Key Features of Sulphate Resistant Concrete

Lots of concrete construction projects are built underground or underwater, which presents its own challenges. Not only is there the issue of access, but sometimes conventional waterproof concrete will not provide enough protection from the elements.

Here Madmix, who supply sulphate resistant concrete to homes and business in Newmarket, Cambridge and the surrounding area, look at how this type of concrete admixture is the solution.

The Chemical Problem

Sulphates are usually the result of industrial waste finding its way into local streams, groundwater and other water sources. Mills and mines have been reported to be among the worst offenders.

Soil also contains natural sulphates, which are not harmful so long as they are below the water table and not exposed to the air. The problem is that concrete construction projects can create precisely these conditions, particularly if new foundations are being dug.

When sulphates – which are also known as sulfates – are present, they can lead to an adverse reaction with tricalcium aluminate, one of the key ingredients of the cement contained within concrete.

What Damage Can It Do?

When sulphates and tricalcium aluminate react, they force the cement admixture to expand, destroying the paste which gives the concrete its adhesive qualities. Over time the concrete will crack and spall, and eventually lose much of its overall strength. This can be a big issue if your concrete is part of a load-bearing surface, such as a sub-base or foundation.

What’s the Solution?

The simplest way of ensuring your concrete isn’t affected by this type of reaction is to purchase a sulphate-resistant admixture. This contains a lower percentage of tricalcium aluminate, lessening the chance of any short or long-term damage to the concrete. Another method of creating this admixture is to increase the amount of fly ash – a waste product from coal-fired power stations – in the cement.

Sulphate-resistant concrete is ideal for projects where both water and chemicals are likely to be present, such as sewers, water storage areas and treatment works. Many seawalls, bridges and piers are built with this type of admixture, which is also ideal for any underground construction schemes.

Sulphate-Resistant Concrete from Madmix

Sulphate-resistant concrete is one of the admixtures we can offer to homes and businesses near Newmarket, as well Haverhill, St Neots, St Ives and Cambridge.

Other admixture varieties we offer include waterproof concrete, pumpable concrete, a lower-strength lean/kerb mix, plus concrete which has been reinforced with polypropylene fibres. If you are not sure which type is best for your project, contact us and we will be happy to advise you. You can get in touch by following this link and filling in the online form, calling us on 01954 212212 or emailing us at

All our concrete is accredited, which means it undergoes regular, stringent testing and is guaranteed to be of extremely high quality.

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