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

摘要/Abstract

摘要： 针对胶凝材料比表面积和粒度分布等物理性质存在的差异,将P·Ⅱ水泥,Ⅰ级、Ⅱ级粉煤灰和S95级、S105级矿渣进行互掺,固定水泥用量,设计了4种粉煤灰和矿渣的组合方式,通过流动度试验分析了组合方式对净浆流动性的影响,并将粒度分布曲线与Fuller分布曲线进行了比较。在净浆配合比的基础上,对不同组合方式的混凝土进行了工作性、力学性能及自由氯离子浓度测试,探讨了粉煤灰和矿渣的粒度分布对混凝土强度和抗氯离子渗透性的影响,并对硬化浆体水化产物的微观形貌和化学组成进行了分析,揭示了影响机理。研究结果表明,矿物掺合料的粒度分布是决定颗粒级配优劣的重要因素。Ⅰ级粉煤灰具有更强的滚珠效应,在提高流动性方面起了关键性作用。粉煤灰和矿渣的水化及火山灰反应程度影响着混凝土的力学性能和耐久性能,由于Ⅰ级粉煤灰有更大的比表面积,火山灰活性也较高,因此Ⅰ级粉煤灰和S95/S105级矿渣组合的净浆流动度,混凝土的工作性、抗压强度和抗氯离子渗透性均明显高于Ⅱ级粉煤灰和S95/S105级矿渣组合。其中Ⅰ级粉煤灰和S95级矿渣组合的胶凝材料粒度分布曲线与Fuller曲线最为接近,粒度分布最优,水化浆体中Ca(OH)₂含量最低,火山灰反应最为充分,对应的混凝土微观结构致密,抗氯离子渗透性最好。

关键词: 混凝土, 粉煤灰, 矿渣, 粒度分布, 微观结构, 氯离子渗透

Abstract: This study is aimed at the differences of physical properties such as specific surface area and particle size distribution of cementitious materials. The P·Ⅱ cement, grade Ⅰ and grade Ⅱ fly ash, grade S95 and grade S105 slag were intermixed. Four combinations of fly ash and slag were designed on the premise of fixed cement dosage. The effect of the combination method on the fluidity of the pure slurry was analyzed through the fluidity experiment, and the particle size curve was compared with the Fuller distribution curve. Tests on workability, mechanical properties and free chloride ion concentration of concrete with different combinations were carried out on the basis of the pure slurry mix proportion. The microscopic morphology and chemical composition of hydration product of hardened slurry were analyzed. The effects of particle size distribution of fly ash and slag on the strength and chloride ion penetration resistance of concrete were discussed, and the influence mechanism was revealed. The research results show that the particle size distribution of mineral admixtures is an important factor in determining the quality of particle gradation. The ball effect of grade Ⅰ fly ash is stronger, which makes it play a key role in improving fluidity. The mechanical properties and durability of concrete are affected by the hydration of fly ash and slag, and the degree of pozzolanic reaction. The grade Ⅰ fly ash has larger specific surface area and higher pozzolanic activity. Therefore, the fluidity, workability, compressive strength and chloride ion penetration resistance of grade Ⅰ fly ash and S95/S105 slag combination group are significantly higher than the combination of grade Ⅱ fly ash and S95/S105 slag combination group. Among all the combinations in this experiment, the particle size distribution curve of cementitious material of the combination of grade Ⅰ fly ash and grade S95 slag is the closest to the Fuller curve. The particle size distribution of this combination is the best, the content of Ca(OH)₂ in the hydrated slurry is the lowest, and the pozzolanic reaction is the most sufficient. The corresponding concrete has a dense internal structure, and the chloride ion penetration resistance of concrete is good.

Key words: concrete, fly ash, slag, particle size distribution, microstructure, chloride ion penetration

中图分类号:

TU528

安强, 潘慧敏, 王帅, 赵庆新. 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 Qiang, PAN Huimin, WANG Shuai, ZHAO Qingxin. 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.

参考文献

[1] 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).
[2] 韩建国,毕耀,黎梦圆,等.矿物掺合料和化学外加剂对胶凝材料浆体的流变参数的影响[J].土木工程学报,2021,54(10):55-63.
HAN J G, BI Y, LI M Y, et al. Effect of mineral and chemical admixtures on rheological parameters of binder paste[J]. China Civil Engineering Journal, 2021, 54(10): 55-63 (in Chinese).
[3] BEHERA S K, MISHRA D P, SINGH P, et al. Utilization of mill tailings, fly ash and slag as mine paste backfill material: review and future perspective[J]. Construction and Building Materials, 2021, 309: 125120.
[4] 刘仍光,阎培渝.水泥-矿渣复合胶凝材料中矿渣的水化特性[J].硅酸盐学报,2012,40(8):1112-1118.
LIU R G, YAN P Y. Hydration characteristics of slag in cement-slag complex binder[J]. Journal of the Chinese Ceramic Society, 2012, 40(8): 1112-1118 (in Chinese).
[5] WANG X Y. Analysis of hydration kinetics and strength progress in cement-slag binary composites[J]. Journal of Building Engineering, 2021, 35: 101810.
[6] 徐泽华,赵庆新,张津瑞,等.界面过渡区对混凝土徐变性能的影响[J].硅酸盐学报,2021,49(2):347-356.
XU Z H, ZHAO Q X, ZHANG J R, et al. Influence of interface transition zone on creep properties of concrete[J]. Journal of the Chinese Ceramic Society, 2021, 49(2): 347-356 (in Chinese).
[7] FULLER W B, THOMPSON S E. The laws of proportioning concrete[J]. Transactions of the American Society of Civil Engineers, 1907, 59(2): 67-143.
[8] 李滢,杨静.胶凝材料颗粒级配对水泥凝胶体结构及强度的影响[J].新型建筑材料,2004,31(3):1-4.
LI Y, YANG J. Effect of particle size of cementitious material on structure and strength of cement gel[J]. New Building Materials, 2004, 31(3): 1-4 (in Chinese).
[9] SEVIM O, BARAN M, DEMIR Š. Mechanical and physical properties of cementitious composites containing fly ash or slag classified with help of particle size distribution[J]. Romanian Journal of Materials, 2021, 51(1): 67-77.
[10] 赵旭光,文梓芸,赵三银,等.高炉矿渣粉的粒度分布对其性能的影响[J].硅酸盐学报,2005,33(7):907-911+915.
ZHAO X G, WEN Z Y, ZHAO S Y, et al. Effect of particle size distribution of ground granulated blast furnace slag on its properties[J]. Journal of the Chinese Ceramic Society, 2005, 33(7): 907-911+915 (in Chinese).
[11] CAO C, CHEUNG M M S. Non-uniform rust expansion for chloride-induced pitting corrosion in RC structures[J]. Construction and Building Materials, 2014, 51: 75-81.
[12] 姜文镪,刘清风.冻融循环下混凝土中氯离子传输研究进展[J].硅酸盐学报,2020,48(2):258-272.
JIANG W Q, LIU Q F. Chloride transport in concrete subjected to freeze-thaw cycles: a short review[J]. Journal of the Chinese Ceramic Society, 2020, 48(2): 258-272 (in Chinese).
[13] ZHAO H, SUN W, WU X M, et al. The properties of the self-compacting concrete with fly ash and ground granulated blast furnace slag mineral admixtures[J]. Journal of Cleaner Production, 2015, 95: 66-74.
[14] FAN J C, ZHU H G, SHI J, et al. Influence of slag content on the bond strength, chloride penetration resistance, and interface phase evolution of concrete repaired with alkali activated slag/fly ash[J]. Construction and Building Materials, 2020, 263: 120639.
[15] ZARZUELA R, LUNA M, CARRASCOSA L M, et al. Producing C-S-H gel by reaction between silica oligomers and portlandite: a promising approach to repair cementitious materials[J]. Cement and Concrete Research, 2020, 130: 106008.
[16] 韩方晖,刘仍光,阎培渝.矿渣对复合胶凝材料硬化浆体微观结构的影响[J].电子显微学报,2014,33(1):40-45.
HAN F H, LIU R G, YAN P Y. Influence of slag on microstructure of complex binder pastes[J]. Journal of Chinese Electron Microscopy Society, 2014, 33(1): 40-45 (in Chinese).
[17] LI W T, YI Y L. Use of carbide slag from acetylene industry for activation of ground granulated blast-furnace slag[J]. Construction and Building Materials, 2020, 238: 117713.
[18] PHOO-NGERNKHAM T, PHIANGPHIMAI C, INTARABUT D, et al. Low cost and sustainable repair material made from alkali-activated high-calcium fly ash with calcium carbide residue[J]. Construction and Building Materials, 2020, 247: 118543.
[19] YI Y, LI C, LIU S, et al. Magnesium sulfate attack on clays stabilised by carbide slag- and magnesia-ground granulated blast furnace slag[J]. Géotechnique Letters, 2015, 5(4): 306-312.
[20] 杜惠惠,倪文,高广军.水淬高钛高炉渣制备C40全固废混凝土试验研究[J].材料导报,2020,34(24):24055-24060.
DU H H, NI W, GAO G J. Experimental study on preparation of C40 concrete with industrial solid wastes from high-titanium blast furnace slag[J]. Materials Reports, 2020, 34(24): 24055-24060 (in Chinese).
[21] DE AZEVEDO N H, DE MATOS P R, GLEIZE P J P, et al. Effect of thermal treatment of SiC nanowhiskers on rheological, hydration, mechanical and microstructure properties of Portland cement pastes[J]. Cement and Concrete Composites, 2021, 117: 103903.
[22] CHEN X, LI J S, XUE Q, et al. Sludge biochar as a green additive in cement-based composites: mechanical properties and hydration kinetics[J]. Construction and Building Materials, 2020, 262: 120723.
[23] CHENG X J, SHI L, LIU Q Y, et al. Heat effects of pyrolysis of 15 acid washed coals in a DSC/TGA-MS system[J]. Fuel, 2020, 268: 117325.
[24] 胡建城,吕阳,何晨昊,等.纳米二氧化硅粉末对水泥-粉煤灰体系泡沫混凝土力学性能及水化的影响[J].硅酸盐通报,2019,38(5):1390-1394.
HU J C, LYU Y, HE C H, et al. Effect of nano-silica on mechanical properties and hydration of foamed concrete in the cement-fly ash system[J]. Bulletin of the Chinese Ceramic Society, 2019, 38(5): 1390-1394 (in Chinese).
[25] GWON S, CHOI Y C, SHIN M. Effect of plant cellulose microfibers on hydration of cement composites[J]. Construction and Building Materials, 2021, 267: 121734.