高掺量磷石膏水硬性胶凝材料组成设计与性能调节

摘要/Abstract

摘要： 本文研究的水硬性磷石膏胶凝材料体系由80%(质量分数)磷石膏,以及少量矿渣、水泥、偏高岭土、粉煤灰、硅灰等辅助胶凝材料组成,借助力学性能试验数据与分子动力学(MD)模拟为超高掺量磷石膏体系组成设计提供依据,后续对该体系强度倒缩问题进行性能调节。结果表明,当磷石膏掺量固定时,辅助胶凝材料(SCM)的n(CaO)/n(SiO₂+Al₂O₃)摩尔比接近1的样品力学性能结果最佳。分子动力学对模型原子表面积和孔结构分布的模拟结果与力学性能规律相符,孔结构越小时抗压强度越高;在原子尺度上,n(CaO)/n(SiO₂+Al₂O₃)摩尔比接近1时O、Ca、Al及S原子表现出较高的扩散能力,可充分发挥碱激发与硫酸盐激发效应,同时使得OO、Al—O、Si—O键长增大而失稳水解,促进水化产物钙钒石的生成。最后,通过调节SCM的种类,在磷石膏-矿渣-水泥体系中复掺偏高岭土、硅灰及粉煤灰改善了90 d龄期强度倒缩的问题。基于化学组分设计配合比对大宗量利用磷石膏以及获得性能更好的胶凝材料具有重要意义。

关键词: 高掺量磷石膏, 化学成分, 分子动力学模拟, 组成设计, 性能调节

Abstract: The hydraulic phosphogypsum cementing material system studied in this paper is composed of 80% (mass fraction) phosphogypsum and a small amount of auxiliary cementing materials such as slag, cement, metacaolin, fly ash and silica fume. Mechanical properties test and molecular dynamics (MD) simulation are used to provide a basis for the composition design of high content phosphogypsum system, and then the strength shrinkage of the system is adjusted. The results show that when the content of phosphogypsum is fixed, the n(CaO)/n(SiO₂+Al₂O₃) molar ratio of the supplementary cementitious material (SCM) is close to 1, and the mechanical properties of the sample are the best. The results of molecular dynamics simulation on the atomic surface area and pore structure distribution of the model are consistent with the mechanical properties. The smaller the pore structure, the higher the compressive strength. On the atomic scale, O, Ca, Al and S atoms show high diffusion ability in molecular dynamics simulations with the molar ratio of n(CaO)/n(SiO₂+Al₂O₃) close to 1, which can give full play to alkali and sulfate excitation effects, and at the same time, increase the bond length of OO, Al—O and Si—O, resulting in unstable hydrolysis and promote the formation of calcium vanadite as a hydration product. Finally, by adjusting the types of auxiliary cementing materials, adding metakaolin, wollastonite and fly ash into phosphogypsum-slag-cement system, the problem of strength shrinkage at 90 d age is improved. It is of great significance to design and use phosphogypsum based on chemical composition and obtain better cementing materials.

Key words: high content phosphogypsum, chemical composition, molecular dynamics simulation, composition design, performance regulation

中图分类号:

TU526

刘爱平, 吴赤球, 水中和, 吕伟, 练九阳. 高掺量磷石膏水硬性胶凝材料组成设计与性能调节[J]. 硅酸盐通报, 2024, 43(3): 1003-1011.

LIU Aiping, WU Chiqiu, SHUI Zhonghe, LYU Wei, LIAN Jiuyang. Composition Design and Property Regulation of High Content Phosphogypsum Hydraulic Cementing Material[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(3): 1003-1011.

参考文献

[1] TAHER M A. Influence of thermally treated phosphogypsum on the properties of Portland slag cement[J]. Resources, Conservation and Recycling, 2007, 52(1): 28-38.
[2] POTGIETER J H, POTGIETER S S, MCCRINDLE R I. A comparison of the performance of various synthetic gypsums in plant trials during the manufacturing of OPC clinker[J]. Cement and Concrete Research, 2004, 34(12): 2245-2250.
[3] SINGH M. Role of phosphogypsum impurities on strength and microstructure of selenite plaster[J]. Construction and Building Materials, 2005, 19(6): 480-486.
[4] 林宗寿, 黄赟, 水中和. 过硫磷石膏矿渣水泥与混凝土[M]. 武汉: 武汉理工大学出版社, 2015.
LIN Z S, HUANG Y, SHUI Z H, et al. Excess-sulfate phosphogypsum slag cement and concrete[M]. Wuhan: Wuhan University of Technology Press, 2015 (in Chinese).
[5] LIU Q, YANG C, LYU X J, et al. Evolution of ettringite content and its effects on hydration properties of CaO/fluorgypsum-activated granulated blast furnace slag binders[J]. Advanced Composites and Hybrid Materials, 2021, 4(2): 350-359.
[6] WANG Z Y, SHUI Z H, SUN T, et al. Recycling utilization of phosphogypsum in eco excess-sulphate cement: synergistic effects of metakaolin and slag additives on hydration, strength and microstructure[J]. Journal of Cleaner Production, 2022, 358: 131901.
[7] MESKINI S, SAMDI A, EJJAOUANI H, et al. Valorization of phosphogypsum as a road material: stabilizing effect of fly ash and lime additives on strength and durability[J]. Journal of Cleaner Production, 2021, 323: 129161.
[8] REIJNDERS L. Cleaner phosphogypsum, coal combustion ashes and waste incineration ashes for application in building materials: a review[J]. Building and Environment, 2007, 42(2): 1036-1042.
[9] AYDıN S, BARADAN B. Mechanical and microstructural properties of heat cured alkali-activated slag mortars[J]. Materials & Design, 2012, 35: 374-383.
[10] 徐方, 李恒, 孙涛, 等. 基于分子动力学模拟的过硫磷石膏矿渣水泥组成设计[J]. 复合材料学报, 2022, 39(6): 2821-2828.
XU F, LI H, SUN T, et al. Composition design of excess-sulfate phosphogypsum slag cement based on molecular dynamics simulation[J]. Acta Materiae Compositae Sinica, 2022, 39(6): 2821-2828 (in Chinese).
[11] 王善拔, 季尚行, 刘银江, 等. 碱对硫铝酸盐水泥膨胀性能的影响[J]. 硅酸盐学报, 1986, 14(3): 285-292.
WANG S B, JI S X, LIU Y J, et al. Effect of alkali on expansion of sulfoaluminate cement[J]. Journal of the Chinese Ceramic Society, 1986, 14(3): 285-292 (in Chinese).
[12] 赵士豪, 林喜华, 麻鹏飞, 等. 基于临界钙矾石膨胀破坏的磷石膏基复合胶凝材料的配料计算研究[J]. 无机盐工业, 2020, 52(9): 91-95.
ZHAO S H, LIN X H, MA P F, et al. Study on formulation calculation of phosphogypsum-based composite cementitious materials based on expansion and failure of critical AFt[J]. Inorganic Chemicals Industry, 2020, 52(9): 91-95 (in Chinese).
[13] 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).
[14] ZHANG J J, SUN G W, WANG C H, et al. Activation effects and micro quantitative characterization of high-volume ground granulated blast furnace slag in cement-based composites[J]. Cement and Concrete Composites, 2020, 109: 103556.
[15] 兰明章, 唐润荣, 陈智丰, 等. 二氧化硅含量对硫铝酸盐水泥性能的影响[J]. 新世纪水泥导报, 2002, 8(4): 33-36+8.
LAN M Z, TANG R R, CHEN Z F, et al. Effect of silica dioxide content on properties of sulpho-aluminate cement[J]. Cement Guide for New Epoch, 2002, 8(4): 33-36+8 (in Chinese).
[16] HUANG Y B, QIAN J S, LU L C, et al. Phosphogypsum as a component of calcium sulfoaluminate cement: hazardous elements immobilization, radioactivity and performances[J]. Journal of Cleaner Production, 2020, 248: 119287.
[17] 周宇, 徐方, 顾功辉, 等. 地聚合物早期抗压强度及分子动力学模拟[J]. 建筑材料学报, 2021, 24(1): 93-98+120.
ZHOU Y, XU F, GU G H, et al. Early compressive strength and molecular dynamics simulation of geopolymer[J]. Journal of Building Materials, 2021, 24(1): 93-98+120 (in Chinese).
[18] CHEN B M, QIAO G, HOU D S, et al. Cement-based material modified by in situ polymerization: from experiments to molecular dynamics investigation[J]. Composites Part B: Engineering, 2020, 194: 108036.
[19] HOU D S, YU J, LIU Q F, et al. Nanoscale insight on the epoxy-cement interface in salt solution: a molecular dynamics study[J]. Applied Surface Science, 2020, 509: 145322.
[20] LIANG Y Z. Mechanical and fracture properties of calcium silicate hydrate and calcium hydroxide composite from reactive molecular dynamics simulations[J]. Chemical Physics Letters, 2020, 761: 138117.
[21] LIU L B, ZHANG Y S, TAN K F. Cementitious binder of phosphogypsum and other materials[J]. Advances in Cement Research, 2015, 27(10): 567-570.
[22] 杨光, 赵宇, 朱伶俐, 等. 碱激发偏高岭土基地质聚合物的制备及抗压强度研究[J]. 硅酸盐通报, 2022, 41(3): 894-902.
YANG G, ZHAO Y, ZHU L L, et al. Preparation and compressive strength of geopolymer based on alkali activated metakaolin[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(3): 894-902 (in Chinese).
[23] 张涛, 朱成. 水泥-硅灰/粉煤灰体系强度、收缩性能与微观结构研究[J]. 硅酸盐通报, 2022, 41(3): 903-912.
ZHANG T, ZHU C. Strength, shrinkage performance and microstructure of cement-silica fume/fly ash system[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(3): 903-912 (in Chinese).
[24] 翟健梁, 赖淏, 毛楠, 等. 复掺矿物掺合料对氯氧镁水泥耐水性能的影响[J]. 硅酸盐通报, 2022, 41(10): 3590-3598.
ZHAI J L, LAI H, MAO N, et al. Effect of compound mineral admixture on water resistance of magnesium oxychloride cement[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(10): 3590-3598 (in Chinese).
[25] 安强, 潘慧敏, 王帅, 等. 粉煤灰和矿渣粒度分布对混凝土微观结构和抗氯离子渗透性的影响[J]. 硅酸盐通报, 2022, 41(3): 884-893.
AN Q, PAN H M, WANG S, et al. Effects of fly ash and slag particle size distributions on microstructure and chloride ion penetration resistance of concrete[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(3): 884-893 (in Chinese).