富铁钛石膏做水泥缓凝剂的试验研究

Experimental Research on Cement Retarder by Titanium Gypsum with Iron in Rich

利用钛石膏单掺、钛石膏与天然石膏复掺制备P·Ⅰ型水泥研究钛石膏作水泥缓凝剂的可行性。对制备的P·Ⅰ型水泥进行了物理力学性能和水化放热特性研究，通过XRD、SEM对水泥水化产物的物相和微观形貌进行了分析。研究结果表明．单掺钛石膏会增大水泥标准稠度用水量，缩短凝结时间，但其强度与单掺天然石膏试样强度相当：对于钛石膏和天然石膏复掺的水泥，随着钛石膏掺量增加，其标准稠度用水量增加，凝结时间先增大后减小．在钛石膏掺量为2．50％时凝结时间最长，强度均先增加后减小，在钛石膏掺量为1．25％-3．75％时，试样28d抗压强度均高于对照组。掺加钛石膏的水泥安定性合格，标准稠度用水量、凝结时间和强度均符合标准要求。

P·Ⅰ cement was prepared by using titanium gypsum and a mixture of titanium gypsum and natural gypsum to study the possibility of making use of titanium gypsum as setting retarders. The basic physical properties and hydration heat characteristics of P·Ⅰ cement were studied. The phases and microstructureg of cement hydration products were investigated by XRD and SEM. The results showed that adding titanium gypsum would increase normal consistency, shorten the setting time, and its strength is same as which using natural gypsum. With the increase of dosage of titanium gypsum, the normal consistency of double mixed titanium gypsum and natural gypsum cement increase, and the setting time first increases then decreases. When the titanium gypsum dosage is 2.50%, the setting time reached longest, as the dosage increased from 1.25% to 3.75%, its 28d compressive strength is higher than the control group. The soundness of P·Ⅰ cement with titanium gypsum could meet the demand, the setting time, normal consistency and strength are conform to the standard.