Effect of Circulating Fluidized Bed Fly Ash on Performance of Foam Concrete

Abstract

Abstract: In order to study the effect of circulating fluidized bed (CFB) fly ash on the performance of foam concrete, two different CFB fly ash and fly ash (FA) were selected, and the compressive strength, fluidity, pore structure and water absorption of foam concrete were measured. The influences of fly ash content and type on the properties of foam concrete were studied, and the micromorphology and phase composition of foam concrete were characterized by scanning electron microscopy and X-ray diffractometer. The results show that the high sulfur calcium content and irregular particle morphology of CFB fly ash will adversely affect the working performance of foam concrete. When low sulfur calcium CFB fly ash is added, the strength of foam concrete increases with the increase of CFB fly ash content, and the compressive strength of 7 and 28 d reaches the maximum value of 1.30 and 2.25 MPa at 50% (mass fraction, the same below) content. When high sulfur calcium CFB fly ash is added, the strength of foam concrete shows a trend of increasing first and then decreasing with the increase of CFB fly ash content, and the compressive strength of 7 and 28 d reaches the maximum value at 20% and 10% content, which is 1.42 and 2.00 MPa, respectively. The ettringite and C-S-H gel generated during the hydration process of CFB fly ash can fill the pores, increase the proportion of small pores, reduce the porosity, which is beneficial to increase compressive strength and reduce water absorption of foam concrete.

Key words: foam concrete, CFB fly ash, ettringite, compressive strength, micromorphology

CLC Number:

TU528.2

CHEN Meng, ZHOU Mingkai, WANG Jie, CHEN Lishun. Effect of Circulating Fluidized Bed Fly Ash on Performance of Foam Concrete[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2023, 42(7): 2447-2457.

References

[1] 杨海瑞, BO L, RAFAL K, 等. 国际对话: “碳达峰、碳中和”背景下循环流化床锅炉的发展与挑战[J]. 电力学报, 2022, 37(2): 118-120.
YANG H R, BO L, RAFAL K, et al. International dialogue: development and challenge of circulating fluidized bed boiler under the background of “peak carbon dioxide emissions, carbon neutralization”[J]. Journal of Electric Power, 2022, 37(2): 118-120 (in Chinese).
[2] 杨蔚, 董发勤, 何平. 燃煤固硫灰渣的特性及其资源化利用现状[J]. 粉煤灰综合利用, 2013, 26(4): 50-52+56.
YANG W, DONG F Q, HE P. The characteristics and resource utilization status of coal-fired desulphurization ash residue[J]. Fly Ash Comprehensive Utilization, 2013, 26(4): 50-52+56 (in Chinese).
[3] 朱文尚. 循环流化床固硫灰特性及作水泥混合材应用的研究[D]. 北京: 中国建筑材料科学研究总院, 2011: 1-3.
ZHU W S. Study on the characteristics of sulfur-fixing ash in circulating fluidized bed and its application as cement admixture[D]. Beijing: China Building Materials Academy, 2011: 1-3 (in Chinese).
[4] 何科文, 卢忠远, 李军, 等. 循环流化床固硫灰渣性能比较研究[J]. 武汉理工大学学报, 2014, 36(3): 6-13.
HE K W, LU Z Y, LI J, et al. Comparative study on properties of circulating fluidized bed combustion ash and slag[J]. Journal of Wuhan University of Technology, 2014, 36(3): 6-13 (in Chinese).
[5] 宋远明, 钱觉时, 王智, 等. 固硫灰渣的微观结构与火山灰反应特性[J]. 硅酸盐学报, 2006, 34(12): 1542-1546.
SONG Y M, QIAN J S, WANG Z, et al. Microstructure and pozzolanic reactivity of fluidized bed combustion ashes[J]. Journal of the Chinese Ceramic Society, 2006, 34(12): 1542-1546 (in Chinese).
[6] LI D F, KE X W, ZHANG M, et al. A comprehensive mass balance model of a 550 MWe ultra-supercritical CFB boiler with internal circulation[J]. Energy, 2020, 206: 117941.
[7] MIAO M, DENG B Y, YAO X, et al. Experimental study on calcination and fragmentation characteristics of limestone in fluidized bed[J]. Journal of the Energy Institute, 2021, 95: 206-218.
[8] LIU J J, QIAO X L, FENG C Y, et al. Research on microcosmic characteristics of fly ash from circulating fluidized bed boilers[J]. Journal of the China Coal Society, 2011, 36(11): 1922-1927.
[9] JONES M R, MCCARTHY A, BOOTH A P P G. Characteristics of the ultrafine component of fly ash[J]. Fuel, 2006, 85(16): 2250-2259.
[10] 张家家, 周明凯, 李北星. CFB灰渣制备轻质混凝土的性能研究[J]. 新型建筑材料, 2020, 47(12): 10-14+74.
ZHANG J J, ZHOU M K, LI B X. Research on the performance of lightweight concrete made from CFB ash and slag[J]. New Building Materials, 2020, 47(12): 10-14+74 (in Chinese).
[11] 周明凯, 叶青, 陈潇, 等. CFB灰渣抹灰砂浆的组成设计与性能研究[J]. 硅酸盐通报, 2022, 41(2): 425-432+449.
ZHOU M K, YE Q, CHEN X, et al. Composition design and performance of CFB fly ash and CFB slag plastering mortar[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(2): 425-432+449 (in Chinese).
[12] 王杰, 王勇, 王宇强, 等. 循环流化床燃煤固硫灰的CBR特性及膨胀机理研究[J]. 硅酸盐通报, 2023, 42(4): 1323-1332.
WANG J, WANG Y, WANG Y Q, et al. Study on CBR characteristics and expansion mechanism of circulating fluidized bed fly ash[J]. Bulletin of the Chinese Ceramic Society, 2023, 42(4): 1323-1332 (in Chinese).
[13] 宋强, 张鹏, 鲍玖文, 等. 泡沫混凝土的研究进展与应用[J]. 硅酸盐学报, 2021, 49(2): 398-410.
SONG Q, ZHANG P, BAO J W, et al. Research progress and application of foam concrete[J]. Journal of the Chinese Ceramic Society, 2021, 49(2): 398-410 (in Chinese).
[14] 王静文, 刘旭照, 尹泽飞, 等. 泡沫混凝土生产应用现状与前景分析[J]. 中国建材科技, 2018, 27(6): 44-47.
WANG J W, LIU X Z, YIN Z F, et al. Present situation and prospect of production and application of foamed concrete[J]. China Building Materials Science & Technology, 2018, 27(6): 44-47 (in Chinese).
[15] 周明杰, 王娜娜, 赵晓艳, 等. 泡沫混凝土的研究和应用最新进展[J]. 混凝土, 2009(4): 104-107.
ZHOU M J, WANG N N, ZHAO X Y, et al. Latest development of research and application on foam concrete[J]. Concrete, 2009(4): 104-107 (in Chinese).
[16] 潘志华, 程麟, 李东旭, 等. 新型高性能泡沫混凝土制备技术研究[J]. 新型建筑材料, 2002, 29(5): 1-5.
PAN Z H, CHENG L, LI D X, et al. Study on preparation technology of new high performance foamed concrete[J]. New Building Materials, 2002, 29(5): 1-5 (in Chinese).
[17] ZHOU M K, CHEN P, CHEN X, et al. Study on hydration characteristics of circulating fluidized bed combustion fly ash (CFBCA)[J]. Construction and Building Materials, 2020, 251: 118993.
[18] 杨晓炳, 王永定, 高谦, 等. 利用脱硫灰渣和粉煤灰开发充填胶凝材料及在金川矿山应用[J]. 矿产综合利用, 2019(4): 130-134.
YANG X B, WANG Y D, GAO Q, et al. Research on a new cementitious materials based on desulphurization ash and fly ash and its application in Jinchuan Mine[J]. Multipurpose Utilization of Mineral Resources, 2019(4): 130-134 (in Chinese).
[19] 钱潘悦, 龚明子, 黄斌, 等. 基于图像分析技术的粉煤灰颗粒形貌表征[J/OL]. 建筑材料学报, 2022: 1-10 [2022-06-14]. https://kns.cnki.net/kcms/detail/31.1764.TU.20220613.1706.014.html.
QIAN P Y, GONG M Z, HUANG B, et al. Characterization of fly ash particle morphology based on image analysis[J/OL]. Journal of Building Materials, 2022: 1-10 [2022-06-14]. https://kns.cnki.net/kcms/detail/31.1764.TU.20220613.1706.014.html (in Chinese).
[20] 刘军, 崔云鹏, 杨元全, 等. 粉煤灰泡沫混凝土力学性能的研究[J]. 材料导报, 2014, 28(8): 139-142.
LIU J, CUI Y P, YANG Y Q, et al. Mechanical properties of foam concrete with fly ash[J]. Materials Review, 2014, 28(8): 139-142 (in Chinese).
[21] 邓最亮. 多孔和层状骨料对聚羧酸减水剂的吸附及其对砂浆流变性的影响[D]. 上海: 华东理工大学, 2021: 52-55.
DENG Z L. Adsorption of porous and layered aggregates on polycarboxylic water reducer and its influence on the rheological properties of mortar[D]. Shanghai: East China University of Science and Technology, 2021: 52-55 (in Chinese).
[22] 何燕, 张雄, 张永娟. 硫酸盐影响聚羧酸减水剂分散性的作用机理[J]. 同济大学学报(自然科学版), 2015, 43(2): 252-258.
HE Y, ZHANG X, ZHANG Y J. Effect of sulfates on dispersity of polycarboxylate superplasticizer and its mechanism[J]. Journal of Tongji University (Natural Science), 2015, 43(2): 252-258 (in Chinese).
[23] SHENG G H, LI Q, ZHAI J P. Investigation on the hydration of CFBC fly ash[J]. Fuel, 2012, 98: 61-66.
[24] SHENG G H, ZHAI J P, LI Q, et al. Utilization of fly ash coming from a CFBC boiler co-firing coal and petroleum coke in Portland cement[J]. Fuel, 2007, 86(16): 2625-2631.
[25] 袁志颖, 陈波, 陈家林, 等. 泡沫混凝土孔结构表征及其对力学性能的影响[J/OL]. 复合材料学报, 2023: 1-11 [2023-03-07]. https://doi.org/10.13801/j.cnki.fhclxb.20221014.001.
YUAN Z Y, CHEN B, CHEN J L, et al. Characterization of the pore structure of foam concrete and its influence on mechanical properties[J/OL]. Acta Materiae Compositae Sinica, 2023: 1-11 [2023-03-07]. https://doi.org/10.13801/j.cnki.fhclxb.20221014.001 (in Chinese).
[26] 赵凯月, 张鹏, 孔祥明, 等. 硅酸盐水泥水化动力学模型与试验方法研究进展[J]. 硅酸盐学报, 2022, 50(6): 1728-1761.
ZHAO K Y, ZHANG P, KONG X M, et al. Recent progress on Portland cement hydration kinetic models and experimental methods[J]. Journal of the Chinese Ceramic Society, 2022, 50(6): 1728-1761 (in Chinese).
[27] 褚会超, 吕宪俊, 张燕, 等. 降低泡沫混凝土吸水率的研究现状及展望[J]. 硅酸盐通报, 2016, 35(9): 2852-2859.
CHU H C, LYU X J, ZHANG Y, et al. Status and prospects of research on reducing the water absorption of foamed concrete[J]. Bulletin of the Chinese Ceramic Society, 2016, 35(9): 2852-2859 (in Chinese).
[28] 牛云辉, 蒋俊, 张玉苹, 等. 自流平泡沫混凝土流动性能影响研究[J]. 混凝土与水泥制品, 2016(11): 65-68.
NIU Y H, JIANG J, ZHANG Y P, et al. Influence research on fluidity of self-leveling foam concrete[J]. China Concrete and Cement Products, 2016(11): 65-68 (in Chinese).