Influence of Sucrose on Hydration Process of Portland Cement

Abstract

The sucrose (0.045%) is added in the cement paste, the consistency of Ca2+ and OH- reduce little, the AFt has high solubility product, thus the AFt exists as gel like product which covers the surface of the clinker particles, the sucrose acts as a retarder. When the dosage of the sucrose is 0.24%, the sucrose poisons the hydration of C2S and C3S markedly, so the consistency of Ca2+ and OH- reduce sharply, the AFt has low solubility product, the needle like AFt form a hydration product network and accelerates the setting process, C2S and C3S cannot yield enough C-S-H, the strength development is baffled. It was supposed that there are two dosage threshold values of sucrose on the hydration process, 0.01% is a retardation threshold value accelerating the formation of Aft, while 0.2% is an acceleration threshold value poisoning the hydration of C3S and C2S.

Effect of single water adsorption on the bond order of calcium silicates and its implication for hydration variation

“…The hydration of dicalcium silicate (Ca 2 SiO 4 , C 2 S, 15−30 wt%) and tricalcium silicate (Ca 3 SiO 5 , C 3 S, 50−70 wt%), which are the main components of Portland cement, directly influences the development of material strength 11–16 . The difference in the hydration reactivities of C 2 S and C 3 S has been the subject of many investigations 17–20 . Atomic simulations have demonstrated higher accuracy than experimental observation and have been widely used in the study of cement 21 …”