Hydration behavior of magnesium potassium phosphate cement and stability analysis of its hydration products through thermodynamic modeling

Magnesium potassium phosphate cement (MKPC) is normally applied in civil engineering because of its short setting time and superior mechanical properties. This study investigates the hydration behavior and hydration products of MKPC influenced by molar ratio between magnesia and phosphate (M/P ratio) through thermodynamic method. Results show that the composition of ultimate hydration products are controlled by concentration of KH₂PO₄ and MgO, activity of water and pH value of solution. When M/P ratio is lower than 0.64, the hydration product is MgHPO₄·3H₂O; When M/P ratio is between 0.64 and 0.67, the hydration products are MgHPO₄·3H₂O and Mg₂KH(PO₄)₂·15H₂O. When M/P ratio is between 0.67 and 1.00, hydration products are Mg₂KH(PO₄)₂·15H₂O and KMgPO₄·6H₂O; When M/P ratio is higher than 1.00, the hydration product is KMgPO₄·6H₂O together with unreacted MgO. This study also investigated the effect of additives, namely B(OH)₃, H₃PO₄, K₂HPO₄ and KH₂PO₄.

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01637924
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 16 2017 4:41PM