CSA Binder

CSA Cement, also named Calcium Sulpho Aluminate Cement with grade: 42.5, 52.5, 62.5, 72.5, 82.5, 92.5, is a hydraulic binder based on calcium sulpho aluminate, rather than calcium aluminates which are the basis of Calcium Aluminates Cement or calcium silicates which are the basis of Portland Cement. It can be used on its own (with a Lithium accelerator), or with an Anhydrite, Portland cement mix, Metakaolin or a combination of all.

CSA Cement has the benefit of being readily adaptable to suit many different applications where both rapid set and / or high early strength gain are required. It yields controlled set, enhanced early strengths, shrinkage compensation or expansion and sulphate resistance. Uses include any cement-based product in need of these properties. CSA Cement products exhibit a range of properties to suit a wide spectrum of cement-based applications, like fast setting cements, self-leveling or self-smoothing compounds, self compacting concrete, rapid hardening mortars, tile adhesives, non-shrink grouts, water stopping mortars, repair mortars, high early strength concrete, GRC, etc.

Within CSA (Calcium Sulpho Aluminate) Cement Ettringite formation is typical. Ettringite is an expansive crystalline substance formed when sulphate reacts with tri-calcium aluminate (C3A) and calcium hydroxide (Ca(OH)2). It occupies twice the volume of the original compounds so an expansion occurs. In the CSA Cement, 85% of ettringite is developed at a very early stage in the process, before the aluminates and silicates start to hydrate. The risk of late ettringite formation is very limited and the ettringite which is formed is very stable over time. This is the fundamental difference between CSA and CAC (Calcium Aluminate Cement) Cement.

Be it a mortar or a concrete, making a composite cement which exhibits rapid setting, high early strength development, with little or no loss of late strength, no risk of conversion or late formation of ettringite. Depending on the level of addition of calcium sulphate, either shrinkage compensation or positive expansion can also be controlled.

Potential advantages of the CSA Cements are low CO2 emissions, improved sulphate resistance, low permeability, enhance durability and a good workability at low temperatures.

Properties
Incorporation of Calcium Sulpho Aluminated Cement into a variety of mix designs, CSA Cement products exhibit a range of properties, like:

Rapid Set Adjustable Setting Time High Early Strength
Increased strength in time Minimal Shrinkage Shrinkage compensation
Expansion Sulphate Resistance Reduced Alkalinity
Low CO2 Emissions Rheology Adapted to the Application, etc.

Fineness
Specific Surface Area: According to standard GB/T 8074-2008:
Usual range: 400(+/-20) m2/kg, Specification limit: >360 m2/kg;
Usual range: ≥ 480 m2/kg, Specification limit: >450 m2/kg.
 
Setting time Initial ≥ 25min ≥ 25min ≥ 25min
Final ≤ 300min ≤ 300min ≤ 300min

Reactivity with Portland cement

CSA Binder may be used in combination with other mineral products, for example
Portland cement, calcium sulphates and fillers, or with organics such as polymers in latex
foam or in redispersiblefoam.

Depending on the type of mixes and technology employed, CSA Binder can be used to
obtain and control various properties.

The behavior of Portland cement is vary variable. In general, acceleration of set increases
progressively with the addition of CSA Binder. The amount of CSA Binder needed to
obtain a specific setting time varies considerably depending on the origin of the Portland
cement and performance can be modified with the use of additives.

The strength development of CSA Binder/Portland cement and/or Calcium Sulphates
depend on the nature of the Portland cement and/or Calcium Sulphates used. In general
these mixes will develop mechanical strength at a very early stage (several hours). With
some type of Portland cements and in formulated products containing additives which
control the setting and hydration, the long term properties is similar to those of the original
Portland cement, however it is necessary to check the behavior of each Portland cement
used.

The characteristics of Portland cement to be considered are:
C3A content
Mineral admixture type and content
Type of Calcium Sulphate used
Additives will also influence the properties of these mixes:
Setting time
Rheology
Mechanical performance

Applications
These properties are applied to obtain a wide range of products:
- Rapid repair mortars
- Fast setting tile adhesives
- Fast setting tile grouts
- Shot-crete / Gun-nite
- External renders
- Self smoothing mortars
- Self leveling mortars
- Anchor bolt grouts
- Non shrinking grouts
- etc.

With a careful selection of the constituents (OPC, calcium sulphates, additives), it is
possible to create mixes with a range of different hydraulic properties:
Adjustable setting time
Rheology adapted to the application
High early strength
High long term strength
Shrinkage compensation

Use of Additives

CSA Cement may be used in combination with chemical additives such as:
- polymers, either in latex form or redispersible powder form
- defoamers
- retarders
- accelerators
- plasticizers/superplasticizers
- rheology modifiers
- fibers

Please contact me for more product information.