Influence of PCE-type GA on cement hydration performances

Abstract

Modified polycarboxylate-type (PCE-type) grinding aid (GA) by grafting acylamino group and hydroxyl group into the backbone of PCE polymer was synthesized, and its possibility to be adopted as cement GA was estimated in this research. The grindability of PCE-type GA was measured in terms of grinding duration as well as particle size distribution, and the grindability of PCE-type GA was systematically compared with that of triethanolamine (TEA) and ordinary PCE-type superplasticizer. The cement hydration kinetics, the microstructure, and the physical–mechanical properties of ground cement samples in the function of PCE-based GA were analyzed. The results indicated that PCE-type GA was more effective in cement grinding process than TEA as well as PCE-type superplasticizer, exhibiting shortened grinding duration, optimized particle size distribution, and homogenized particle morphology. And cement ground by PCE-type GA was characterized with lower water demand, higher fluidity property, and increased mechanical strength, ascribed to the dispersion capability of PCE polymer as well as the unified cement particle size distribution. The application of PCE-type GA could slightly prolong the induction period of the ground cement, but gently enhance the hydration degree. Lower porosity and denser microstructure with higher density of cement hydration products uniformly distributing in the hardened matrix could be achieved with PCE-type GA adopted in the ground cement.