Sun Yubo, Liu Zhiyuan, Ghorbani Saeid, Ye Guang, De Schutter Geert
Magnel-Vandepitte Laboratory, Department of Structural Engineering and Building Materials, Ghent University, 9052, Ghent, Belgium.
Microlab, Section of Materials and Environment, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628, CN Delft, the Netherlands.
J Clean Prod. 2022 Oct 10;370:133362. doi: 10.1016/j.jclepro.2022.133362.
The present study explores the possibility of replacing blast furnace slag (BFS) with coal fly ash (FA) to produce alkali-activated material (AAM) concrete with hybrid precursors. With an increased FA replacement ratio, the reaction kinetics, fresh and hardened properties of AAM mixtures have been investigated. The retardation effect on the reaction kinetics with an increased FA content has been observed, which not only extended the induction period along with the heat flow evolution but also reduced the cumulative heat release up to 24 h. Spherical FA particles can provide a ball-bearing effect to improve the workability of the hybrid AAM mixtures, while FA also slows down the deterioration of fresh properties since they are less reactive compared to BFS particles. Regarding the strength development, FA results in the reduction at all curing ages in the mixtures with a low silicate modulus (Ms0.25). Similarly, reduction in 1-day compressive strength has been detected in high silicate modulus mixtures (Ms0.5) with FA replacement, while the mixture with 10% FA exhibits the highest compressive strength among Ms0.5 concretes at later curing ages. Bigger capillary pores have been detected in AAM mixtures with an increase in FA content. However, AAM with 10% FA shows the lowest porosity in Ms0.5 mixtures, which is in agreement with the compressive strength results.
本研究探讨了用粉煤灰（FA）替代高炉矿渣（BFS）以生产具有混合前驱体的碱激活材料（AAM）混凝土的可能性。随着FA替代率的增加，对AAM混合物的反应动力学、新拌性能和硬化性能进行了研究。观察到随着FA含量增加对反应动力学的延缓作用，这不仅随着热流演变延长了诱导期，还降低了24小时内的累积热量释放。球形FA颗粒可提供滚珠效应，提高混合AAM混合物的工作性，同时FA也减缓了新拌性能的劣化，因为它们与BFS颗粒相比反应性较低。关于强度发展，在低硅灰比（Ms<0.25）的混合物中，FA导致所有养护龄期的强度降低。同样，在高硅灰比（Ms>0.5）且用FA替代的混合物中，检测到1天抗压强度降低，而在Ms>0.5的混凝土中，含10%FA的混合物在后期养护龄期表现出最高的抗压强度。在FA含量增加的AAM混合物中检测到更大的毛细孔。然而，含10%FA的AAM在Ms>0.5的混合物中孔隙率最低，这与抗压强度结果一致。
