| 摘要: |
| 利用超细粉煤灰部分取代Ⅰ级粉煤灰，在常温条件下制备碱激发粉煤灰（AAFA）胶凝材料，并采用减水剂对其流动性能进行优化.结果表明：超细粉煤灰掺量为50%的AAFA浆体初凝时间为42 min，3 d抗压强度为12.78 MPa，但表观黏度太大，导致常规试验无法测出其流动度值；萘系减水剂可增强AAFA浆体中粉煤灰颗粒的分散程度，大幅降低浆体的表观黏度，显著提高其初始流动度及流动度保持率，但会包裹粉煤灰颗粒并弱化凝胶产物间的连接，延长AAFA浆体的凝结时间，并对其早龄期抗压强度产生不利影响；萘系-三聚氰胺复合减水剂亦可显著降低AAFA浆体的初始表观黏度，提升其初始流动度，同时影响浆体的聚合反应进程，对其抗压强度发展产生一定促进作用，但导致浆体流动度损失加大. |
| 关键词: 碱激发粉煤灰胶凝材料 超细粉煤灰 减水剂 常温性能 |
| DOI：10.3969/j.issn.1007-9629.2023.04.012 |
| 分类号:TQ536.4 |
| 基金项目:固废资源化利用与节能建材国家重点实验室开放基金资助项目（SWR-2021-009）；陕西省科学技术研究计划（2021GY-203，2022GY-418，2022KXJ-008）；陕西省教育厅重点研发计划（20JS079，20JY040）；先进土木工程材料教育部重点实验室（同济大学）开放基金资助项目（202104） |
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| Effect of Ultra-fine Fly Ash and Superplasticizer on Properties of Alkali-Activated Fly Ash Binder at Room Temperature |
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ZHU Huimei1,2,3, ZHANG Yuwen1, LI Hui1,2,3
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1.College of Materials Science and Engineering， Xi'an University of Architecture and Technology， Xi'an 710055， China;2.Ecological Cement Engineering Research Center of Ministry of Education， Xi'an University of Architecture and Technology， Xi'an 710055， China;3.Shaanxi Ecological Cement & Concrete Engineering Technology Research Center， Xi'an University of Architecture and Technology， Xi'an 710055， China
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| Abstract: |
| Alkali-activated fly ash （AAFA） binder was prepared with ultra-fine fly ash partially replacing Class Ⅰ fly ash at room temperature， and its flowability was optimized by superplasticizer. The results show that the initial setting time of AAFA paste with 50% ultra-fine fly ash is 42 min， and the 3 d compressive strength is 12.78 MPa. As the apparent viscosity is too large to make it possible to test its fluidity value in conventional tests， naphthalene superplasticizer is added to enhance the dispersion of fly ash particles in AAFA paste， with the result that it significantly reduced the apparent viscosity， and thus improves the initial fluidity and fluidity retention of the paste. However， as the fly ash particles are encapsulated and the connection between the gel products is weakened， the setting time of the AAFA paste is prolonged so as to be unfavorable to the compressive strength of the early age. Naphthalene-melamine composite superplasticizer also significantly reduced the initial apparent viscosity of AAFA paste and improved its initial fluidity. Moreover， due to its influence on the polymerization process， the development of compressive strength of AAFA paste is promoted， while the fluidity loss is accelerated. |
| Key words: alkali-activated fly ash （AAFA）binder ultra-fine fly ash superplasticizer property at room temperature |
