Preparation and Formation Mechanism of Ultra-Early Strength Environmental-Friendly Steel Slag Micro Powder UHPC

doi:10.16552/j.cnki.issn1001-1625.2025.0647

Abstract

Abstract:

To enhance the rapid repair capability of concrete pavements after damage and strengthen the reuse of solid waste resources， based on the previously developed environmental-friendly steel slag micro powder ultra-high performance concrete （UHPC）， nine groups of ultra-early strength steel slag micro powder UHPC were prepared using an orthogonal experimental design. The influencing factors included the replacement rate of ordinary Portland cement （OPC） for sulphoaluminate cement （SAC）， the content of early-strength agent lithium carbonate， the content of steel fiber， and the content of setting regulator borax. By testing initial setting time， compressive strength， and flexural strength at different ages， the influence patterns of each factor were analyzed， and the optimal mix ratio of ultra-early strength UHPC was determined. Additionally， field emission scanning electron microscopy （SEM） and X-ray diffractometer （XRD） were used to characterize the micro-morphology and phase composition of ultra-early strength UHPC at various ages. The results show that with the increase of OPC replacement rate， the setting time of UHPC decreases first and then increases， and the mechanical properties show a downward trend. The excessively rapid early hydration reaction of the SAC-OPC system leads to incomplete hydration， resulting in lower later-age compressive strength compare to the reference group. At a low OPC replacement rate， the SAC-OPC system UHPC prepared from steel slag micro powder still has relatively low alkalinity. Ettringite（AFt） is present in the hydration products， but calcium hydroxide（CH） is not observed. Moreover， the content of AFt gradually decreases with increasing OPC replacement rate. As hydration reaction proceeds， the pores， voids， and cracks in the matrix of ultra-early strength UHPC gradually reduce， and the structure tends to be dense. Based on the analysis of the influences of various factors on the mechanical properties and construction performance of SAC-OPC system concrete， the ultra-early strength environmental-friendly steel slag micro powder UHPC with initial setting time of 30 min and compressive strength and flexural strength of 39.6 and 11.2 MPa for 3 h under conventional curing conditions is prepared.

Key words: ultra-high performance concrete, steel slag micro powder, SAC-OPC system, ultra-early strength, mechanical property, formation mechanism

CLC Number:

TU528

TANG Xianyuan, REN Bowen, HU Bingqian, LIU Dacheng, FENG Meijie. Preparation and Formation Mechanism of Ultra-Early Strength Environmental-Friendly Steel Slag Micro Powder UHPC[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2026, 45(1): 191-201.

Figures/Tables 15

References 20

[1]	交通运输部. 公路工程水泥混凝土用快速修补材料第1部分：水泥基修补材料： JT/T 1211.1—2018［S］. 北京：人民交通出版社， 2018.
	Ministry of Transport of the People’s Republic of China. Rapid repairing material of cement concrete for highway engineering- Part 1： cementitious repairing materia： JT/T 1211.1—2018［S］. Beijing： China Communications Press， 2018 （in Chinese）.
[2]	YU R， ZHANG X Y， HU Y W， et al. Development of a rapid hardening ultra-high performance concrete （R-UHPC）： from macro properties to micro structure［J］. Construction and Building Materials， 2022， 329： 127188. DOI URL
[3]	周　渊，王　雄，秦　廉，等. 快硬UHPC的研发及其在道路快速维养工程中的示范应用［J］. 新型建筑材料， 2021， 48（1）： 10-14.
	ZHOU Y， WANG X， QIN L， et al. Development of rapid hardening UHPC and its application in road rehabilitation［J］. New Building Materials， 2021， 48（1）： 10-14 （in Chinese）.
[4]	丁　斌，欧阳利军，房钰柯. 混凝土早强性能研究进展和展望［J］. 混凝土与水泥制品， 2020（9）： 24-29.
	DING B， OUYANG L J， FANG Y K. Review and prospect of early strength performance of concrete［J］. China Concrete and Cement Products， 2020（9）： 24-29 （in Chinese）.
[5]	于　峰，张　扬，王旭良，等. 全集料钢渣混凝土抗压强度试验研究［J］. 应用基础与工程科学学报， 2018， 26（4）： 854-862.
	YU F， ZHANG Y， WANG X L， et al. Experimental study on compressive strength of full steel slag aggregate concrete［J］. Journal of Basic Science and Engineering， 2018， 26（4）： 854-862 （in Chinese）.
[6]	唐咸远，胡贤松，罗　杰，等. 改性材料及其掺量对超高性能混凝土力学性能的影响［J］. 中国粉体技术， 2024， 30（1）： 153-160.
	TANG X Y， HU X S， LUO J， et al. Effects of modified materials and its contents on mechanical property of ultra-high performance concrete［J］. China Powder Science and Technology， 2024， 30（1）： 153-160 （in Chinese）.
[7]	TANG X Y， FENG C Z， REN B W， et al. Experimental study on the triaxial compressive properties of UHPC with coarse aggregate steel slag micro powder under different confining pressures［J］. Scientific Reports， 2025， 15（1）： 12343. DOI
[8]	TANG X Y， HE B B， YANG B， et al. Experimental study on axial stress-strain behaviour of steel fibre-reinforced steel slag micropowder UHPC［J］. Applied Sciences， 2023， 13（15）： 8807. DOI URL
[9]	龚建清，郭万里，龚　啸，等. 碳酸锂与纳米碳酸钙对UHPC早期力学性能的影响［J］. 硅酸盐通报， 2020， 39（11）： 3463-3472.
	GONG J Q， GUO W L， GONG X， et al. Effects of lithium carbonate and nano-calcium carbonate on early mechanical properties of UHPC［J］. Bulletin of the Chinese Ceramic Society， 2020， 39（11）： 3463-3472 （in Chinese）.
[10]	郭金波，郭妍妍，丁向群，等. 无机盐-络合剂-聚合物复合早强剂对水泥早期水化性能的影响［J］. 混凝土， 2024（6）： 143-145.
	GUO J B， GUO Y Y， DING X Q， et al. Effect of inorganic salt-complex agent-polmer on early hydration properties of cement［J］. Concrete， 2024（6）： 143-145 （in Chinese）.
[11]	WU X H， HU L E， GUO F C， et al. Analysis of different early strength agents on the performance of prefabricated UHPC［J］. Materials， 2024， 17（11）： 2481. DOI URL
[12]	WEI K F， XU G， YANG J， et al. Study on mechanical and shrinkage properties of ES-UHPC［J］. Construction and Building Materials， 2023， 377： 131137. DOI URL
[13]	邹永泉，仝亚刚，李　征. 高掺量SBR的粒径对硫铝酸盐水泥-石膏砂浆性能的影响［J］. 混凝土， 2024（11）： 145-149+154.
	ZOU Y Q， TONG Y G， LI Z. Effect of particle size of high content SBR on the properties of sulfoaluminate cement-gypsum mortar［J］. Concrete， 2024（11）： 145-149+154 （in Chinese）.
[14]	魏定邦，丁　民，任国斌，等. 硫铝酸盐复合水泥体系水化特征研究［J］. 材料导报， 2018， 32（增刊2）： 492-497.
	WEI D B， DING M， REN G B， et al. Study on hydration properties of composite cementitious material based on sulphoaluminate［J］. Materials Reports， 2018， 32（supplement 2）： 492-497 （in Chinese）.
[15]	杨　清，张秀芝，刘　迪，等. 普通硅酸盐-硫铝酸盐复合胶凝体系水化性能和机理研究［J］. 材料导报， 2018， 32（增刊2）： 517-521+534.
	YANG Q， ZHANG X Z， LIU D， et al. Hydration properties and mechanism of Portland cement-sulphoaluminate cement compound system［J］. Materials Reports， 2018， 32（supplement 2）： 517-521+534 （in Chinese）.
[16]	李传习，夏雨航，王圣杰，等. 初凝超30 min超早强UHPC制备及其机理［J］. 硅酸盐通报， 2023， 42（5）： 1630-1639.
	LI C X， XIA Y H， WANG S J， et al. Preparation and mechanism of super-early-strength UHPC with initial setting time over 30 min［J］. Bulletin of the Chinese Ceramic Society， 2023， 42（5）： 1630-1639 （in Chinese）.
[17]	杨　云. 外掺硫铝酸盐水泥对混凝土早期强度影响研究［D］. 重庆：重庆大学， 2019.
	YANG Y. Effect of the additive with sulphoaluminate cement on early strength of concrete［D］. Chongqing： Chongqing University， 2019 （in Chinese）.
[18]	国家市场监督管理总局，国家标准化管理委员会. 水泥胶砂强度检验方法（ISO法）： GB/T 17671—2021［S］. 北京：中国标准出版社， 2021.
	State Administration for Market Regulation， Standardization Administration of the People’s Republic of China. Test method of cement mortar strength（ISO method）： GB/T 17671—2021［S］. Beijing： Standards Press of China， 2021 （in Chinese）.
[19]	国家市场监督管理总局，国家标准化管理委员会. 水泥标准稠度用水量、凝结时间与安定性检验方法： GB/T 1346—2024［S］. 北京：中国标准出版社， 2024.
	State Administration for Market Regulation， Standardization Administration of the People’s Republic of China. Test methods for water requirement of standard consistency， setting time and soundness of the Portland cement： GB/T 1346—2024［S］. Beijing： Standards Press of China， 2024 （in Chinese）.
[20]	姚兆龙，马　超，谢孟奇，等. 钢渣微粉-硅灰水泥基胶凝材料的水化机理研究［J］. 金属矿山， 2025（3）： 278-285.
	YAO Z L， MA C， XIE M Q， et al. Study on hydration mechanism of steel slag powder-silica fume cement-based cementitious materials［J］. Metal Mine， 2025（3）： 278-285 （in Chinese）.

Materials	Mass fraction/%							Specific surface area/（m²·kg^-1）
Materials	SiO₂	Al₂O₃	Fe₂O₃	CaO	MgO	SO₃	Other	Specific surface area/（m²·kg^-1）
OPC	21.86	4.25	2.72	63.65	2.14	2.43	2.95	300
SAC	12.30	21.33	1.53	50.12	2.06	12.33	0.33	550
SSMP	17.15	5.60	22.70	43.35	6.00	—	5.20	620
SF	93.58	0.51	0.58	1.97	0.25	—	3.11	22 000

Materials	Mass fraction/%							Specific surface area/（m²·kg^-1）
Materials	SiO₂	Al₂O₃	Fe₂O₃	CaO	MgO	SO₃	Other	Specific surface area/（m²·kg^-1）
OPC	21.86	4.25	2.72	63.65	2.14	2.43	2.95	300
SAC	12.30	21.33	1.53	50.12	2.06	12.33	0.33	550
SSMP	17.15	5.60	22.70	43.35	6.00	—	5.20	620
SF	93.58	0.51	0.58	1.97	0.25	—	3.11	22 000

Sample No.	Mix proportion/（kg·m^-3）							Mass fraction/%			Volume fraction/%
Sample No.	OPC	SAC	SF	SSMP	MRS	Water	PCE	LC	NC	Bx	Steel fiber
T1-10	72	648	380	140	760	225	12.5	0.075	2	0.09	0
T2-10	72	648	380	140	760	225	12.5	0.100	2	0.18	1
T3-10	72	648	380	140	760	225	12.5	0.125	2	0.27	2
T4-20	144	576	380	140	760	225	12.5	0.075	2	0.27	1
T5-20	144	576	380	140	760	225	12.5	0.100	2	0.09	2
T6-20	144	576	380	140	760	225	12.5	0.125	2	0.18	0
T7-30	216	504	380	140	760	225	12.5	0.075	2	0.18	2
T8-30	216	504	380	140	760	225	12.5	0.100	2	0.27	0
T9-30	216	504	380	140	760	225	12.5	0.125	2	0.09	1
T0	0	720	380	140	760	225	12.5	0.100	2	0	1

Sample No.	Mix proportion/（kg·m^-3）							Mass fraction/%			Volume fraction/%
Sample No.	OPC	SAC	SF	SSMP	MRS	Water	PCE	LC	NC	Bx	Steel fiber
T1-10	72	648	380	140	760	225	12.5	0.075	2	0.09	0
T2-10	72	648	380	140	760	225	12.5	0.100	2	0.18	1
T3-10	72	648	380	140	760	225	12.5	0.125	2	0.27	2
T4-20	144	576	380	140	760	225	12.5	0.075	2	0.27	1
T5-20	144	576	380	140	760	225	12.5	0.100	2	0.09	2
T6-20	144	576	380	140	760	225	12.5	0.125	2	0.18	0
T7-30	216	504	380	140	760	225	12.5	0.075	2	0.18	2
T8-30	216	504	380	140	760	225	12.5	0.100	2	0.27	0
T9-30	216	504	380	140	760	225	12.5	0.125	2	0.09	1
T0	0	720	380	140	760	225	12.5	0.100	2	0	1

Sample No.	Compressive strength/MPa					Flexural strength/MPa
Sample No.	3 h	6 h	1 d	3 d	28 d	3 h	6 h	1 d	3 d	28 d
T1-10	37.5	46.4	55.4	70.1	113.6	8.4	8.7	9.4	9.5	20.2
T2-10	40.2	48.8	56.3	75.4	112.5	7.3	8.1	9.0	12.5	22.6
T3-10	42.1	53.3	63.2	78.3	123.3	13.4	13.6	14.0	17.8	23.7
T4-20	35.3	47.4	53.2	67.2	111.8	8.1	8.4	11.5	12.1	18.1
T5-20	37.1	46.8	61.2	73.5	119.1	8.2	10.2	15.3	15.3	22.9
T6-20	37.7	38.4	53.1	70.5	115.5	8.1	8.8	9.1	10.1	20.5
T7-30	23.4	37.3	46.7	60.0	106.4	9.3	11.9	12.5	13.0	23.6
T8-30	35.2	35.7	45.3	56.1	94.0	6.3	7.3	9.0	8.8	16.5
T9-30	35.2	37.7	45.3	65.9	101.3	6.1	7.5	9.1	9.7	16.8
Average	36.0	43.5	53.3	68.6	110.8	8.4	9.4	11.0	12.1	20.5
T0	35.0	44.4	55.0	80.5	130.5	6.4	8.5	9.8	10.0	22.7