Effect of phosphate ester grinding aids on cement grinding and water-reducing performance

Phosphate ester polymers were prepared from phosphate ester monomers for the first time and their effects as cement grinding aids and water-reducing performance were studied. Fourier-transform infrared (FTIR) spectroscopy and tests for standard viscosity, setting time, mortar fluidity, mortar compressive strength were conducted. The results showed that hydroxyethyl dibutyl phosphate reduced the residues of 45 μm and 80 μm grinding sieves by 68.67% and 98.67%, respectively. Compared with triethanolamine, the grinding effect of hydroxyethyl dibutyl phosphate was not only better but also the optimal mixing amount was less (only 0.167%). For the same amount of grinder, the grinding time was shortened by 30% and, for the same grinding time, the grinding output was increased by at least 20%. The polymer grinding aids significantly improved the fluidity of cement paste (by 40.06%), meaning the water-reduction rate of cement mortar could reach over 20%. The experimental results show that, as a new generation of grinding aids, phosphate esters not only have a significant grinding effect but also have high molecular designability, which will significantly enrich the grinding aids market and effectively promote energy conservation and emissions reductions in the grinding process.