Mechanical Properties and Ratio Optimization of Mineral Admixture Wet Shotcrete under Low Temperature Curing

Abstract

Abstract: To systematically study the effects of fly ash content, silica fume content and curing temperature on the mechanical properties of wet shotcrete, the range and variance analysis of the compressive strength of wet shotcrete were carried out by designing orthogonal tests. The results show that the compressive strength of wet shotcrete increases with the increase of curing age, but the increase rate slows down with the extension of curing ages.The compressive strength of wet shotcrete can be effectively improved by the increase content of silica fume and pulverized coal, but when the content of fly ash exceeds 10% (mass fraction, the same below), the increase of fly ash content has no significant influence on the later compressive strength of concrete. The order of the influence of the three factors on the compressive strength of wet shotcrete is silica fume content＞curing temperature＞fly ash content. The sensitivity of the compressive strength of wet shotcrete to mineral admixtures is positively correlated with the curing temperature. The improvement effect of mineral admixtures on compressive strength of wet shotcrete increases with the increase of curing temperature. With the increase of curing temperature, a large number of flocculent cementitious substances are generated. The hydration products bond more densely, and the compressive strength and bearing performance of concrete are further enhanced. The established multiple nonlinear models can predict the compressive strength of concrete, and wet shotcrete has the best compressive strength when the silica fume content, fly ash content and curing temperature are 15%, 15% and 10 ℃, respectively.

Key words: wet shotcrete, mineral admixture, compressive strength, curing temperature, orthogonal test, microstructure

CLC Number:

TD262
TU528

YANG Fan, ZHANG Youfeng, YU Yao. Mechanical Properties and Ratio Optimization of Mineral Admixture Wet Shotcrete under Low Temperature Curing[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(5): 1589-1598.

References

[1] 孟科,韩斌,姚松.湿喷混凝土的管道输送研究[J].采矿技术,2019,19(3):94-97.
MENG K, HAN B, YAO S. Study on pipeline transportation of wet shotcrete[J]. Mining Technology, 2019, 19(3): 94-97 (in Chinese).
[2] 于少峰.初温效应下湿喷混凝土流变行为及其管输特性研究[D].北京:北京科技大学,2019.
YU S F. Rheology behavior and pipe flow performance of wet-sprayed shotcrete under initial temperature effect[D]. Beijing: University of Science and Technology Beijing, 2019 (in Chinese).
[3] 赵国彦,马举,彭康,等.基于响应面法的高寒矿山充填配比优化[J].北京科技大学学报,2013,35(5):559-565.
ZHAO G Y, MA J, PENG K, et al. Mix ratio optimization of alpine mine backfill based on the response surface method[J]. Journal of University of Science and Technology Beijing, 2013, 35(5): 559-565 (in Chinese).
[4] VELAY-LIZANCOS M, MARTINEZ-LAGE I, AZENHA M, et al. Influence of temperature in the evolution of compressive strength and in its correlations with UPV in eco-concretes with recycled materials[J]. Construction and Building Materials, 2016, 124: 276-286.
[5] PICHLER C, SCHMID M, TRAXL R, et al. Influence of curing temperature dependent microstructure on early-age concrete strength development[J]. Cement and Concrete Research, 2017, 102: 48-59.
[6] CUI S G, LIU P, CUI E Q, et al. Experimental study on mechanical property and pore structure of concrete for shotcrete use in a hot-dry environment of high geothermal tunnels[J]. Construction and Building Materials, 2018, 173: 124-135.
[7] 李克庆,胡亚飞,韩斌,等.低温下湿喷混凝土强度预测与强度损伤[J].中南大学学报(自然科学版),2021,52(5):1581-1590.
LI K Q, HU Y F, HAN B, et al. Strength prediction and strength damage of wet shotcrete at low temperature[J]. Journal of Central South University (Science and Technology), 2021, 52(5): 1581-1590 (in Chinese).
[8] 王永定,温震江,杨晓炳,等.粉煤灰-矿渣基固结粉胶凝材料开发与配比优化研究[J].矿业研究与开发,2019,39(5):88-94.
WANG Y D, WEN Z J, YANG X B, et al. Study on development and ratio optimization of cementing material of fly ash-slag based consolidated powder[J]. Mining Research and Development, 2019, 39(5): 88-94 (in Chinese).
[9] 张明明,王社良,张世民,等.矿物掺合料对再生混凝土力学性能的影响[J].硅酸盐通报,2017,36(5):1505-1511.
ZHANG M M, WANG S L, ZHANG S M, et al. Effect of mineral admixture on the mechanical properties of the RAC activity[J]. Bulletin of the Chinese Ceramic Society, 2017, 36(5): 1505-1511 (in Chinese).
[10] 张一帆,杜红秀,石丽娜.碳纤维及硅灰掺量对活性粉末混凝土强度和温敏性的影响[J].混凝土,2019(7):79-81.
ZHANG Y F, DU H X, SHI L N. Effect of carbon fiber content and silica ash content on strength and temperature sensitivity of reactive powder concrete[J]. Concrete, 2019(7): 79-81 (in Chinese).
[11] 胡亚飞,李克庆,韩斌,等.复合胶凝体系对尾砂湿喷混凝土强度的影响及其配比优化[J].中南大学学报(自然科学版),2021,52(11):3999-4009.
HU Y F, LI K Q, HAN B, et al. Influence and mix proportion optimization of composite cementation system on strength of wet shotcrete with tailings[J]. Journal of Central South University (Science and Technology), 2021, 52(11): 3999-4009 (in Chinese).
[12] 王辉,刘旭辉,蔡升宇,等.粉煤灰掺量对高性能自密实混凝土抗压强度发展影响分析[J].硅酸盐通报,2021,40(5):1573-1578.
WANG H, LIU X H, CAI S Y, et al. Influence of fly ash content on compressive strength development of high performance self-compacting concrete[J]. Bulletin of the Chinese Ceramic Society, 2021, 40(5): 1573-1578 (in Chinese).
[13] 何淅淅,孔令钊,周笋.低温养护粉煤灰混凝土棱柱抗压性能的试验研究[J].建筑结构,2020,50(13):38-43.
HE X X, KONG L Z, ZHOU S. Experimental study on compressive properties of fly ash concrete prism under low temperature curing[J]. Building Structure, 2020, 50(13): 38-43 (in Chinese).
[14] 李恒,王家滨,郭庆军,等.矿物掺合料再生混凝土力学性能研究[J].硅酸盐通报,2020,39(8):2608-2614.
LI H, WANG J B, GUO Q J, et al. Mechanical properties of recycled aggregate concrete with mineral admixture[J]. Bulletin of the Chinese Ceramic Society, 2020, 39(8): 2608-2614 (in Chinese).
[15] 吴炜,胡亚飞,陈建新,等.外加料对尾砂湿喷混凝土强度影响的试验研究[J].矿业研究与开发,2020,40(5):84-88.
WU W, HU Y F, CHEN J X, et al. Experimental study on the influence of additives on the strength of wet shotcrete with tailings[J]. Mining Research and Development, 2020, 40(5): 84-88 (in Chinese).
[16] 魏向明,董超,冯竟竟,等.双掺粉煤灰矿渣泡沫混凝土性能试验研究[J].混凝土与水泥制品,2019(7):63-66.
WEI X M, DONG C, FENG J J, et al. Experimental research on properties of foamed concrete mixed with fly ash and slag[J]. China Concrete and Cement Products, 2019(7): 63-66 (in Chinese).
[17] 张明天,陈结,姜德义,等.湿喷混凝土支护强度影响规律探究及改进[J].中国安全生产科学技术,2021,17(9):25-31.
ZHANG M T, CHEN J, JIANG D Y, et al. Research on influence laws for support strength of wet shotcrete and improvement[J]. Journal of Safety Science and Technology, 2021, 17(9): 25-31 (in Chinese).