A residential developer was constructing a small luxury extension on a property situated close to the water in the Isle of Dogs. Initial site surveys revealed “Aggressive Ground Conditions” (Design Chemical Class DC-3) due to high levels of naturally occurring sulphates in the heavy clay soil and potential seawater seepage. Using standard C25 concrete would have led to internal expansion and structural cracking within years.

The Solution
We supplied 18m³ of Sulphate Resistant Concrete via a specialised line pump. The mix was designed using Sulphate Resistant Portland Cement (SRPC) to ensure the foundations could withstand the chemical load of the soil. Our technical team adjusted the mix with a high-performance plasticiser to ensure it remained flowable for the deep-trench pour while maintaining the low water-to-cement ratio required for chemical durability.

The Result
The project was completed on schedule with a foundation that is chemically shielded for the lifetime of the building. By selecting SRC, the developer avoided future structural failure and met all local building regulations for coastal construction.

Working Time

You typically have 60–90 minutes of workable time after delivery. This can vary depending on:

• Temperature
• Slump
• Use of admixtures (such as plasticisers used in SRC)

Plan placement efficiently, especially in warm weather to maintain the low-permeability benefits of the mix.

Temperature Considerations

• Cold weather: Sulphate Resistant Concrete may have a slightly slower strength gain in low temperatures; accelerators can help.
• Hot weather: Avoid adding water to extend workability—this increases permeability and weakens the mix’s chemical resistance.
• Frost: Protect freshly placed concrete from freezing for at least 24 hours.

Placement Tips

• Ensure the sub‑base is compacted and level.
• Use formwork to maintain shape and depth, particularly for foundations and piling.
• Vibrate lightly to remove air pockets , ensuring a dense matrix prevents sulphate ingress.
• Use a tamp or straightedge to level the surface according to your structural design.

Finishing

Sulphate Resistant Concrete can be finished to a smooth or textured surface depending on the application. For slabs and footings:

• Use a float for a smooth, dense finish that further resists chemical penetration.
• Use a brush for a slip-resistant texture if the surface remains exposed.

Curing

Sulphate Resistant Concrete benefits from:

• Light misting in hot weather to prevent plastic shrinkage cracks.
• Covering with sheeting to ensure the chemical hydration process is completed fully.
• Protection from heavy rain during the first few hours to maintain the integrity of the surface paste.

Material Reactions

Sulphate Resistant Concrete is highly specialized for chemical durability, but avoid:

• Direct contact with aluminium
• Use in highly acidic environments (pH below 4.5) without additional protective coatings.
• Mixing with standard Portland cement on-site, as this will dilute the sulphate-resistant properties of the SRPC.

Sulphate Resistant Concrete is the primary choice for structures in “aggressive” ground conditions. Its primary applications include:

Subterranean Foundations in Aggressive Soils

Sulphate Resistant Concrete is ideal for foundations supporting:

• Deep-trench footings in clay soils
• Piled foundations in tidal areas
• Structural ground beams
• Basement retaining structures
• Residential extensions on contaminated land

Its chemical composition ensures long-term stability and resistance to internal expansion and structural weakening caused by sulphate attack.

Marine and Coastal Infrastructure
Sulphate Resistant Concrete is suitable for structures that support:

• Sea walls and coastal defences
• Piers and slipways
• Harbour walls
• Promenades exposed to salt spray
• Foundations in high-saline groundwater

Its low-permeability matrix ensures long-term resistance to chloride and sulphate ingress, preventing reinforcement corrosion and surface spalling.

Wastewater and Drainage Systems
Sulphate Resistant Concrete is commonly used for infrastructure in:

• Sewerage pipes and manholes
• Septic tanks and interceptors
• Effluent treatment tanks

When used in these environments, Sulphate Resistant Concrete provides exceptional durability against chemical reactions triggered by wastewater and biological activity.

Structural Landscaping and Retaining Walls
Sulphate Resistant Concrete is ideal for:

• Large retaining walls in contact with earth
• Basements and cellar conversions
• Underground storage tanks

Its specialized cement type makes it suitable for areas exposed to constant moisture, high soil pressure, and the naturally occurring minerals found in heavy UK clays.

Industrial and Agricultural Flooring
Sulphate Resistant Concrete is often used for:

• Chemical processing plant floors
• Slurry pits and silage clamps
• Waste management facilities

Its high chemical resilience ensures long-term performance under sustained exposure to corrosive materials that would degrade standard concrete mixes.