Experimental Study on Direct Tensile Properties of Cemented Paste Backfill

Guo, Lei; Peng, Xiaopeng; Zhao, Yanxiu; Liu, Guangsheng; Tang, Guoxing; Pan, Andrew

doi:10.3389/fmats.2022.864264

Cited by 11 publications

(11 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The difference in the ore's stability and hardness coefficients means there is also a significant difference in the mutual stress effect between the CPB and the ore. Especially for mining fractured ore in a deep high-stress environment, the CPB is susceptible to deformation by the stress transfer of the fractured ore and exhibits noticeable differences in mechanical properties (Guo et al 2022).…”

Section: Introductionmentioning

confidence: 99%

Mechanical properties and mesoscopic analysis of rockbackfill-rock composite sample under dynamic loading

Zheng¹,

Li²,

Liu³

et al. 2023

Paste 2023: 25th International Conference on Paste, Thickened and Filtered Tailings

View full text Add to dashboard Cite

During ore pillar excavation, the impact load of deep hole blasting does not act directly in the cemented paste backfill (CPB), which first acts within the ore pillar and then transfers the blast energy to the CPB and the adjacent ore. Therefore, it is a key issue to investigate the stability of the rock-backfill composite under dynamic loading. The paper prepared rock-backfill-rock (RBR) composite samples and conducted the Split Hopkinson Pressure Bar (SHPB) dynamic test with different impact amplitude. The dynamic uniaxial strength characteristics, mechanical characteristics, and failure modes of RBR composite samples under different impact velocities were analysed. The experimental results showed that the dynamic uniaxial compressive strength of the RBR sample increases first and then decreases with the increase of the average strain rate. With the rise in the average strain rate, the fragmentation degree of the RBR sample is deepened. According to the computerised tomography (CT) test results, the rock fails mainly in shear. Moreover, damage occurs at the interface between the CPB and the rock near the incident bar. It is primarily manifested as a ring-layered crack, resulting in its separation from the rock near the incident bar. The results of the study can further guide the stability of the backfill stope during the ore pillar extraction process.

show abstract

Section: Introductionmentioning

confidence: 99%

Mechanical properties and mesoscopic analysis of rockbackfill-rock composite sample under dynamic loading

Zheng¹,

Li²,

Liu³

et al. 2023

Paste 2023: 25th International Conference on Paste, Thickened and Filtered Tailings

View full text Add to dashboard Cite

show abstract

“…The essential design properties of CTB, such as uniaxial compressive strength (UCS), cohesion and the angle of internal friction, can be accurately obtained by uniaxial and triaxial compression tests respectively (Belem et al 2000;Kesimal et al 2005;Fall et al 2007). Tensile strength is also a critical strength property of CTB, but there has still been insufficient research on its determination (Pan & Grabinsky 2021; Guo et al 2022). Tensile strength affects the quality of CTB in many cases and is further related to the safety of mine production.…”

Section: Introductionmentioning

confidence: 99%

“…Secondly, DTT specimens are relatively complex-shaped and challenging to make (Mellor & Hawkes 1971;Coviello et al 2005;Butenuth et al 1993). Although DTTs are constantly being improved, such as the invention of compression-to-tension load converters (CTLC) and moulds made using 3D printing technology, there are still limitations to the use of DTTs (Pan & Grabinsky 2021;Guo et al 2022).…”

Section: Introductionmentioning

confidence: 99%

Determination of the relationship between direct tensile test and Brazilian splitting test of cemented tailings backfill

Tang¹,

Li²,

Liu³

et al. 2023

Paste 2023: 25th International Conference on Paste, Thickened and Filtered Tailings

View full text Add to dashboard Cite

Cemented tailings backfill (CTB) is an artificial structure that provides ground support for the mining structure in the cut-and-fill mining method. The stability of CTB has a bearing on safe and economical production in mines. Tensile strength is an important design parameter that affects the quality of CTB. The Brazilian splitting test (BT) operation is more convenient but the accuracy of results is insufficient. The direct tensile test (DTT), the results of which are accurate though the test threshold is high, can be used to determine the tensile strength of CTB. Therefore, by determining the differences between the results of the two test methods, the tensile strength of CTB can be obtained more precisely using BT. In this study, DTT and BT were performed on CTB with various solid mass contents, binder contents and curing times. The findings demonstrated that, with only numerical differences, the tensile strength of CTB obtained from DTT and BT follows the same pattern of variation with binder content, solid mass content and curing period. The results of BT were lower than those of DTT because the Poisson effect reduces the tensile strength of the BT specimens. A linear fit between the DTT and BT results showed a strong linear correlation with a scale factor of 2.435. This study obtained the scale relationship between the DTT and BT results for the CTB at the test level. The study's findings can serve as a guide for improving the quality assessments and strength designs of CTB in mines.

show abstract

“…7,8 As one of the most important design criteria, mechanical stability has been commonly adopted to assess the engineering performance of CPB technology. Correspondingly, the uniaxial compressive strength (UCS), 9 tensile strength, 10 and shear strength 11 are often utilized to evaluate the mechanical performance of CPB materials under field loadings. However, owing to the brittle behavior of long-term CPB and poor tensile strength, failure still happens when CPB structures are subjected to mining disturbance even with sufficient UCS and shear strength.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of fiber content and length on curing time‐dependent mode‐I fracture behavior and properties of cemented paste backfill and implication to engineering design

Fang

Cui

2022

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

The inclusion of fiber in cemented paste backfill (CPB) can significantly alter the mechanical response of the CPB body. The intrinsic defects in CPB and the potential dynamic loading condition make it necessary to investigate the fracture properties of fiber-reinforced CPB (FR-CPB). The mode-I fracture behavior and properties are crucial to the successful engineering application of FR-CPB technology used in underground mines. The contribution of fiber length and content to the evolutive mode-I fracture behavior and properties of FR-CPB was examined in this study. The results show that the addition of fiber reduces the prepeak stiffness but improves the mode I fracture toughness (K Ic ), and the improvement in K Ic increases with fiber length. In contrast, the initial increase in fiber content (from 0% to 0.5%) benefits the K Ic acquisition, while a further increase in fiber content from 0.5% to 0.75% poses a negative influence on the K Ic development. Moreover, with the adoption of the cement hydration model, four predictive functions are proposed to describe the contribution of fiber length and content to the development of fracture properties. In addition, K Ic is identified as a more reliable fracture property for assessing the immediate ground support role played by the FR-CPB structure. The findings are helpful when it comes to the determination of the fiber length and content in FR-CPB design. K E Y W O R D Scemented paste backfill, fiber reinforcement, fracture toughness, tailings, underground mine List of abbreviations/symbols: CB, chevron bend; CCNBD, cracked chevron-notched Brazilian disc; FRCC, fiber-reinforced cementitious composites; FR-CPB, fiber-reinforced cemented paste backfill; K IC , mode I fracture toughness; LPD, load-point displacement; NT, natural tailings; PSD, particle size distribution; SCB, semicircular bending test; SR, short rod; ST, silicate tailings; TSF, tailings storage facilities; UCS, uniaxial compressive strength; w /c, water to cement ratio; T, thickness of sample; F l , fiber length; F c , fiber content; F lr , reference fiber length; a, notch length; D, diameter of sample; FM-ITZ, fiber-matrix interfacial transition zone; P, normal force; S, half of the distance between the two supporting rollers; R, radius of sample; k s , stiffness; E i , fracture initiation energy; E m , critical fracture energy; P m , peak force; Y I , stress intensity factor; u, displacement; i, stage number; E p , postpeak fracture energy; ξ f , final degree of cement hydration; ξ, degree of cement hydration; τ, curing time constant; β, shape constant; t e , curing time; T r , reference curing temperature; T c , actual curing temperature; E a , energy activating cement hydration; R', natural gas constant; a i , b i , c i , d i , fitting constants.

show abstract

Experimental Study on Direct Tensile Properties of Cemented Paste Backfill

Cited by 11 publications

References 41 publications

Mechanical properties and mesoscopic analysis of rockbackfill-rock composite sample under dynamic loading

Mechanical properties and mesoscopic analysis of rockbackfill-rock composite sample under dynamic loading

Determination of the relationship between direct tensile test and Brazilian splitting test of cemented tailings backfill

Experimental investigation of fiber content and length on curing time‐dependent mode‐I fracture behavior and properties of cemented paste backfill and implication to engineering design

Contact Info

Product

Resources

About