摘要: |
系统研究了以NaOH、水玻璃以及NaOH复掺Na2CO3为激发剂,激发矿渣、粉煤灰、矿渣/粉煤灰和矿渣/水泥4种胶凝体系的凝结时间和7 d抗压强度变化规律,获得了凝结时间与掺量变化公式及早期抗压强度预测公式.结果表明:单一NaOH或水玻璃激发矿渣条件下,掺入少量粉煤灰、水泥对改善复掺体系凝结时间的效果不显著,并且均会降低早期抗压强度;采用NaOH/Na2CO3复合激发剂后,能够有效延长体系凝结时间,在一定程度上提高体系抗压强度.针对NaOH/Na2CO3复掺激发矿渣/水泥体系凝结时间和抗压强度出现“不增却减”的现象,深入讨论了掺NaOH/Na2CO3复合激发剂的作用机理. |
关键词: 碱激发 复合激发剂 矿渣/粉煤灰 凝结时间 抗压强度 |
DOI:10.3969/j.issn.1007-9629.2023.11.010 |
分类号:TU526 |
基金项目:国家自然科学基金资助项目(52322805,51978241) |
|
Variation of Setting Time and Early Age Compressive Strength of Alkali Activated System |
ZHENG Hongchen, LIU Lin
|
College of Civil and Transportation Engineering, Hohai University, Nanjing 210024, China
|
Abstract: |
Using NaOH, waterglass and a mixture of NaOH and Na2CO3 as activators, changes of setting time and 7 d compressive strength for four kinds of binding systems including alkali activated slag, fly ash, slag/fly ash and slag/cement were studied systematically, and the fitting formulas for the changes in setting time and the prediction of early age compressive strength were obtained. The results show that under the condition of single NaOH or waterglass activating slag, adding a small amount of fly ash or cement has no significant effect on the setting time, but will reduce the compressive strength at early age. NaOH/Na2CO3 compound activator can effectively prolong the setting time and improve the compressive strength to a certain extent. In addition, the setting time and compressive strength of slag/cement system activated by NaOH do not increase but decrease due to the addition of Na2CO3. The mechanism of the effect of NaOH/Na2CO3 compound activator is discussed. |
Key words: alkali activated compound activator slag/fly ash setting time compressive strength |