Macro-Mechanical Properties and Microscopic-Mechanism of Coal Gangue Mixed Sand Concrete

doi:10.16552/j.cnki.issn1001-1625.2025.0941

Abstract

Abstract:

In this study， coal gangue mixed sand concrete （CGMSG） was prepared by fully replacing river sand with coal gangue machine-made sand and aeolian sand at a mass ratio of 6∶4， and replacing natural coarse aggregate with coal gangue coarse aggregate at different mass fraction （0%， 20%， 40%， 60%， 80%， and 100%）. The basic mechanical properties and water absorption rate of CGMSG were measured， and the hydration mechanism and microscopic pore structure were studied by combining X-ray diffraction and nuclear magnetic resonance technology. The results show that the compressive strength and splitting tensile strength of CGMSG decrease with the increase of water-binder ratio and coal gangue coarse aggregate content， while the water absorption rate increases with the increase of both factors. The GM（1，1） grey prediction model established based on compressive strength can well reflect the development law of its strength. When the content of coal gangue coarse aggregate is 40% to 60%， the activity of coal gangue and the hydration of cement can be maximally exerted. Under different water-binder ratios and coal gengue coarse aggregate content， both the porosity and average pore size of CGMSG increase with the increase of water-binder ratio and coal gangue coarse aggregate content. The macro-pore porosity has the highest correlation with compressive strength， and the total pore volume has the lowest correlation with compressive strength.

Key words: coal gangue mixed sand concrete, grey prediction model, grey correlation analysis, mechanical property, microscopic mechanism

CLC Number:

TU528

ZOU Renhua, HU Xiaolong, FENG Zeping, NIU Gaohui, QIU Jisheng. Macro-Mechanical Properties and Microscopic-Mechanism of Coal Gangue Mixed Sand Concrete[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2026, 45(4): 1266-1281.

Figures/Tables 27

References 26

[1]	甄强，郑锋. 煤的伴生资源煤矸石的综合利用［J］. 自然杂志， 2015， 37（2）： 121-128.
	ZHEN Q， ZHENG F. Comprehensive utilization of coal gangue as an associated resource with coal［J］. Chinese Journal of Nature， 2015， 37（2）： 121-128 （in Chinese）.
[2]	贾敏. 煤矸石综合利用研究进展［J］. 矿产保护与利用， 2019， 39（4）： 46-52.
	JIA M. The current situation research on comprehensive utilization of coal gangue［J］. Conservation and Utilization of Mineral Resources， 2019， 39（4）： 46-52 （in Chinese）.
[3]	国家统计局.中华人民共和国2022年国民经济和社会发展统计公报［J］. 中国统计， 2023（3）： 12-29.
	National Bureau of Statistics of the People's Republic of China. Statistical communique on national economic and social development of the people’s republic of China in 2022［J］. China Statistics， 2023（3）：12-29 （in Chinese）
[4]	张锂，韩国才，陈慧，等. 黄土高原煤矿区煤矸石中重金属对土壤污染的研究［J］. 煤炭学报， 2008， 33（10）： 1141-1146.
	ZHANG L， HAN G C， CHEN H， et al. Study on heavy metal contaminants in soil come from coal mining spoil in the Loess Plateau［J］. Journal of China Coal Society， 2008， 33（10）： 1141-1146 （in Chinese）.
[5]	梁冰，薛强，刘晓丽. 煤矸石中硫酸盐对地下水污染的环境预测［J］. 煤炭学报， 2003， 28（5）： 527-530.
	LIANG B， XUE Q， LIU X L. Environmental prediction on coal mine spoil of sulphateck for groundwater pollution［J］. Journal of China Coal Society， 2003， 28（5）： 527-530 （in Chinese）.
[6]	牟献友，谷攀. 国内风积沙工程特性研究综述［J］. 内蒙古农业大学学报（自然科学版）， 2010， 31（1）： 307-310.
	MOU X Y， GU P. Review on engineering characteristics of wind-blown sand［J］. Journal of Inner Mongolia Agricultural University （Natural Science Edition）， 2010， 31（1）： 307-310 （in Chinese）.
[7]	LIU X Y， LIU R D， LYU K， et al. A quantitative evaluation of size and shape characteristics for desert sand particles［J］. Minerals， 2022， 12（5）： 581.
[8]	LUO F J， HE L， PAN Z， et al. Effect of very fine particles on workability and strength of concrete made with dune sand［J］. Construction and Building Materials， 2013， 47： 131-137.
[9]	YU L L， XIA J W， XIA Z， et al. Study on the mechanical behavior and micro-mechanism of concrete with coal gangue fine and coarse aggregate［J］. Construction and Building Materials， 2022， 338： 127626.
[10]	GAO S， ZHANG S M， GUO L H. Application of coal gangue as a coarse aggregate in green concrete production： a review［J］. Materials， 2021， 14（22）： 6803.
[11]	李瑜. 煤矸石制砂的优势［J］. 砖瓦， 2020（1）： 72.
	LI Y. Advantages of making sand from coal gangue［J］. Brick-Tile， 2020（1）： 72 （in Chinese）.
[12]	邓焙元，刘清，韩风霞，等. 风积砂混凝土力学性能研究综述［J］. 混凝土， 2021（6）： 47-52.
	DENG B Y， LIU Q， HAN F X， et al. Review of research on mechanics and durability of aeolian sand concrete［J］. Concrete， 2021（6）： 47-52 （in Chinese）.
[13]	刘旭军，魏平平，李睿妮，等. 风积砂混凝土强度及耐久性试验研究［J］. 工程与建设， 2023， 37（5）： 1585-1587+1599.
	LIU X J， WEI P P， LI R N， et al. Experimental study on strength and durability of aeolian sand concrete［J］. Engineering and Construction， 2023， 37（5）： 1585-1587+1599 （in Chinese）.
[14]	ZHU L L， ZHENG M L， ZHANG W， et al. Multicomponent cementitious materials optimization， characteristics investigation and reinforcement mechanism analysis of high-performance concrete with full aeolian sand［J］. Journal of Building Engineering， 2024， 84： 108562.
[15]	ZHANG M H， ZHU X Z， SHI J Y， et al. Utilization of desert sand in the production of sustainable cement-based materials： a critical review［J］. Construction and Building Materials， 2022， 327： 127014.
[16]	LAKUSIC S. Influence of pore structure characteristics on the strength of aeolian sand concrete［J］. Journal of the Croatian Association of Civil Engineers， 2024， 76（1）： 35-45.
[17]	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.
[18]	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.
[19]	GUAN X， CHEN J X， QIU J S， et al. Damage evaluation method based on ultrasound technique for gangue concrete under freezing-thawing cycles［J］. Construction and Building Materials， 2020， 246： 118437.
[20]	GUAN X， QIU J S， SONG H T， et al. Stress-strain behaviour and acoustic emission characteristic of gangue concrete under axial compression in frost environment［J］. Construction and Building Materials， 2019， 220： 476-488.
[21]	QIAN S L. A review study on performance improvement of coal gangue as coarse aggregate in concrete［J］. Journal of Engineering Research and Reports， 2023， 25（11）： 142-148.
[22]	周梅，白金婷，薛忠泉. 自燃煤矸石全集料混凝土强度研究［J］. 建筑结构， 2011， 41（增刊2）： 200-202.
	ZHOU M， BAI J T， XUE Z Q. Study on strength of self-igniting gangue aggregate concrete［J］. Building Structure， 2011， 41（supplement 2）： 200-202 （in Chinese）.
[23]	刘德清，王建华，李玉坤. 煤矸石混凝土劈裂抗拉强度的试验研究［J］. 房材与应用， 1997， 25（1）： 38-46.
	LIU D Q， WANG J H， LI Y K. Experimental study on splitting tensile strength of coal gangue concrete［J］. Housing Materials & Applications， 1997， 25（1）： 38-46 （in Chinese）.
[24]	王发洲. 高性能轻集料混凝土研究与应用［D］. 武汉：武汉理工大学， 2003.
	WANG F Z. Research and application of high performance lightweight aggregate concrete［D］. Wuhan： Wuhan University of Technology， 2003 （in Chinese）.
[25]	段晓牧，夏军武，杨建平. 煤矸石细集料对水泥浆体微观结构的影响及其作用机理［J］. 建筑材料学报， 2014， 17（4）： 700-705.
	DUAN X M， XIA J W， YANG J P. Influence of coal gangue fine aggregate on microstructure of cement mortar and its action mechanism［J］. Journal of Building Materials， 2014， 17（4）： 700-705 （in Chinese）.
[26]	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）.

Fineness/%	Initial settingtime/min	Final settingtime/min	Specific surfacearea/（m²·kg^-1）	Flexural strength/MPa		Compressive strength/MPa
Fineness/%	Initial settingtime/min	Final settingtime/min	Specific surfacearea/（m²·kg^-1）	3 d	28 d	3 d	28 d
3.65	168	255	369	3.1	7.8	21.5	47.6

Fineness/%	Initial settingtime/min	Final settingtime/min	Specific surfacearea/（m²·kg^-1）	Flexural strength/MPa		Compressive strength/MPa
Fineness/%	Initial settingtime/min	Final settingtime/min	Specific surfacearea/（m²·kg^-1）	3 d	28 d	3 d	28 d
3.65	168	255	369	3.1	7.8	21.5	47.6

Material	Mass fraction/%
Material	Al₂O₃	SiO₂	Fe₂O₃	CaO	MgO	Other
Aeolian sand	7.56	82.15	4.95	3.22	0.56	1.56
Gangue sand	36.25	48.23	6.58	6.02	0.88	2.04

Material	Mass fraction/%
Material	Al₂O₃	SiO₂	Fe₂O₃	CaO	MgO	Other
Aeolian sand	7.56	82.15	4.95	3.22	0.56	1.56
Gangue sand	36.25	48.23	6.58	6.02	0.88	2.04

Sample	Mix proportion/（kg·m^-3）
Sample	Water-binderratio	Water	Cement	Mixed sand	Macadam	Coal gangue	Water reducer	Air-entraining agent
S35C0	0.35	170	485.7	627.9	1 116.3	0	3.89	0.97
S45C0	0.45	170	377.8	666.8	1 185.4	0	3.02	0.76
S45C20	0.45	170	377.8	666.8	948.3	211.1	3.02	0.76
S45C40	0.45	170	377.8	666.8	711.3	422.3	3.02	0.76
S45C60	0.45	170	377.8	666.8	474.2	633.4	3.02	0.76
S45C80	0.45	170	377.8	666.8	237.1	844.6	3.02	0.76
S45C100	0.45	170	377.8	666.8	0	1 055.7	3.02	0.76
S55C0	0.55	170	309.1	691.5	1 229.4	0	2.47	0.62