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Siam City Cement (Lanka) Limited srilanka



Certified Sulphate Resisting & Low Heat Cement

A Portland fly ash blended cement, INSEE EXTRA is Sri Lanka’s first cement to be certified for “Sulphate resistance” under the Sri Lankan (SLS) standard. INSEE EXTRA is also Sri Lanka’s first and only cement to be certified for both “Low Heat” and “Sulphate resistance” under the British (BSEN) standard, making it ideal for mass pouring concrete requirements and thick concrete constructions.

INSEE EXTRA is a result of years of research and innovation, and is manufactured with consistent quality, high-grade clinker and silica rich ‘Class F’ fly ash to significantly increase sulphate resistance and Alkali Aggregate Reaction (AAR) Resistance of concrete structures. This property makes INSEE EXTRA suitable for durable concrete structures exposed to reactive or aggressive environments. Fly ash used in the manufacturing of INSEE EXTRA also effectively increases the pumpability of concrete.

Fact File

Type : Low Heat / Sulphate Resisting Blended Hydraulic Cement
Sri Lankan Standard : SLS 1247:2015
Strength Class : 42.5N
British Standard : BS EN 197-1:2011 CEM IV/A 42.5N-LH/SR


PROPERTY SLS 1247 : 2015
(For Sulphate Resisting Cement)
Compressive Strength (2 days) ≥ 10 N/mm2 ≥ 15 Mpa
Compressive Strength (28 days) 42.5 – 62.5 N/mm2 50 Mpa
Setting Time ≥ 60 minutes 180 – 200 minutes
Fineness Not Specified in Standard 410 – 430 m2/kg
Soundness < 10 mm < 1 mm
Relative Density Not specified in standard ~ 2.98
SO3 ≤ 3.0 % >3
Chloride ≤ 0.10 % <0.08
LOI Not specified in standard <3


INSEE EXTRA is compatible with:

  • Chemical Admixtures complying with BS EN 934-1:2008
  • Fly Ash complying with BS EN 450
  • Ground Granulated Blast Furnace Slag (GGBS) complying with BS EN 15167-1:2006
  • Silica Fume complying with BS EN 13263-1:2005+A1:2009
  • Manufactured Sand (M-Sand) complying with BS EN 12620:2013
  • Natural Sand, Quarry Sand and Offshore Sand complying with BS EN 12620:2013


INSEE EXTRA is used for:

  • Concreting in aggressive environments
  • Thick concrete components such as piling, bridge piers, etc.
  • Mass concrete pouring / Temperature controlled concreting
  • Water structures / Spillways
  • Mass concrete structures where the heat of hydration effect is high
  • Concrete structures exposed to seawater (harbours, jetties, bridges, buildings etc.)
  • Concrete structures in sewerage projects (treatment plants, sewer lines, etc.)
  • Concrete in contact with water (water supply projects, irrigation structures, canal systems, dams, etc.)
  • Concrete in contact with sulphate rich soil
  • Concrete in contact with acids

Features and Benefits

Mass Pouring
Cement is the main component that is responsible for temperature development within concrete. For larger areas of concreting, high internal temperatures can cause adverse reactions such as cracking due to thermal contractions, reducing the service lifecycle of concrete structures. INSEE EXTRA is certified as a low heat cement product in adherence to British (BSEN) Standards, ensuring great reductions in internal temperature development of the structure.

Waterproof Concrete
When cement hydrates, it forms calcium-silicate hydrate gel (CSH) – which is the glue that holds the concrete together. It also forms calcium hydroxide (Ca(OH)2), and higher the proportion of CSH to Ca(OH)2 in the concrete, lower the permeability of the structure. One more functionality of fly ash in INSEE EXTRA is that it reacts with the remaining Ca(OH)2 in the concrete to form additional CSH, decreasing bleed channels, capillary channels and void spaces in the concrete, greatly reducing permeability and increasing the durability of the structure.

High Pumpability
Fly ash particles are spherical shaped and act as micro ball bearings within the concrete mix, providing a lubricant effect to the mix. This property reduces the friction during the pumping process and increases the pumpability of the concrete onto higher elevations.

Sulphate & Chloride Resistance
INSEE EXTRA is the first Sri Lankan cement product that is certified as a sulphate resisting cement. This makes INSEE EXTRA the ideal product to be used in constructions in aggressive environments that contain sulphate rich soils, salts and acids that harm and / or accelerate the decaying process of concrete structures.

Alkali Aggregate Reaction (AAR) Resistance
The silica rich ‘Class F’ fly ash used in the manufacturing of INSEE EXTRA reduces AAR by chemically reacting with alkalis in the cement and absorbing them, thereby eliminating the possibility of alkalis reacting later with potential reactive aggregates in the concrete mix.