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High Efficiency CSA Expansive Agent

High-efficiency CSA expansive agent is obtained by blending suitable natural anhydrite with a specially manufactured clinker which consists essentially of calcium sulphoaluminate and CaO. CSA expansive agent is always mixed with ordinary cement. When mixed in the proper proportions with ordinary cement and hydrated, cement mortar or concrete expands during the early stages of hydration. This expansion, when restrained, makes it possible to minimize drying shrinkage. Moreover, when the ratio of shrinkage reducing admixture to ordinary cement is increased its high expansion qualities make it ideal for use in prestressed concrete.


High-efficiency shrinkage reducing admixture is being used in all sections of the construction fields and by a wide variety of concrete products manufacturers.

Chemical Analysis:


Physical Properties:



  • Low alkalinity. High-efficiency CSA Expansive Agent has a very low alkali content (R2O<0.3%) which is beneficial to avoid Aggregate Reaction (AAR) in concrete.

  • Short stable stage of expansion. The stable stage of expansion is not more than 14 days, thus the ultimate strength of concrete is not affected.

  • Low dosage and high expansion capacity. The normal dosage of High-efficiency CSA Expansive Agent is 6-8% by the weight of ordinary cement, which is lower compared with other expansive additives such as UEA and CEA (their dosages are about 10-12% by the weight of cement) in the market.

  • Prevents cracking due to drying shrinkage and hydration heats.

  • Increases the water tightness of concrete and thus is useful for waterproofing buildings.

  • Enables the manufacture of high strength concrete products through chemical prestressing.

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