Product Catalogue: Cement

Special Purpose Cement


Blue Circle® Special Purpose Cement complies with AS 3972-1997, Type LH/SR. It is manufactured from the ingredients of specially selected cement clinker and ground granulated blast furnace slag, combining the benefits of significantly lower heat evolution, greater sulphate, chloride and salt water resistance.

    Features & Benefits

  • An engineered cement conforming to AS 3972 types LH and SR.
  • Uses: Environments where a Low Heat, Sulphate Resisting or Marine cement is required (developing strength at a later age).

State Availability

NSW, 
ACT, 
VIC

Product Range

Bagged Cement

Application / Use

Sulphate Resistance, 
Low Heat Applications, 
Marine Applications

Type 

Blended Cements


Uses
Blue Circle® Special Purpose Cement may be used in marine applications, in mass concrete where reduced heat liberation is important or in aggressive sulphate-rich environments where increased resistance to salt attack is required. Where concrete is expected to be in contact with sulphates or other aggressive salts or solutions, analytical surveys must be completed and appropriate grade of concrete selected. As with Portland cements, the resistance to acid solutions is limited, but concrete life expectancy will be maximised by using Blue Circle® Special Purpose Cement at high cement content and low water to cement ratio in fully compacted and cured concrete.


Properties
The performance of the cement when tested using Australian Standard test methods under standard conditions will typically be within these ranges.
 

Special Purpose Cement   AS 3972LH/SR
Setting Time: Typical: Requirement:
Initial 2-4 hours 45 min
Final 3-5 hours 10hrs max
Soundness: 1.0mm 5mm max
Sulphate Resist. 150-250mstrain 900mstrain max
Peak Temp. Rise 19-23 deg.C 23 deg. C
Compressive Strength:    
Mortar Prism:    
7 Day 25 - 33 MPa 20MPa Min
28 Day 50 - 60 MPa 35MPa Min



Compatibility
Blending with other products is not recommended as this may adversely influence the resistance of concrete to chemical attack and alter the heat evolution properties. Blue Circle® Special Purpose Cement is compatible with admixtures complying with AS 1478.


Sulphate Resistance
The Sulphate Resistance Test is based on the expansion of a thin mortar bar soaked in a sodium sulphate solution. Australian Standard AS 3972 specifies an upper limit of 900 microstrain expansion for Type SR cement. Typically, Blue Circle® Special Purpose Cement mortar bar expansion is below 250 microstrain. The following graph demonstrates the SR performance of Blue Circle® Special Purpose Cement relative to a Blue Circle® General Purpose cement.


Sulphate Resistance of LH/SR & Blue Circle® Special Purpose Cement
Sulphate resistance graph


Heat Evolution
Australian Standard AS 3972 limits the peak temperature rise of Type LH cement to below 23 degrees when tested in accordance with AS 2350.7 – Langavant Test. Blue Circle® Special Purpose Cement complies with AS3972 for a low heat cement and the peak temperature rise is significantly lower than conventional Portland cements.

The following graph demonstrates the heat evolution of Blue Circle® Shrinkage Limited (SL), High Early Strength (HES) and Blue Circle® Special Purpose Cements.

Heat evolution over time
Heat evolution graph


Concrete Properties
The composition of Blue Circle® Special Purpose Cement is formulated to deliver lower heat of hydration and superior sulphate resistance. This results in slower strength development by the Blue Circle® Special Purpose Cement, with significantly lower early age strength, but a greater potential for later age strength development. Typically the early age strength of concrete containing Blue Circle® Special Purpose Cement may be half that of similar concrete containing General Purpose cement at the same water to cement ratio, but the later age strength will not be significantly lower.

Special purpose strength development


Effect of Excess Water
Use only the minimum amount of water to mix and place concrete. Excess water will have a detrimental effect on the compressive strength and other properties of concrete. The following graph shows the reduction in concrete strength with increased water addition.

Other factors that will influence the strength and durability of concrete containing Blue Circle® Special Purpose Cement are:

• Mix design, including admixtures
• Temperature – ambient and that of materials
• Air content
• Compaction of concrete
• Curing of concrete


Effect of Addition of Excess Water on Concrete Strength & Slump
Effect of Addition of Excess Water graph


Mix Design
Dense, fully compacted concrete of low permeability is essential to minimise the aggressive effects of sulphate and chloride attack. Careful selection of mix components is essential and reference should be made to AS 1379- The Specification and Manufacture of Concrete and AS 3600 – Concrete Structures.

For site mixed concrete, the following mix design with the minimum cement content is recommended.


Mix Proportions by Volume In Low SO3 environments

Application Special Purpose Cement Stone Gravel Sand
High Strength 1 2.5 1.5
General Use 1 3 2
Foundations etc 1 4 5
Figures shown are parts by volume.



Mixing
AS 1379 gives requirements for material quality and mixing of ready-mixed concrete. Presence of salts and organic matter in aggregates and mixing water may affect concrete performance and relevant requirements of AS1379 must be observed.


Placing
The concrete should be compacted and given a suitable finish. Adequate cover to the steel reinforcement is required to avoid corrosion.


Curing
Good curing will significantly improve the compressive strength of concrete compared to concrete which is not cured.


Concrete will benefit from curing in terms of reduction in shrinkage cracking potential, improved surface quality with respect to abrasion resistance, permeability to air and water improved carbonation resistance.


Availability
Blue Circle® Special Purpose Cement is available in 20kg plastic lined, multi-walled paper sacks.


Storage
The “shelf life” of Blue Circle® Special Purpose Cement is dependent on the storage conditions, as contact with air and moisture will cause deterioration in cement performance. Cement bags are not waterproof and should be stored off the ground, in as dry an environment as possible.

It is recommended that Blue Circle® Special Purpose Cement be retested if the age of cement exceeds three months.


Safe Handling
This product contains cement chemicals and trace amounts of Hexavalent Chromium. Avoid generating dust. Use personal protection equipment against exposure and alkali burns. Wash product off unprotected skin immediately with water. The use of goggles, dust masks, barrier creams and rubber gloves is recommended.

Wherever possible, use mechanical aids or share the load with another person.

For further safety information consult the Material Safety Data Sheet for the product.

Delivery / Packaging:


20kg Bags 72 per pack