School of Civil and Environmental Engineering, Yonsei University, Yonsei-Ro 50, Seodaemun-Gu, Seoul, 03722, South Korea.
Architectural Engineering Program, School of Architecture, Seoul National University of Science and Technology, 232 Gongneung-Ro, Gongneung-Dong, Nowon-Gu, Seoul, 01811, South Korea.
Environ Sci Pollut Res Int. 2024 Nov;31(52):61437-61450. doi: 10.1007/s11356-024-35250-1. Epub 2024 Oct 18.
The coal-fired power plant fly ash (FA) and bottom ash (BA) are gradually used as alternative materials in the concrete. However, knowledge of the leaching characteristics of using both incinerator ashes in concrete production is lacking. This work aimed to evaluate the leaching behavior of the FA and BA used in concrete production by employing batch and tank leaching tests. The outcomes of both leaching tests showed that there was no considerable leaching of any trace elements to the environment, and it remains much lower than standard limitations for utilization as construction materials. The results of cumulative mass discharge showed that the slope of flux time for all elements was less than 0.4 and because of that, primary surface wash-off was the main discharge process of all the heavy metals. Strength test results revealed that there was not much difference between coal ash concrete (CAC) and the control mix at the initial age of curing time. Despite that, at a long period of curing time (180 days), the compressive strength of CAC containing 20% FA as cement replacement and 100% BA as fine aggregate replacement increased by 76% due to the pozzolanic reaction of BA and FA in comparison to the normal concrete, while, due to the high porosity of BA, the workability of CAC decreased by 50%. The outcomes of the current work revealed that the combined use of FA and BA can be counted as a promising alternative in the production of sustainable concrete for structural applications toward sustainable development.
燃煤电厂粉煤灰（FA）和底灰（BA）逐渐被用作混凝土的替代材料。然而，对于在混凝土生产中使用这两种焚烧灰的浸出特性，人们的了解还很有限。本工作旨在通过批量和罐式浸出试验来评估用于混凝土生产的 FA 和 BA 的浸出行为。两种浸出试验的结果表明，没有任何痕量元素大量浸出到环境中，而且仍然远低于作为建筑材料利用的标准限制。累积质量排放的结果表明，所有元素的通量时间斜率均小于 0.4，因此，主要是表面冲刷是所有重金属的主要排放过程。强度测试结果表明，在初始养护时间，粉煤灰混凝土（CAC）与对照混合物之间没有太大差异。尽管如此，在较长的养护时间（180 天）下，由于 BA 和 FA 的火山灰反应，含有 20%FA 替代水泥和 100%BA 替代细骨料的 CAC 的抗压强度增加了 76%，而由于 BA 的高孔隙率，CAC 的工作性降低了 50%。本工作的结果表明，FA 和 BA 的联合使用可以被视为一种有前途的替代方法，用于生产可持续的结构混凝土，以实现可持续发展。
