Damage and Deterioration Law of Activated Coal Gangue Powder Concrete under Freeze-Thaw

Abstract

Abstract: In order to promote the application of coal gangue in concrete in cold regions, the coal gangue was compound activation by mechanical-microwave method. The damage and deterioration law of coal gangue powder concrete was studied from the aspects of apparent morphology, mass loss rate, relative dynamic elastic modulus, compressive strength and splitting tensile strength. The modification mechanism of activated coal gangue powder on the frost resistance of concrete was studied by scanning electron microscope, nuclear magnetic resonance spectrometer and X-ray diffractometer. The results show that activated coal gangue powder has the best effect on improving the frost resistance of concrete when it replaces cement with 20% (mass fraction). After 300 times freeze-thaw cycles, the mass loss rate and relative dynamic elastic modulus are 2.32% and 91.32%, and the compressive strength and splitting tensile strength decrease by 16.40% and 26.12%, respectively. Activated coal gangue powder can fill and refine pores, and its secondary hydration can consume cement hydration product Ca(OH)₂, and produce C-S-H and C-A-S-H, which can improve the compactness of cement paste, improve the pore structure and reduce the proportion of macropores.

Key words: concrete, coal gangue powder, compressive strength, frost resistance, deterioration law, damage mechanism

CLC Number:

TU528.01

GUAN Xiao, LONG Hang, DING Sha, ZHANG Pengxin. Damage and Deterioration Law of Activated Coal Gangue Powder Concrete under Freeze-Thaw[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2023, 42(1): 144-150.

References

[1] 李坦夫,王姣,周春财,等.淮南矿区主采煤层中矸石的资源利用研究[J].中国煤炭地质,2015,27(8):53-56.
LI T F, WANG J, ZHOU C C, et al. Gangue in main mineable coal seams and resources utilization research in huainan mining area[J]. Coal Geology of China, 2015, 27(8): 53-56 (in Chinese).
[2] CAO Z, CAO Y D, DONG H J, et al. Effect of calcination condition on the microstructure and pozzolanic activity of calcined coal gangue[J]. International Journal of Mineral Processing, 2016, 146: 23-28.
[3] 李超,赵亮,惠晓梅,等.煤矸石动态煅烧活化的影响因素[J].环境工程学报,2017,11(7):4349-4354.
LI C, ZHAO L, HUI X M, et al. Influence factors of dynamic calcinations for coal gangue activation[J]. Chinese Journal of Environmental Engineering, 2017, 11(7): 4349-4354 (in Chinese).
[4] WANG A G, LIU P, MO L W, et al. Mechanism of thermal activation on granular coal gangue and its impact on the performance of cement mortars[J]. Journal of Building Engineering, 2022, 45: 103616.
[5] ZHOU S X, DONG J L, YU L H, et al. Effect of activated coal gangue in North China on the compressive strength and hydration process of cement[J]. Journal of Materials in Civil Engineering, 2019, 31(4): 4019022.
[6] 张长森,邓育新,吴其胜.微波活化煤矸石反应活性及胶凝性能[J].环境工程学报,2013,7(8):3170-3174.
ZHANG C S, DENG Y X, WU Q S. Reactivity and cementitious properties of coal gangue by microwave irradiation[J]. Chinese Journal of Environmental Engineering, 2013, 7(8): 3170-3174 (in Chinese).
[7] CHEN J X, GUAN X, ZHU M Y, et al. Mechanism on activation of coal gangue admixture[J]. Advances in Civil Engineering, 2021, 2021: 5436482.
[8] GUAN X, CHEN J X, ZHU M Y, et al. Performance of microwave-activated coal gangue powder as auxiliary cementitious material[J]. Journal of Materials Research and Technology, 2021, 14: 2799-2811.
[9] 赵志曼,宋万明,董斌,等.微波辐照活化煤矸石-硅酸盐水泥体系试验研究[J].材料导报,2011,25(s1):474-476.
ZHAO Z M, SONG W M, DONG B, et al. Effect of microwave radiation activation coal gangue to Portland cement system properties[J]. Materials Review, 2011, 25(s1): 474-476 (in Chinese).
[10] MA H Q, ZHU H G, WU C, et al. Study on compressive strength and durability of alkali-activated coal gangue-slag concrete and its mechanism[J]. Powder Technology, 2020, 368: 112-124.
[11] 邢军,周梅,张倩.热活化煤矸石矿物掺合料对混凝土抗渗和抗冻性能影响[J].硅酸盐通报,2015,34(9):2696-2701.
XING J, ZHOU M, ZHANG Q. Effect of thermal activated coal gangue mineral admixtures on impermeability and frost resistance of concrete[J]. Bulletin of the Chinese Ceramic Society, 2015, 34(9): 2696-2701 (in Chinese).
[12] 白春,麻凤海,刘书贤,等.煅烧煤矸石粉掺合料制备及对混凝土性能影响[J].非金属矿,2017,40(2):38-41.
BAI C, MA F H, LIU S X, et al. Effect of the preparation process of calcined coal gangue powder admixture on concrete performance[J]. Non-Metallic Mines, 2017, 40(2): 38-41 (in Chinese).
[13] WANG Y Z, TAN Y, WANG Y C, et al. Mechanical properties and chloride permeability of green concrete mixed with fly ash and coal gangue[J]. Construction and Building Materials, 2020, 233: 117166.[14] 赵旭东,刘开志,陈杰,等.活化煤矸石生态型混凝土长期性能及水化特性的研究[J].硅酸盐通报,2020,39(6):1757-1764.
ZHAO X D, LIU K Z, CHEN J, et al. Long-term performance and hydration characteristics of activated coal gangue ecological concrete[J]. Bulletin of the Chinese Ceramic Society, 2020, 39(6): 1757-1764 (in Chinese).
[15] QIU J S, ZHOU Y X, GUAN X, et al. The influence of fly ash content on ITZ microstructure of coal gangue concrete[J]. Construction and Building Materials, 2021, 298: 123562.
[16] 李三,彭小芹,苟菁,等.矿物掺合料对地聚合物抗冻性能的影响[J].材料导报,2018,32(10):1711-1715.
LI S, PENG X Q, GOU J, et al. Effect of mineral admixtures incorporation on frost resistance of geopolymer[J]. Materials Review, 2018, 32(10): 1711-1715 (in Chinese).
[17] QIU J S, ZHU M Y, ZHOU Y X, et al. Effect and mechanism of coal gangue concrete modification by fly ash[J]. Construction and Building Materials, 2021, 294: 123563.
[18] 胡晓娜,赵志曼,王倩,等.微波辐照活化高岭质矿物研究进展[J].矿产综合利用,2013(2):20-23.
HU X N, ZHAO Z M, WANG Q, et al. Research progress of activating kaolin mineral by microwave irradiation[J]. Multipurpose Utilization of Mineral Resources, 2013(2): 20-23 (in Chinese).
[19] 吴中伟.混凝土科学技术近期发展方向的探讨[J].硅酸盐学报,1979,7(3):262-270.
WU Z W. An approach to the recent trends of concrete science and technology[J]. Journal of the Chinese Ceramic Society, 1979, 7(3): 262-270 (in Chinese).
[20] ZHANG Y Y, XU L, SEETHARAMAN, S. et al. Effects of chemistry and mineral on structural evolution and chemical reactivity of coal gangue during calcination: towards efficient utilization[J]. Materials and Structures, 2015, 48, 2779-2793.
[21] 曹永丹,李彦鑫,张金山,等.细度和煅烧温度对煤矸石火山灰活性及微观结构的影响[J].硅酸盐学报,2017,45(8):1153-1158.
CAO Y D, LI Y X, ZHANG J S, et al. Effects of calcination temperature and particle size on pozzolanic activity and microstructure of coal gangue[J]. Journal of the Chinese Ceramic Society, 2017, 45(8): 1153-1158 (in Chinese).
[22] 姚苏琴,查文华,刘新权,等.萍乡废弃煤矸石理化特性及热活化性能研究[J].硅酸盐通报,2021,40(7):2280-2287.
YAO S Q, ZHA W H, LIU X Q, et al. Physicochemical and thermal activation properties of waste coal gangue in Pingxiang mining area[J]. Bulletin of the Chinese Ceramic Society, 2021, 40(7): 2280-2287 (in Chinese).