrete is the fundamental element for most agricultural structures on Irish farms today. The quality of concrete has improved significantly since it was first used on Irish farms – it has become much stronger and harder wearing. Improved concrete specifications have aided these improvements. Farmers planning on carrying out work involving concrete should make themselves aware of the specifications required, especially when building with Department grant aid. The specifications for items and building materials are listed on the Department’s website under the farm building and structures specifications section.
Concrete is the fundamental element for most agricultural structures on Irish farms today. The quality of concrete has improved significantly since it was first used on Irish farms – it has become much stronger and harder wearing.
Improved concrete specifications have aided these improvements. Farmers planning on carrying out work involving concrete should make themselves aware of the specifications required, especially when building with Department grant aid. The specifications for items and building materials are listed on the Department’s website under the farm building and structures specifications section.
The minimum specifications for concrete are set out on the Department’s website under S100. These minimum specifications will be of interest to every farmer who plans on undertaking building work as part of the Targeted Agricultural Modernisation Scheme (TAMS) II.
There are two strength classes of concrete given in this specification:
Concrete for silos, silage aprons and silage effluent store.Concrete for all other purposes. The Department says that those two grades will be the only ones permitted to be used in agricultural buildings.
Concrete for silos, silage aprons and effluent store
Because of the corrosive nature of silage effluent, this is the strongest specification. The Department specifies that if you are ordering concrete for walled silos, silage aprons, silo channels and purpose-built silage effluent tanks from a producer, it should have a 28-day cube crushing strength of 45N/mm².
When ordering, use the “S.100 Mix A” form or request 45N concrete with 360kg/m3 cement minimum, 0.5 water cement ratio maximum and slump (workability of fresh concrete) class S2 or S3. The concrete has to be certified to IS EN 206 standard.
Concrete for all other purposes
For all other purposes including slurry tanks where silage effluent might be directed, concrete should be purchased with a 28-day cube crushing strength of 37N/mm².
When ordering this mix from a producer, a “S.100 Mix B” form should be used or request 37N concrete with 310kg/m3 cement minimum, 0.55 water cement ratio maximum, and slump class S2 or S3, certified to IS EN 206, for use to specification S.100.
There have been 25,520 applications to TAMS II since it was launched, with almost €186m paid out to farmers
Curing
Curing is an important part of ensuring the concrete supplied is fit for purpose. Curing involves protecting the surface of the newly poured concrete from premature drying out. If it dries out too fast, the surface layer will not achieve its potential hardness. It takes 35N concrete at least 28 days to reach its full design strength. Different severe weather events have potential negative effects on freshly laid concrete and should be protected against:
Cold weather: frost damage to concrete.Hot weather: potential loss in strength and durability due to accelerated setting time.Heavy rain: surface damage and reduced strength.Strong wind: rapid drying. Some farmers/contractors ask the concrete lorry driver to add water to the mixture to help increase the workability of the concrete. However, adding water severely reduces the potential strength of the concrete.
If a contractor or work team wants workable concrete, this can and should be ordered and made accordingly in the batching plant by adjusting aggregate size or adding plasticiser.
CEM III/A
Farmers who want to increase the longevity of their concrete even further might consider using Cem III/A. It is a blend of two cement types:
One cement type known as ground granulated blastfurnace slag (GGBS), which is a byproduct of the iron and steel-making industry.The other cement is the traditional Portland cement or CEM II/A. It is made by mixing approximately 50% of GGBS with approximately 50% traditional Portland cement. It has enhanced technical and environmental qualities when compared with 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. There are no cost differences in using CEM III/A compared to ordinary Portland cement.
Top tips
Plan every job before calling in a lorry load of concrete.Vibrate concrete to remove entrapped air.Allow the concrete time to gain sufficient strength before applying weight. Properly placed, vibrated and cured concrete will achieve 50% of its design strength in three days, 75% in seven days and 100% in 28 days.Don’t place concrete in extremes of weather.TAMS tranche deadline approaches
The 16th tranche of TAMS II is set to close for applications on 10 January 2020. The 17th tranche will open immediately after this current tranche closes and will remain open for applications until 24 April 2020.
There have been 25,520 applications to the scheme since it was launched, with almost €186m paid out to farmers.
The overall closing date for TAMS II is 31 December 2020 unless it is extended in the meantime. Farmers planning on carrying out work this year or next with the aid of TAMS II grant aid should really be making arrangements as soon as possible to get their online applications in on time. Grant rates vary from 60% to 40% depending on eligibility, with qualifying young trained farmers eligible for the higher rate of aid for certain investments.
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