改性甘蔗渣缓凝剂的性能及机理分析

Performances and mechanism analysis of modified bagasse retarder

摘要:

通过亚氯酸钠预处理和在磷钨酸催化条件下复合酸酸解的方法改性甘蔗渣，制备出改性甘蔗渣缓凝剂（MBR），采用FTIR对其进行结构表征，通过水化热、XRD和SEM分析其对水泥水化的影响。分别在20和50 ℃下，对比了其与葡萄糖酸钠（SG）的缓凝效果。结果表明，MBR中含有羟基、羧基和磷酸基官能团，与水泥的适应性良好，缓凝性能优于SG且不影响混凝土后期强度，能够延缓诱导期，降低加速期的水化速率。

Abstract:

Modified bagasse retarder (MBR) was prepared by sodium chlorite pretreatment and acid hydrolysis of bagasse in the presence of a catalytic amount of phosphotungstic acid, and its functional groups were analyzed by FT-IR, the influence of hydration heat, XRD and SEM on cement hydration was analyzed, and the retarding effect was compared with that of sodium gluconate (SG) at 20 °C and 50 °C, respectively, MBR contains hydroxyl group, carboxyl group and phosphate group, which has good adaptability to cement, better retarding performance than SG and does not affect the later strength of concrete, which can delay the induction period and reduce the hydration rate in accelerating period.