scholarly journals Pore Structure Evolution and Its Effect on Strength Development of Sulfate-Containing Cemented Paste Backfill

Minerals ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 8 ◽  
Author(s):  
Hao Rong ◽  
Min Zhou ◽  
Haobo Hou
Keyword(s):  
Pore Structure ◽  
Structure Evolution ◽  
Strength Development ◽  
Cemented Paste Backfill ◽  
Paste Backfill

Pore Structure Evolution of Cemented Paste Backfill Observed with Two-Dimensional NMR Relaxation Correlation Measurements

2021 ◽  
Vol 60 (36) ◽  
pp. 13253-13264
Author(s):  
Neil Robinson ◽  
Razyq Nasharuddin ◽  
Ganhua Luo ◽  
Andy Fourie ◽  
Einar O. Fridjonsson ◽  
...  
Keyword(s):  
Pore Structure ◽  
Nmr Relaxation ◽  
Structure Evolution ◽  
Two Dimensional ◽  
Cemented Paste Backfill ◽  
Paste Backfill

scholarly journals Effects of Superplasticizer on the Hydration, Consistency, and Strength Development of Cemented Paste Backfill

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 381 ◽  
Author(s):  
Jian Zhang ◽  
Hongwei Deng ◽  
Abbas Taheri ◽  
Junren Deng ◽  
Bo Ke
Keyword(s):  
Underground Mines ◽  
Strength Development ◽  
Strength Increase ◽  
Strengthening Effect ◽  
Cemented Paste Backfill ◽  
Solid Concentration ◽  
Resonance System ◽  
Low Field ◽  
Binder Ratio ◽  
Paste Backfill

The strength and consistency of cemented paste backfill (CPB) are of key concerns in the stope stability and cost control for underground mines. It is common practice to use additives, such as superplasticizer, to improve the performance of CPB. This study mainly focuses on the effects of superplasticizer on the hydration, consistency, and strength of CPB. In this study, a polynaphtalene sulfonate was used as the superplasticizer. The binder is a mix of 33.3% ordinary Portland cement and 66.7% fly ash. The CPB specimens with a tailings-binder ratio of 3:1 and a solid concentration of 70% were then tested by a low field nuclear magnetic resonance system after different hydration times. Effects of polynaphtalene sulfonate on the hydration, fluidity, and strength were investigated. Results showed that the polynaphtalene sulfonate has a strong influence on short-duration hydration, which may contribute to the strength increase of CPB. It has been demonstrated that the polynaphtalene sulfonate improved the fluidity of the CPB mixture. With the increased dosage of polynaphtalene sulfonate, the slump increased. It was also found that the polynaphtalene sulfonate dosage has a negligible effect on the 1 day (d) strength while it has a strengthening effect on the 7 d, 14 d, and 28 d strength of CPB specimens.

Characterization of cemented paste backfill pore structure using SEM and IA analysis

2008 ◽  
Vol 67 (2) ◽  
pp. 139-152 ◽  
Author(s):  
Serge Ouellet ◽  
Bruno Bussière ◽  
Michel Aubertin ◽  
Mostafa Benzaazoua
Keyword(s):  
Pore Structure ◽  
Cemented Paste Backfill ◽  
Paste Backfill

Pore structure in a gold mine cemented paste backfill

2013 ◽  
Vol 53 ◽  
pp. 144-151 ◽  
Author(s):  
E.O. Fridjonsson ◽  
A. Hasan ◽  
A.B. Fourie ◽  
M.L. Johns
Keyword(s):  
Pore Structure ◽  
Gold Mine ◽  
Cemented Paste Backfill ◽  
Paste Backfill

scholarly journals Strength and Pore Structure Development of High-Plasticity Clay Treated with MK-Blended Cement

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Qian Guo ◽  
Mingli Wei ◽  
Haochen Xue ◽  
Changhui Gao ◽  
Guangyin Du
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Unconfined Compressive Strength ◽  
Structure Refinement ◽  
Structure Evolution ◽  
Strength Development ◽  
High Plasticity ◽  
Soil Mixture ◽  
Treated Soil ◽  
High Plasticity Clay

This paper focuses on the strength development and pore structure evolution of high-plasticity clay mixtures treated with metakaolin- (MK-) blended ordinary Portland cement (OPC). The unconfined compressive strength (fcu) of treated soil mixtures is measured to study the effect of MK replacement. The microstructural study is carried out by mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results showed that the MK replacement led to the decrease of unconfined compressive strength of OPC-treated soil mixture cured for 28 days, but the influence on 7 days strength was negligible. However, the MK addition also enhanced the unconfined compressive strength significantly. The MK addition provided more cementitious products by secondary hydration and pozzolanic reaction, which would give rise to a notable filling effect by turning the large pores (1 to 10 μm) into smaller ones (0.1 to 1 μm). However, the MK replacement led to a decrease of cementitious products due to the lack of calcium hydroxide (CH) in soil mixture, and thus the effect on pore structure refinement was reduced. Nevertheless, the presence of MK enhanced the unconfined compressive strength cured for 7 days, due to the high reactivity of MK with CH.

scholarly journals Mechanical Transformation of Fly Ash toward Its Utilization in Cemented Paste Backfill

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Haijun Wang ◽  
Yun Duan
Keyword(s):  
Fly Ash ◽  
Strength Development ◽  
Sustainable Utilization ◽  
Cemented Paste Backfill ◽  
Efficient Technology ◽  
Pozzolanic Reactivity ◽  
Wet Grinding ◽  
Paste Backfill ◽  
Mechanical Transformation ◽  
Wet Ground

Fly ash (FA) showed low reactivity when being used to prepare the binder for cemented paste backfill (CPB). In the present work, wet-grinding treatment was used to increase the pozzolanic reactivity of FA and promote its sustainable utilization. The results showed that wet-grinding could be a suitable and efficient technology for FA pretreatment. Wet-grinding strongly modified the structure of FA by decreasing the crystalline phase content and the binding energy of Si 2p and Al 2p, contributing to the increase in pozzolanic reactivity of FA. The performance of CPB samples prepared by wet-ground FA was then optimized. This was reflected by the acceleration in the sample setting and increase in the strength development. The compressive strength of the CPB samples prepared by wet-ground FA for 120 min was increased by around 40% after curing for 28 d compared with the control samples.

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