Yafei Hu^1,2, Keqing Li^1,2, Bo Zhang^1,2, Bin Han^1,2,*

Journal of Renewable Materials, Vol.11, No.9, pp. 3463-3484, 2023, DOI:10.32604/jrm.2023.027532

Abstract The super-fine particle size of tailings is its drawback as a recycled resource, which is reflected in the low strength of the new construction and industrial materials formed when it is mixed with cement and other cementitious materials. Therefore, it is crucial to study the effect of tailings particle size and cementitious material on the strength of tailings wet shotcrete (TWSC) and to investigate the optimal mix proportion. In this paper, a multivariate nonlinear response model was constructed by conducting central composite experiments to investigate the effect of different factors on the strength of TWSC. The strength prediction and mix… More >

Jinxing Wang^1,2,3, Yingjie Yang^1,2,3, Xiaolin Yang^1,2,3, Huazhe Jiao^1,2,3,4,*, Qi Wang^1,2,3, Liuhua Yang^1,2,3, Jianxin Yu^1,2,3, Fengbin Chen^1,2,3

Journal of Renewable Materials, Vol.11, No.8, pp. 3351-3370, 2023, DOI:10.32604/jrm.2023.027512

Abstract In order to improve the comprehensive utilization rate of high fines sand (HFS) produced by the mine, full solid waste shotcrete (HFS-BFRS) was prepared with HFS as fine aggregate in cooperation with basalt fiber (BF). The strength growth characteristics of HFS-BFRS were analyzed. And the fitting equation of compressive strength growth characteristics of HFS-BFRS under the synergistic effect of multiple factors was given. And based on the orthogonal experimental method, the effects on the compressive strength, splitting tensile strength and flexural strength of HFS-BFRS under the action of different levels of influencing factors were investigated. The effect of three factors… More >

Yafei Hu^1,2, Keqing Li^1,2, Lujing Zheng³, Bin Han^1,2,*

Journal of Renewable Materials, Vol.11, No.5, pp. 2491-2511, 2023, DOI:10.32604/jrm.2023.025129

Abstract Tailings known as solid waste are generated by the mining industry. The development of tailings as wet shotcrete aggregates has significant economic and environmental benefits. The fine particle size of the tailings results in a large consumption of traditional cement as a cementitious material and insignificant improvement in strength. Therefore, a composite cementitious system of cement and solid waste resources (fly ash and slag powder) is explored for this study. In this paper, the response surface methodology (RSM) is used to optimize the experimental design and a multivariate nonlinear response model with cement, fly ash and slag powder contents as… More >

Jianbing Zhang¹, Rongjin Liu^1,2,3,*, Siyuan Fu¹, Tianyu Gao¹, Zhongfei Zhang¹

Journal of Renewable Materials, Vol.9, No.11, pp. 2001-2013, 2021, DOI:10.32604/jrm.2021.015812

Abstract Based on aluminum sulfate, a fluorine-free and alkali-free liquid accelerator (FF-AF-A) was prepared in this study. The setting time and compressive strength of three cement types with different FF-AF-A dosages were fully investigated. The compatibility of the FF-AF-A with the superplasticizers were also investigated, and the early hydration behavior and morphology of the hydration products of reference cement paste with the FF-AF-A were explored by hydration heat, X-ray diffractometry (XRD), and scanning electron microscopy (SEM). Test results indicated that adding the FF-AF-A at 8 wt% of the cement weight resulted in 2 min 35 s initial setting time and 6… More >

Chang Su^1,2, Qiangqiang Zheng^3,*, Wukun Zhao⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 947-960, 2020, DOI:10.32604/fdmp.2020.09676

Abstract In this research, the dynamics of wet spray nozzles with different geometries, used to accelerate shotcrete, are investigated on the basis of a suitable three-dimensional mathematical model and related numerical method. Simulations have been conducted in the frame of the SIMPLEC algorithm. The k-ε turbulence model has been used to account for turbulent effects. The study shows that when the angle of the convergent section is less than 3°, it has a scarce effect on the dynamics of the jet of shotcrete; with the increase of the convergence angle, the shotcrete jet velocity decreases and the nozzle wear increases; when… More >

S. Ullah¹, B. Pichler¹, S. Scheiner^1,2, C. Hellmich^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.3, pp. 279-316, 2010, DOI:10.3970/cmes.2010.057.279

Abstract Point-wise optical measurements of 3D displacement vectors over time are a key input for monitoring shotcrete tunnel shells during construction according to the New Austrian Tunnelling Method (NATM). Aiming at estimation of the stresses prevailing in the highly loaded, hydrating material, we here deal with two different interpolation strategies for reconstructing, from measured displacement vectors, the 3D displacement field histories of the inner surface of the tunnel shell. The first approach considers spatial interpolation of displacement components in a fixed Cartesian base frame, while the second (new) approach refers to displacement components in a moving base frame consisting of vectors… More >