|
| 摘要: |
| 在水泥浆体中分别掺入2种含不同数量官能团共聚的羧酸系超塑化剂，比较了它们对新拌水泥浆体流动性的影响。结果表明：较大幅度地增加羧基数量并小幅度地增加磺酸基数量，就相当于增加了吸附点的数量，也就是增加了水泥颗粒表面对超塑化剂的吸附能力，从而使得液相中超塑化剂量减少，分散能力减弱；较大幅度地减少羟基数量，可相对加速水泥的水化过程，从而加速水泥颗粒对超塑化剂的吸附；羧基数量的大幅度增加所造成的正面作用(Zeta电位绝对值增加、缓凝作用增加)小于负面作用(吸附点的增加)。 |
| 关键词: 超塑化剂 共聚羧酸 流动性 吸附 水泥净浆 |
| DOI： |
| 分类号:TU528.042 |
| 基金项目:北京大学北京绿色前缘技术创新中心创新基金资助项目 |
|
| Effects of Polycarboxylic Acids Superplasticizer on Fluidity of Cement Paste |
|
ZUO Yan-feng WANG Dong-min WU Shao-zu
|
| Abstract: |
| The test method of cement paste fluidity is adopted. The test of cement pastes fluidity was made in which two types of polycarboxylic acids superplasticizers were added. The test results show that a great increase of carboxyl and a slight increase of sulfonic groups in molecule can increase adsorption points and this enhances adsorptive ability and lowers the concentration of superplasticizer in aqueous phase, thus, the dispersion ability decreases; a significant decrease of hydroxyl groups accelerates hydration process comparatively making the adsorption process easier; the positive effect of the great increase of carboxyl (increase of absolute Zeta potential and retardation effect) is smaller than the negative effect(increase of adsorption point). |
| Key words: superplasticizer,polycarboxylic acids,fluidity,adsorption,cement paste |
