Interface Characteristics and Regulation of Core-Shell Structure Phosphogypsum-Based Aggregate/Portland Cement

doi:10.16552/j.cnki.issn1001-1625.2024.0977

Abstract

Abstract: In order to solve the compatibility problem between phosphogypsum-based aggregate and ordinary Portland cement, a core-shell structure phosphogypsum-based aggregate was prepared in this paper. Based on the systematic study of the influence of the composition of aggregate shell on the macroscopic properties such as aggregate water absorption, cylinder compressive strength and compressive strength, the influence of the composition of aggregate shell on the microstructure characteristics of the interfacial transition zone of concrete was studied by means of modern analysis and testing methods. The results show that the performance of the core-shell structure phosphogypsum-based aggregate is improved compared with the uncoated aggregate, and the compressive strength of the concrete test block made of this aggregate and ordinary Portland cement is improved. The interface formed by phosphogypsum-based aggregate and cement with core-shell structure is compared with that without shell. In the early stage of hydration, the content of Ca(OH)₂ at the interface is reduced, the pore structure at the interface is optimized, the microhardness at the interface is improved, the width of the interfacial transition zone is reduced, and the shell layer can reduce the probability of S element in the aggregate core diffusing to the interface. In the later stage of hydration, the hydration reaction at the interface is basically stable, and the shell layer can still slow down the trend of S element diffusion from the core to the interface, reduce the risk of expansion and cracking at the interface, and increase the feasibility of the application of phosphogypsum-based aggregate in ordinary Portland cement system.

Key words: phosphogypsum-based aggregate, core-shell structure, interfacial transition zone, reaction mechanism, porosity

CLC Number:

TU526

HE Jing, LYU Wei, WU Chiqiu, YU Zhengkang, LI Yisheng, SHUI Zhonghe. Interface Characteristics and Regulation of Core-Shell Structure Phosphogypsum-Based Aggregate/Portland Cement[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2025, 44(2): 613-622.

References

[1] YANG M, QIAN J S, PANG Y. Activation of fly ash-lime systems using calcined phosphogypsum[J]. Construction and Building Materials, 2008, 22(5): 1004-1008.
[2] RASHAD A M. Potential use of phosphogypsum in alkali-activated fly ash under the effects of elevated temperatures and thermal shock cycles[J]. Journal of Cleaner Production, 2015, 87: 717-725.
[3] 周武, 李杨, 冯伟光, 等. 磷石膏的综合利用及其在建筑材料领域的应用研究进展[J]. 硅酸盐通报, 2024, 43(2): 534-542.
ZHOU W, LI Y, FENG W G, et al. Research progress on comprehensive utilization of phosphogypsum and its application in the field of building materials[J]. Bulletin of the Chinese Ceramic Society, 2024, 43(2): 534-542 (in Chinese).
[4] 马丽萍. 磷石膏资源化综合利用现状及思考[J]. 磷肥与复肥, 2019, 34(7): 5-9.
MA L P. Current situation and consideration of comprehensive utilization of phosphogypsum resources[J]. Phosphate & Compound Fertilizer, 2019, 34(7): 5-9 (in Chinese).
[5] 俞坚, 郭程铭, 毛裕均. 改性磷石膏用作水泥缓凝剂的试验研究[J]. 新型建筑材料, 2015, 42(9): 31-33.
YU J, GUO C M, MAO Y J. Experimental study on the using of modified phosphogypsum as cement retarder[J]. New Building Materials, 2015, 42(9): 31-33 (in Chinese).
[6] 水中和, 吴赤球, 孙涛, 等. 过硫磷石膏矿渣水泥混凝土的研究与应用进展[J]. 混凝土与水泥制品, 2021(2): 97-100.
SHUI Z H, WU C Q, SUN T, et al. Research and application progress of excess-sulfate phosphogypsum slag cement concrete[J]. China Concrete and Cement Products, 2021(2): 97-100 (in Chinese).
[7] 刘超, 赵德强, 马倩, 等. 水泥-磷石膏稳定碎石路面基层材料的研究与应用[J]. 硅酸盐通报, 2023, 42(6): 2121-2130.
LIU C, ZHAO D Q, MA Q, et al. Research and application of cement-phosphogypsum stabilized crushed stone pavement base material[J]. Bulletin of the Chinese Ceramic Society, 2023, 42(6): 2121-2130 (in Chinese).
[8] 宗炜, 王远辉, 许亮, 等. 工业固废磷石膏路面基层材料路用性能研究[J]. 硅酸盐通报, 2024, 43(2): 766-773.
ZONG W, WANG Y H, XU L, et al. Pavement performance of industrial solid waste phosphogypsum pavement base material[J]. Bulletin of the Chinese Ceramic Society, 2024, 43(2): 766-773 (in Chinese).
[9] SENGUPTA I, DHAL P K. Impact of elevated phosphogypsum on soil fertility and its aerobic biotransformation through indigenous microorganisms (IMO’s) based technology[J]. Journal of Environmental Management, 2021, 297: 113195.
[10] 吴赤球, 水中和, 吕伟, 等. 超高掺量磷石膏水硬性胶凝材料及其应用[M]. 武汉: 武汉理工大学出版社, 2023.
WU C Q, SHUI Z H, LYU W, et al. High dosage phosphogypsum hydraulic cementing material and its application[M]. Wuhan: Wuhan University of Technology Press, 2023 (in Chinese).
[11] OUYANG G S, SUN T, YU Z C, et al. Investigation on macroscopic properties, leachability and microstructures of surface reinforced phosphogypsum-based cold-bonded aggregates[J]. Journal of Building Engineering, 2023, 69: 106305.
[12] SUN T, LI W M, XU F, et al. A new eco-friendly concrete made of high content phosphogypsum based aggregates and binder: mechanical properties and environmental benefits[J]. Journal of Cleaner Production, 2023, 400: 136555.
[13] LIU X, WU C Q, LV W, et al. Regulating sulfur migration and transformation in low water-binder ratio cementitious system incorporating phosphogypsum aggregate: environmentally friendly clean materials[J]. Journal of Building Engineering, 2024, 91: 109586.
[14] DONG E L, FU S Y, WU C Q, et al. Value-added utilization of phosphogypsum industrial by-products in producing green ultra-high performance concrete: detailed reaction kinetics and microstructure evolution mechanism[J]. Construction and Building Materials, 2023, 389: 131726.
[15] 马昆林, 刘建, 申景涛, 等. 骨料强化方法对再生混凝土多界面过渡区微观结构的影响[J]. 铁道科学与工程学报, 2023, 20(10): 3809-3819.
MA K L, LIU J, SHEN J T, et al. Influence of aggregate enhancement methods on the microstructure of multiple ITZs in recycled concrete[J]. Journal of Railway Science and Engineering, 2023, 20(10): 3809-3819 (in Chinese).
[16] 高嵩, 班顺莉, 郭嘉, 等. 硅灰对再生混凝土界面过渡区的影响[J]. 材料导报, 2023, 37(11): 97-103.
GAO S, BAN S L, GUO J, et al. Effect of silica fume on interfacial transition zone of recycled concrete[J]. Materials Reports, 2023, 37(11): 97-103 (in Chinese).
[17] SUN D D, SHI H S, WU K, et al. Influence of aggregate surface treatment on corrosion resistance of cement composite under chloride attack[J]. Construction and Building Materials, 2020, 248: 118636.
[18] 肖智慧, 李中军, 吕伟, 等. 磷石膏路基稳定材料的节能减排效益分析[J]. 混凝土与水泥制品, 2023(7): 99-102.
XIAO Z H, LI Z J, LYU W, et al. Benefits analysis of energy saving and emission reduction of phosphogypsum roadbed stabilizing material[J]. China Concrete and Cement Products, 2023(7): 99-102 (in Chinese).
[19] 杨秀丽, 崔崇, 崔晓昱, 等. 壳层增强人造硅酸盐骨料性能[J]. 科技导报, 2014, 32(25): 26-31.
YANG X L, CUI C, CUI X Y, et al. Properties of shell reinforced artificial silicate aggregate[J]. Science & Technology Review, 2014, 32(25): 26-31 (in Chinese).
[20] 丁超. 磷石膏基冷粘结集料的制备及性能优化研究[D]. 武汉: 武汉理工大学, 2022.
DING C. Study on preparation and performance optimization of phosphogypsum-based cold bonded aggregate[D]. Wuhan: Wuhan University of Technology, 2022 (in Chinese).
[21] 黎良元, 石宗利, 艾永平. 石膏-矿渣胶凝材料的碱性激发作用[J]. 硅酸盐学报, 2008, 36(3): 405-410.
LI L Y, SHI Z L, AI Y P. Alkaline activation of gypsum-granulated blast furnace slag cementing materials[J]. Journal of the Chinese Ceramic Society, 2008, 36(3): 405-410 (in Chinese).
[22] LIU H, SUN Z P, YANG J B, et al. A novel method for semi-quantitative analysis of hydration degree of cement by ¹H low-field NMR[J]. Cement and Concrete Research, 2021, 141: 106329.
[23] TIAN Y, TIAN Z S, JIN N G, et al. A multiphase numerical simulation of chloride ions diffusion in concrete using electron microprobe analysis for characterizing properties of ITZ[J]. Construction and Building Materials, 2018, 178: 432-444.
[24] 黄赟. 磷石膏基水泥的开发研究[D]. 武汉: 武汉理工大学, 2010.
HUANG Y. Development and research of phosphogypsum-based cement[D]. Wuhan: Wuhan University of Technology, 2010 (in Chinese).
[25] DIAMOND S. Considerations in image analysis as applied to investigations of the ITZ in concrete[J]. Cement and Concrete Composites, 2001, 23(2/3): 171-178.
[26] FANG G H, ZHANG M Z. The evolution of interfacial transition zone in alkali-activated fly ash-slag concrete[J]. Cement and Concrete Research, 2020, 129: 105963.
[27] WONG H S, HEAD M K, BUENFELD N R. Pore segmentation of cement-based materials from backscattered electron images[J]. Cement and Concrete Research, 2006, 36(6): 1083-1090.
[28] 黄燕, 胡翔, 史才军, 等. 混凝土中水泥浆体与骨料界面过渡区的形成和改进综述[J]. 材料导报, 2023, 37(1): 106-117.
HUANG Y, HU X, SHI C J, et al. Review on the formation and improvement of interfacial transition zone between cement paste and aggregate in concrete[J]. Materials Reports, 2023, 37(1): 106-117 (in Chinese).
[29] 陈培鑫. BEI-GSR分析技术在复合水泥浆体结构中的应用研究[D]. 广州: 华南理工大学, 2013.
CHEN P X. Study on application of BEI-GSR analysis technology in composite cement paste structure[D]. Guangzhou: South China University of Technology, 2013 (in Chinese).
[30] 王培铭, 丰曙霞, 刘贤萍. 背散射电子图像分析在水泥基材料微观结构研究中的应用[J]. 硅酸盐学报, 2011, 39(10): 1659-1665.
WANG P M, FENG S X, LIU X P. Application of backscattered electron imaging and image analysis in microstructure research on cement-based materials[J]. Journal of the Chinese Ceramic Society, 2011, 39(10): 1659-1665 (in Chinese).
[31] MA Z M, YAO P P, YANG D Y, et al. Effects of fire-damaged concrete waste on the properties of its preparing recycled aggregate, recycled powder and newmade concrete[J]. Journal of Materials Research and Technology, 2021, 15: 1030-1045.
[32] 丁沙. 过硫磷石膏矿渣水泥混凝土抗海盐侵蚀性能与机理研究[D]. 武汉: 武汉理工大学, 2014.
DING S. Study on the anti-sea salt corrosion performance and mechanism of supersulphated cement concrete with parathion[D]. Wuhan: Wuhan University of Technology, 2014 (in Chinese).