Calcium sulfoaluminate: modified Portland cement

Calcium sulfoaluminate modified Portland cements may be produced by combining ordinary Portland clinker with limited amoimts of calcium sulfoaluminate, produced separately (see section 21.3), and calcium sulfate. 

For additional data on calcium sulfoaluminate-modified Portland cements see section 4.4. 

While sulfoaluminate-modified Portland cements that contain limited amounts of C4A3 S and calcium sulfate exhibit no expansion, those with higher amounts of these phases expand and are used as expansive cements (type K see section 21.3). 

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