偏高岭土-粉煤灰基地聚物砂浆力学性能研究

摘要/Abstract

摘要： 本研究以偏高岭土和粉煤灰为原料,以不同模数(0.75、1.00、1.25、1.50)和碱浓度(质量分数)(40%、44%、48%)的钾水玻璃为碱激发剂,微珠、蛭石和珍珠岩为细骨料来制备地聚物砂浆试件。主要通过测试地聚物砂浆试件常温及1 000 ℃高温作用后的抗压强度,探明碱激发剂模数和浓度对砂浆试件力学性能的影响,并利用XRD、SEM手段对地聚物的物相组成及微观形貌进行表征。结果表明:当碱浓度不变时,除40%碱浓度外,其余试件的抗压强度随模数的增大先升高后略微降低或者基本不变。当模数不变时,除模数为0.75的试件外,其余试件的抗压强度随碱浓度的增大先升高后降低。当模数为1.00且碱浓度为44%时,试件的抗压强度最高,历经1 000 ℃高温后地聚物砂浆试件相对残余强度仍能维持42%及以上,该温度下水化产物为白榴石(KAlSi₂O₆)和钾霞石(KAlSiO₄),地聚物在常温下有大量絮状的水化产物生成且微观结构较为致密。

关键词: 偏高岭土-粉煤灰基地聚物, 砂浆, 抗压强度, 碱浓度, 模数, 高温, 微观结构

Abstract: In this study, geopolymer mortar specimens were prepared with metakaolin and fly ash as raw materials, potassium sodium silicate with different modulus (0.75, 1.00, 1.25, 1.50) and alkali concentration (mass fraction) (40%, 44%, 48%) as alkali activator, and microbeads, vermiculite and perlite as fine aggregate. The compressive strength of geopolymer mortar specimens at room temperature and 1 000 ℃ high temperature were tested, the influences of the modulus and concentration of alkali activator on the mechanical properties of mortar specimens were explored, and the phase composition and micro-morphology of geopolymer were characterized by XRD and SEM. The test results show that when the alkali concentration is unchanged (except concentration of 40%), the compressive strength of most specimens increase first and then decrease slightly or remain basically unchanged with the increase of modulus. When the modulus remains unchanged (except modulus of 0.75), the compressive strength of most specimens increase first and then decrease with the increase of alkali concentration. When the modulus is 1.00 and the alkali concentration is 44%, the compressive strength of the specimen is the highest. After 1 000 ℃ high temperature, the relative residual strength of the sample still maintains at 42% or above. The hydration products after 1 000 ℃ are leucite (KAlSi₂O₆) and potassiumnephritic (KAlSiO₄). And a large number of flocculent hydration products are formed at room temperature and the microstructure is relatively compact.

Key words: geopolymer based on metakaolin and fly ash, mortar, compressive strength, alkali concentration, modulus, high temperature, microstructure

中图分类号:

TU526

管柏伦, 郭荣鑫, 齐荣庆, 付朝书, 张敏, 张文帅. 偏高岭土-粉煤灰基地聚物砂浆力学性能研究[J]. 硅酸盐通报, 2021, 40(4): 1250-1257.

GUAN Bolun, GUO Rongxin, QI Rongqing, FU Chaoshu, ZHANG Min, ZHANG Wenshuai. Mechanical Properties of Geopolymer Mortar Based on Metakaolin and Fly Ash[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(4): 1250-1257.

参考文献

[1] 徐彧,徐志胜.高温作用后混凝土强度试验研究[J].混凝土,2000(2):44-45+53.
XU Y, XU Z S. Experiment investigation of strength of concrete after high temperature[J]. Concrete, 2000(2): 44-45+53 (in Chinese).
[2] VAN DEVENTER J S J, PROVIS J L, DUXSON P. Technical and commercial progress in the adoption of geopolymer cement[J]. Minerals Engineering, 2012, 29: 89-104.
[3] ZHANG Y S, SUN W, CHEN Q L, et al. Synthesis and heavy metal immobilization behaviors of slag based geopolymer[J]. Journal of Hazardous Materials, 2007, 143(1/2): 206-213.
[4] DUAN P, YAN C J, ZHOU W, et al. An investigation of the microstructure and durability of a fluidized bed fly ash-metakaolin geopolymer after heat and acid exposure[J]. Materials & Design, 2015, 74: 125-137.
[5] 郑娟荣,张涛,覃维祖.碱-偏高岭土基胶凝材料的热稳定性研究[J].郑州大学学报(工学版),2004,25(4):16-19.
ZHENG J R, ZHANG T, QIN W Z. High-temperature stability of cementitious materials based on metakaolin[J]. Journal of Zhengzhou University (Engineering Science), 2004, 25(4): 16-19 (in Chinese).
[6] 侯云芬,王栋民,李俏.激发剂对粉煤灰基地聚合物抗压强度的影响[J].建筑材料学报,2007,10(2):214-218.
HOU Y F, WANG D M, LI Q. Effects of activator on compressive strength of fly ash-based geopolymers[J]. Journal of Building Materials, 2007, 10(2): 214-218 (in Chinese).
[7] ALONSO S, PALOMO A. Calorimetric study of alkaline activation of calcium hydroxide-metakaolin solid mixtures[J]. Cement and Concrete Research, 2001, 31(1): 25-30.
[8] 陈士堃.偏高岭土基地聚合物基础力学性能与影响因素研究[D].杭州:浙江大学,2015.
CHEN S K. Study of basic mechanical properties and influential factors of metakaolin-based geopolymer[D]. Hangzhou: Zhejiang University, 2015 (in Chinese).
[9] LYU S J, WANG T T, CHENG T W, et al. Main factors affecting mechanical characteristics of geopolymer revealed by experimental design and associated statistical analysis[J]. Construction and Building Materials, 2013, 43: 589-597.
[10] 郑娟荣,刘丽娜.偏高岭土基地质聚合物合成条件的试验研究[J].郑州大学学报(工学版),2008,29(2):44-47.
ZHENG J R, LIU L N. Experimental study on formation conditions of metakaolinite-based geopolymer[J]. Journal of Zhengzhou University (Engineering Science), 2008, 29(2): 44-47 (in Chinese).
[11] 李启华,丁天庭,陈树东.粉煤灰-矿渣碱激发体系的早期性能和耐高温研究[J].硅酸盐通报,2017,36(1):365-368+373.
LI Q H, DING T T, CHEN S D. Early property and high temperature resistance of alkali activated system of fly ash-slag[J]. Bulletin of the Chinese Ceramic Society, 2017, 36(1): 365-368+373 (in Chinese).
[12] 姚韦靖,庞建勇.玻化微珠保温混凝土高温后性能劣化及微观结构[J].复合材料学报,2019,36(12):2932-2941.
YAO W J, PANG J Y. Performance degradation and microscopic structure of glazed hollow bead insulation normal concrete after exposure to high temperature[J]. Acta Materiae Compositae Sinica, 2019, 36(12): 2932-2941 (in Chinese).
[13] 吴仕成,严捍东.膨胀玻化微珠及其在水泥基材料中应用现状的综述和分析[J].材料导报,2012,26(23):18-23.
WU S C, YAN H D. Review and analysis of surface-vitrified micron sphere and its application status in cement-based materials[J]. Materials Review, 2012, 26(23): 18-23 (in Chinese).
[14] 程小伟.隧道防火涂料的制备及表征[D].成都:四川大学,2005.
CHENG X W. Preparation and characterization of fireproof coating for tunnels[D]. Chengdu: Sichuan University, 2005 (in Chinese).
[15] 夏海江,鲁雪艳,迪里夏提·买买提.膨胀蛭石:综合性能超凡的高温隔热材料[J].西部探矿工程,2008,20(2):111-112.
XIA H J, LU X Y, DILIXIATI M M T. Expanded vermiculite: a high temperature insulation material with extraordinary comprehensive performance[J]. West-China Exploration Engineering, 2008, 20(2): 111-112 (in Chinese).
[16] 杨立荣,王春梅,封孝信,等.粉煤灰/矿渣基地聚合物的制备及固化机理研究[J].武汉理工大学学报,2009,31(7):115-119.
YANG L R, WANG C M, FENG X X, et al. Preparation and consolidation mechanism of fly ash-based geopolymer incorporating slag[J]. Journal of Wuhan University of Technology, 2009, 31(7): 115-119 (in Chinese).
[17] 李亚林.粉煤灰-偏高岭土复合基地质聚合物的结构与性能研究[D].绵阳:西南科技大学,2017.
LI Y L. Study on the structure and properties of fly ash-metakaolin composite based geopolymer[D]. Mianyang: Southwest University of Science and Technology, 2017 (in Chinese).
[18] 章定文,王安辉.地聚合物胶凝材料性能及工程应用研究综述[J].建筑科学与工程学报,2020,37(5):13-38.
ZHANG D W, WANG A H. Review on property of geopolymer binder and its engineering application[J]. Journal of Architecture and Civil Engineering, 2020, 37(5): 13-38 (in Chinese).
[19] 张敏,马倩敏,史天尧,等.磷渣胶凝材料高温力学性能试验研究[J].非金属矿,2018,41(6):10-14.
ZHANG M, MA Q M, SHI T Y, et al. Mechanical properties of mortars containing phosphorus slag after exposure to high temperatures[J]. Non-Metallic Mines, 2018, 41(6): 10-14 (in Chinese).
[20] KONG D L Y, SANJAYAN J G, SAGOE-CRENTSIL K. Factors affecting the performance of metakaolin geopolymers exposed to elevated temperatures[J]. Journal of Materials Science, 2008, 43(3): 824-831.
[21] LIZCANO M, KIM H S, BASU S, et al. Mechanical properties of sodium and potassium activated metakaolin-based geopolymers[J]. Journal of Materials Science, 2012, 47(6): 2607-2616.
[22] 李娜,徐中慧,李萍,等.机械力活化粉煤灰制备地聚合物的性能及机理研究[J].功能材料,2018,49(4):4102-4106.
LI N, XU Z H, LI P, et al. Mechanical activation of fly ash: effect on performance and mechanism of resulting geopolymer[J]. Journal of Functional Materials, 2018, 49(4): 4102-4106 (in Chinese).
[23] SELMANI S, SDIRI A, BOUAZIZ S, et al. Effects of metakaolin addition on geopolymer prepared from natural kaolinitic clay[J]. Applied Clay Science, 2017, 146: 457-467.
[24] 李娜,徐中慧,陈筱悦,等.偏高岭土基地聚合物高温陶瓷化特性研究[J].硅酸盐通报,2019,38(4):957-961.
LI N, XU Z H, CHEN X Y, et al. Characteristics of metakaolinite-based geopolmers after exposure to high temperatures[J]. Bulletin of the Chinese Ceramic Society, 2019, 38(4): 957-961 (in Chinese).
[25] 黄丽婷,刘洋,彭诚,等.立方相白榴石的合成与稳定[J].硅酸盐学报,2017,45(7):948-954.
HUANG L T, LIU Y, PENG C, et al. Synthesis and stabilization of cubic leucite[J]. Journal of the Chinese Ceramic Society, 2017, 45(7): 948-954 (in Chinese).
[26] KONG D L Y, SANJAYAN J G, SAGOE-CRENTSIL K. Comparative performance of geopolymers made with metakaolin and fly ash after exposure to elevated temperatures[J]. Cement and Concrete Research, 2007, 37(12): 1583-1589.
[27] VILLAQUIRÁN-CAICEDO M A. Studying different silica sources for preparation of alternative waterglass used in preparation of binary geopolymer binders from metakaolin/boiler slag[J]. Construction and Building Materials, 2019, 227: 116621.
[28] 黄丽婷.低热膨胀系数立方相白榴石的合成与稳定[D].广州:华南理工大学,2017.
HUANG L T. Synthesis and stabilization of cubic leucite with low coefficient of thermal expansion[D]. Guangzhou: South China University of Technology, 2017 (in Chinese).