Constitutive modelling of cemented paste backfill: A data-mining approach

Qi, Chongchong; Chen, Qiusong; Fourie, Andy; Tang, Xiaolin; Zhang, Qinli; Dong, Xiangjian; Yan, Feng

doi:10.1016/j.conbuildmat.2018.11.142

Cited by 72 publications

(30 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a widely used detection mean of the mechanical properties of CPB for exploring an efficient mix design and reaching a higher performance in underground mining structures [43], the standard UCS tests were carried out in this study. For each ratio, there were three corresponding specimens.…”

Section: Test Of Uniaxial Compressive Strength (Ucs)mentioning

confidence: 99%

Utilisation of Water-Washing Pre-Treated Phosphogypsum for Cemented Paste Backfill

et al. 2019

Self Cite

View full text Add to dashboard Cite

Recycling phosphogypsum (PG) for cemented paste backfill (CPB) has been widely used at phosphate mines in China. However, the impurities in PG prolong the setting time and reduce the uniaxial compressive strength (UCS), limiting the engineering application of PG. This paper aims to investigate the feasibility of treated PG (TPG) washed repeatedly using deionised water (DW) for CPB. A water-washing pre-experiment was first conducted to find the proportion with the least DW demand and the effects of water-washing on ordinary PG (OPG). Then, based on the PG:DW ratio obtained from the pre-experiment, the properties of the OPG-based CPB (OCPB) and TPG-based CPB (TCPB) were tested using slump tests, UCS tests, and microstructural analysis. The results show that (1) after 11 water-washings at the PG:DW ratio of 1:1.75, the pH of the supernatant (pH = 6.328) meets the requirements of Chinese standard GB 8978-1996. (2) Water-washing improves the particle gradation quality of PG and removes the soluble impurities adsorbed at the surface of PG crystals. (3) The initial slump values of TCPB are 0.19–1.15 cm higher than that of OCPB, furthermore, the diffusivity values of TCPB are better than the performance of OCPB, with 0.61–1.68 cm of superiority. (4) The UCS values of TCPB are up to 0.838 MPa, 1.953 MPa, and 2.531 MPa, after curing for 7, 14, and 28 days. These are 0.283 MPa, 0.823 MPa, and 0.881 MPa higher than that of OCPB, respectively. It can be concluded that water-washing pre-treatment greatly improves the workability and mechanical property of PG-based CPB. These results are of great value for creating a reliable and environmentally superior alternative for the recycling of PG and for safer mining production.

show abstract

Section: Test Of Uniaxial Compressive Strength (Ucs)mentioning

confidence: 99%

Utilisation of Water-Washing Pre-Treated Phosphogypsum for Cemented Paste Backfill

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…CPB is a composite material produced with dewatered mine tailings (70-85% solids by weight), hydraulic binders (3-7% by dry paste weight) and water [13][14][15]. For the successful application of CPB, the hydration of cement needs to be investigated.…”

Section: Introductionmentioning

confidence: 99%

Understanding Cement Hydration of Cemented Paste Backfill: DFT Study of Water Adsorption on Tricalcium Silicate (111) Surface

Liü

et al. 2019

Minerals

Self Cite

View full text Add to dashboard Cite

Understanding cement hydration is of crucial importance for the application of cementitious materials, including cemented paste backfill. In this work, the adsorption of a single water molecule on an M3-C 3 S (111) surface is investigated using density functional theory (DFT) calculations. The adsorption energies for 14 starting geometries are calculated and the electronic properties of the reaction are analysed. Two adsorption mechanisms, molecular adsorption and dissociative adsorption, are observed and six adsorption configurations are found. The results indicate that spontaneous dissociative adsorption is energetically favored over molecular adsorption. Electrons are transferred from the surface to the water molecule during adsorption. The density of states (DOS) reveals the bonding mechanisms between water and the surface. This study provides an insight into the adsorption mechanism at an atomic level, and can significantly promote the understanding of cement hydration within such systems.

show abstract

“…This process may result in the formation of protein-surfactant (SDS-SPI) complex chemicals. In addition, loose connections between domains are compromised, resulting in a decrease in the molecular weight of the protein, which can be enhanced if it occurs within a certain range [76][77][78][79][80][81][82]. At the same time, comparing the results before and after the modification, it was found that the modified SDS-SPI moved to the left at the absorption peaks of 3377.33 cm −1 , 2800 cm −1 and 1393.1 cm −1 during the strengthening process.…”

Section: Infrared Spectra Testsmentioning

confidence: 99%

Development of Environmental Friendly Dust Suppressant Based on the Modification of Soybean Protein Isolate

Nie

Zhang

et al. 2019

Processes

View full text Add to dashboard Cite

Aiming to further improve the dust suppression performance of the dust suppressant, the present study independently develops a new type of biodegradable environmentally-friendly dust suppressant. Specifically, the naturally occurring biodegradable soybean protein isolate (SPI) is selected as the main material, which is subject to an anionic surfactant, i.e., sodium dodecyl sulfonate (SDS) for modification with the presence of additives including carboxymethylcellulose sodium and methanesiliconic acid sodium. As a result, the SDS-SPI cementing dust suppressant is produced. The present study experimentally tests solutions with eight different dust suppressant concentrations under the same experimental condition, so as to evaluate their dust suppression performances. Key metrics considered include water retention capability, cementing power and dust suppression efficiency. The optimal concentration of dust suppressant solution is determined by collectively comparing these metrics. The experiments indicate that the optimal dust suppressant concentration is 3%, at which level the newly developed environmentally-friendly dust suppressant solution exhibits a decent dust suppression characteristic, with the water retention power reaching its peak level, and the corresponding viscosity being 12.96 mPa·s. This performance can generally meet the requirements imposed by coal mines. The peak efficiency of dust suppression can reach 92.13%. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to analyze the dust suppression mechanism of the developed dust suppressant. It was observed that a dense hardened shell formed on the surface of the pulverized coal particles sprayed with the dust suppressant. There is strong cementation between coal dust particles, and the cementation effect is better. This can effectively inhibit the re-entrainment of coal dust and reduce environmental pollution.

show abstract

Constitutive modelling of cemented paste backfill: A data-mining approach

Cited by 72 publications

References 39 publications

Utilisation of Water-Washing Pre-Treated Phosphogypsum for Cemented Paste Backfill

Utilisation of Water-Washing Pre-Treated Phosphogypsum for Cemented Paste Backfill

Understanding Cement Hydration of Cemented Paste Backfill: DFT Study of Water Adsorption on Tricalcium Silicate (111) Surface

Development of Environmental Friendly Dust Suppressant Based on the Modification of Soybean Protein Isolate

Contact Info

Product

Resources

About