CALCIUM SULFOALUMINATE (CSA) BINDER
Calcium Sulfoaluminate (CSA) Binder
CSA = Calcium Sulfo Aluminate = Calcium Sulfoaluminate
Calcium Sulfoaluminate Cement Binder = Calcium Sulfoaluminate CSA Binder = CSA Binder
Calcium Sulfoaluminate CSA Binder is a hydraulic binder based on calcium sulphoaluminate rather than calcium aluminates, which are the basis of Calcium Aluminates Cement, or calcium silicates, which are the basis of Portland Cement.
The difference gives Calcium Sulfoaluminate CSA Binder properties particularly suited to formulators of products such as self-leveling or self-smoothing compounds, rapid hardening screeds, tile adhesives, non-shrink grouts, rapid setting, and special mortars.
Calcium Sulfoaluminate CSA Binder is used in formulated products as a hydraulic binder by itself, with the addition of calcium sulfates, or in combination with Portland cement.
The setting time is quicker than that of Portland cement and has a rapid strength development.
Calcium Sulfoaluminate-based CSA Binder does not release free lime during hydration, thus eliminating the primary cause of efflorescence
Calcium Sulfoaluminate CSA Binder is Calcium Sulfoaluminate Binder for Portland Cement.
Calcium Sulfonuminate-based CSA Binder is a cement hydraulic binder based on calcium aluminate sulfate.
The setting time is quicker than ordinary Portland cement (OPC), and it does not release free lime during hydration, decreasing efflorescence.
Calcium sulfoaluminate-based CSA Binder accelerates the set time and strength of Portland cement, compensates for shrinkage, and adapts the rheology to the application.
Characteristics of Calcium Sulfoaluminate CSA Binder
Resistant to sulfate attack
Impermeable
Short curing phase
Freeze-thaw resistant
Uses of Calcium Sulfoaluminate CSA Binder
CSA cement has been used as a binder in airport runaways, concrete road repair, concrete bridges, and many other applications where fast reuse is needed.
Applications of Calcium Sulfoaluminate CSA Binder
These properties are applied to obtain a wide range of products:
Fast setting cement
Rapid hardening mortars
Tile adhesives
Self-leveling compounds
Non-shrink grouts
Water stopping mortars
With a careful selection of the constituents (OPC, calcium sulfates, 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
Calcium Sulfoaluminate Cement Binder may be used in combination with chemical additives such as:
polymers, either in latex form or re-dispersible powder form
Defoamers
Retarders
Accelerators
Plasticizers/superplasticizers
Rheology modifiers
Fibers, etc
Calcium Sulfoaluminate Cement Binder also has properties that make it suitable for formulating:
Self-smoothing and self-leveling compounds
Tile adhesives
Casting mortars
Rapid hardening screeds
Non-shrink grouts
Mining products such as mining roof support materials
Glass fiber reinforced concrete
Benefits of Calcium Sulfoaluminate Cement Binder
Rapid Strength Development
When CSA is added to mortars or concrete, it significantly increases its strength development.
It takes 24 hours for concrete and mortars with a Calcium sulfate-based Cement Binder to achieve the same strength OPC achieves in 28 days.
Fast Bond
The original setting time can begin after twenty minutes, and the final set can be reached after 30 minutes.
The processing time can be extended even further using retarders.
CSA also maintains its reactivity under low temperatures, unlike other binders.
Shrinkage Compensation
Several criteria demonstrate the shrinkage compensation of CSA.
They include:
CSA requires more water than Portland cement.
However, there is no water surplus since the water is fully chemically bound.
The water surplus with other binder types causes shrinkage, warping, and cracking.
There is a stable expansion that occurs during the hardening phase.
It helps prevent gradual shrinkage.
The tension during hydration builds up in a shorter timeframe than typical cement types.
Low Carbon Footprint
CSA is regarded as a green binder due to the following reasons:
CSA is softer compared to Portland cement.
This reduces the amount of energy required during grinding.
CSA is calcined at 2250°F while Portland cement is calcined at 2700°F.
Portland cement production is estimated to be responsible for about 8% of worldwide carbon dioxide emissions.
For every 1000kgs of Portland cement, approximately 579kg of carbon dioxide is emitted.
The production of Calcium sulfoaluminate-based Cement Binder has the lowest carbon dioxide emission compared to the production of alternatives such as sodium metasilicate, magnesium, and calcium aluminate cement.
Reactivity with Portland cement
Calcium Sulfoaluminate Cement Binder may be combined with other mineral products, such as Portland cement, calcium sulfates, fillers, or organics, such as polymers in latex or re-dispersible foam.
Depending on the type of mixes and technology employed, Calcium Sulfoaluminate Cement Binder can be used to obtain and control various properties.
The behavior of Portland cement varies.
In general, the acceleration of the set increases progressively with the addition of the Calcium Sulfoaluminate CSA Binder.
The amount of Calcium Sulfoaluminate 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 additives.
The strength development of Calcium Sulfoaluminate CSA Binder/Portland cement and/or Calcium Sulphates depends on the nature of the Portland cement and/or Calcium Sulphates used.
These mixes will generally develop mechanical strength very early (several hours).
With some Portland cement and formulated products containing additives that control the setting and hydration, the long-term properties are 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
The kind of Calcium Sulphate used
Additives will also influence the properties of these mixes:
Setting time
Rheology
Mechanical performance