The application of a combination of treated AMPS/IA copolymer and borax as the retarder of calcium aluminate phosphate cement

- Sodium hexametaphosphate negatively affect retarding effect of conventional retarder.
- AMPS/IA copolymer could extend the thickening time of CAPC.
- Treated AMPS/IA copolymer could avoid the consistency fluctuation of CAPC.
- The combination of treated copolymer and borax is suitable as retarder for CAPC.

The research objectives in this paper are designed to develop one new type of retarder for calcium aluminate phosphate cement (CAPC) to extend the thickening time. Results show that due to the influence of sodium hexametaphosphate, many kinds of conventional Portland cement retarder lose the retarding function in CAPC. AMPS/IA copolymer could extend the thickening time obviously; however, the thickening curves show consistency fluctuations. Although, treated AMPS/IA copolymer could avoid the consistency fluctuation, right angle thickening property is weak. Due to the synergistic effect, the combination of treated AMPS/IA copolymer and borax is more suitable as the retarder for CAPC.