Initial temperature-dependence of strength development and self-desiccation in cemented paste backfill that contains sodium silicate

2016 ◽  
Vol 67 ◽  
pp. 101-110 ◽  
Author(s):  
Yong Wang ◽  
Mamadou Fall ◽  
Aixiang Wu
Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 381 ◽  
Author(s):  
Jian Zhang ◽  
Hongwei Deng ◽  
Abbas Taheri ◽  
Junren Deng ◽  
Bo Ke

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.


2016 ◽  
Vol 72 ◽  
pp. 10-19 ◽  
Author(s):  
Z. Aldhafeeri ◽  
M. Fall ◽  
M. Pokharel ◽  
Z. Pouramini

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Haijun Wang ◽  
Yun Duan

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Aixiang Wu ◽  
Yong Wang ◽  
Bo Zhou ◽  
Jiahua Shen

Enhancing the knowledge on the deformation behavior of cemented paste backfill (CPB) in terms of stress-strain relations and modulus of elasticity is significant for economic and safety reasons. In this paper, the effect of the initial backfill temperature on the CPB’s stress-strain behavior and modulus of elasticity is investigated. Results show that the stress-strain relationship and the modulus of elasticity behavior of CPB are significantly affected by the curing time and initial temperature of CPB. Additionally, the relationship between the modulus of elasticity and unconfined compressive strength (UCS) and the degree of hydration was evaluated and discussed. The increase of UCS and hydration degree leads to an increase in the modulus of elasticity, which is not significantly affected by the initial temperature.


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