Acceder

Bibliografías temáticas / Cemented paste backfills / Artículos de revistas

Siga este enlace para ver otros tipos de publicaciones sobre el tema: Cemented paste backfills.

Artículos de revistas sobre el tema "Cemented paste backfills"

Autor: Grafiati

Publicado: 4 de junio de 2021

Última modificación: 4 de febrero de 2022

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros

Elija tipo de fuente:

Consulte los 50 mejores artículos de revistas para su investigación sobre el tema "Cemented paste backfills".

Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.

También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.

Explore artículos de revistas sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.

1

Niroshan, Naguleswaran, Nagaratnam Sivakugan y Ryan Llewellyn Veenstra. "Laboratory Study on Strength Development in Cemented Paste Backfills". Journal of Materials in Civil Engineering 29, n.º 7 (julio de 2017): 04017027. http://dx.doi.org/10.1061/(asce)mt.1943-5533.0001848.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Zhang, Xinguo, Jinhai Zhao, Lin Xin, Kun Wang y Haiyang Pan. "Monitoring and Assessment of Cemented Paste Backfill Containing Coal Gangue and Fly Ash in an Underground Mine". Advances in Materials Science and Engineering 2021 (23 de febrero de 2021): 1–15. http://dx.doi.org/10.1155/2021/5946148.

Texto completo

Resumen

Cemented coal gangue paste backfill (CCGPB) containing coal gangue and fly ash is a backfilling technique newly developed in coal mines in China that allows environmentally hazardous products, such as gangue and fly ash, to be reused in underground stopes. CCGPB materials provide efficient ground support for the caving of strata and reduce surface subsidence. In this paper, field monitoring of CCGPB properties was conducted in an underground coal mine, which mainly included the measurement of the longwall face temperature, humidity, CCGPB internal hydration temperature, stress conditions inside the backfills, and displacement. First, the components of the backfills, paste technique, slurry generation procedures, coalfield geology, and mining conditions were introduced. Then, a monitoring system was designed in the field. An online monitoring system was installed. The results of the field monitoring showed that the curing temperature significantly varied, i.e., from 26°C near the main gate to 37°C near the tailgate. The curing humidity had the same trends, increasing from 60% relative humidity (RH) near the main gate to 81% RH near the tailgate. The internal hydration process of the paste was divided into four stages, i.e., the rapid hydration stage, slower hydration stage, rapid decline hydration stage, and relatively stable stage. The highest hydration temperature was 50°C, which was measured on the second day after the backfill process. The temperature approached stability at 41°C. The evolution of the roof stress applied on the CCGPB was divided into four stages: the development stage, regulation stage, rapid growth stage, and relatively stable stage. The maximum roof loading was 12 MPa in the middle of the longwall face. The deformation of the backfill experienced four stages, i.e., the rapid deformation stage, slow deformation stage, relatively stable stage, and long-term stable stage. The maximum deformation was 104.3 mm, appearing in the middle of the face. In addition, the compression ratio of the backfill was approximately 4%. The results of this study showed that the working conditions of backfills in the field were different from those in the laboratory. This paper provides guidance for the design of the CCGPB technique and the predictions of surface subsidence induced by the production process of underground mining.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Ouattara, Drissa, Ammar Yahia, Mamert Mbonimpa y Tikou Belem. "Effects of superplasticizer on rheological properties of cemented paste backfills". International Journal of Mineral Processing 161 (abril de 2017): 28–40. http://dx.doi.org/10.1016/j.minpro.2017.02.003.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Yilmaz, Erol, Tikou Belem y Mostafa Benzaazoua. "Study of physico-chemical and mechanical characteristics of consolidated and unconsolidated cemented paste backfills". Gospodarka Surowcami Mineralnymi - Mineral Resources Management 29, n.º 1 (1 de marzo de 2013): 81–100. http://dx.doi.org/10.2478/gospo-2013-0006.

Texto completo

Resumen

Streszczenie W ostatnich latach obserwuje się, że wydajność i jakość próbek zawiesin nasyconych cementem (CPB - Cement Paste Backfill) in situ są stale niższe niż tych samych próbek przygotowanych w plastikowych formach w laboratorium. Może to wynikać z braku w laboratorium skutecznego narzędzia mogącego naśladować zawiesiny in situ, warunki ich utwardzania jak również rozmiary i geometrię próbek. W celu wypełnienia tej luki, w laboratorium opracowano nowe narzędzie o nazwie CUAPS (Curing Under Applied Pressure System), wytworzone i wykorzystane do zbadania wpływu ciśnienia na podstawie skutecznego nacisku na właściwości fizykochemiczne i mechaniczne CPB, jak również próbek otrzymanych z plastikowych form. Badania porównawcze przeprowadzono zarówno dla próbek CUAPS jak i próbek otrzymanych w laboratorium, zawierających lepiszcza (cementu) 3,45 i 7% wag. po 7, 14 i 28 dniach utwardzania. Wyniki wskazują, że wydajność próbek konsolidowanych CUAPS są zawsze bardziej prawdziwe (realistyczne) niż próbek otrzymanych w laboratorium, głównie z powodu odprowadzania wody w wyniku konsolidacji. Ostatecznie metoda CUAPS powoduje korzystny wpływ na utwardzenie CPB dzięki zawartości wody (separacja wody od świeżej zawiesiny odpadów z cementu) i połączeniu części wody zasobowej z zawiesiną w zrobach.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Coussy, Samuel, Dogan Paktunc, Jérôme Rose y Mostafa Benzaazoua. "Arsenic speciation in cemented paste backfills and synthetic calcium–silicate–hydrates". Minerals Engineering 39 (diciembre de 2012): 51–61. http://dx.doi.org/10.1016/j.mineng.2012.05.016.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Fall, Mamadou y Mukesh Pokharel. "Coupled effects of sulphate and temperature on the strength development of cemented tailings backfills: Portland cement-paste backfill". Cement and Concrete Composites 32, n.º 10 (noviembre de 2010): 819–28. http://dx.doi.org/10.1016/j.cemconcomp.2010.08.002.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Zhao, Yue, Amin Soltani, Abbas Taheri, Murat Karakus y An Deng. "Application of Slag–Cement and Fly Ash for Strength Development in Cemented Paste Backfills". Minerals 9, n.º 1 (30 de diciembre de 2018): 22. http://dx.doi.org/10.3390/min9010022.

Texto completo

Resumen

The present study investigates the combined capacity of a newly developed slag-blended cement (MC) and fly ash (FA) as a sustainable solution towards improving the mechanical performance of the cemented paste backfill (CPB) system of a copper-gold underground mine. A total of thirteen mix designs consisting of three MC-treated and ten MC + FA-treated blends were examined. Samples were prepared with a solids content of 77% (by total mass), and were allowed to cure for 7, 14, 28, 56 and 128 days prior unconfined compression testing. Scanning electron microscopy (SEM) studies were also carried out to observe the evolution of fabric in response to MC and MC + FA amendments. The greater the MC content and/or the longer the curing period, the higher the developed strength, toughness and stiffness. The exhibited improvements, however, were only notable up to 56 days of curing, beyond of which the effect of curing was marginal. The performance of 4% Portland cement or PC (by total dry mass) was found to be similar to that of 1.5% MC, while the higher MC inclusions of 2.5% and 3%, though lower in terms of binder content, unanimously outperformed 4% PC. The use of FA alongside MC improved the bonding/connection interface generated between the tailings aggregates, and thus led to improved mechanical performance compared with similar MC inclusions containing no FA. Common strength criteria for CPBs were considered to assess the applicability of the newly introduced MC and MC + FA mix designs. The mix designs “3% MC” and “2.5% MC + 2–2.5% FA” satisfied the 700 kPa strength threshold required for stope stability, and thus were deemed as optimum design choices.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Yilmaz, Erol. "Stope depth effect on field behaviour and performance of cemented paste backfills". International Journal of Mining, Reclamation and Environment 32, n.º 4 (7 de febrero de 2017): 273–96. http://dx.doi.org/10.1080/17480930.2017.1285858.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Coussy, Samuel, Mostafa Benzaazoua, Denise Blanc, Pierre Moszkowicz y Bruno Bussière. "Arsenic stability in arsenopyrite-rich cemented paste backfills: A leaching test-based assessment". Journal of Hazardous Materials 185, n.º 2-3 (enero de 2011): 1467–76. http://dx.doi.org/10.1016/j.jhazmat.2010.10.070.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Zhao, Taheri, Soltani, Karakus y Deng. "Strength Development and Strain Localization Behavior of Cemented Paste Backfills Using Portland Cement and Fly Ash". Materials 12, n.º 20 (9 de octubre de 2019): 3282. http://dx.doi.org/10.3390/ma12203282.

Texto completo

Resumen

This study examines the combined performance of Portland cement (PC), the binder, and fly ash (FA), the additive, towards improving the mechanical performance of the South Australian copper-gold underground mine cemented paste backfill (CPB) system. A series of unconfined compressive strength (UCS) tests were carried out on various mix designs to evaluate the effects of binder and/or additive contents, as well as curing time, on the CPB’s strength, stiffness and toughness. Moreover, the failure patterns of the tested samples were investigated by means of the three-dimensional digital image correlation (DIC) technique. Making use of several virtual extensometers, the state of axial and lateral strain localization was also investigated in the pre- and post-peak regimes. The greater the PC content and/or the longer the curing period, the higher the developed strength, stiffness and toughness. The use of FA alongside PC led to further strength and stiffness improvements by way of inducing secondary pozzolanic reactions. Common strength criteria for CPBs were considered to assess the applicability of the tested mix designs; with regards to stope stability, 4% PC + 3% FA was found to satisfy the minimum 700 kPa threshold, and thus was deemed as the optimum choice. As opposed to external measurement devices, the DIC technique was found to provide strain measurements free from bedding errors. The developed field of axial and lateral strains indicated that strain localization initiates in the pre-peak regime at around 80% of the UCS. The greater the PC (or PC + FA) content, and more importantly the longer the curing period, the closer the axial stress level required to initiate localization to the UCS, thus emulating the failure mechanism of quasi-brittle materials such as rock and concrete. Finally, with an increase in curing time, the difference between strain values at the localized and non-localized zones became less significant in the pre-peak regime and more pronounced in the post-peak regime.

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Ouattara, Drissa, Tikou Belem, Mamert Mbonimpa y Ammar Yahia. "Effect of superplasticizers on the consistency and unconfined compressive strength of cemented paste backfills". Construction and Building Materials 181 (agosto de 2018): 59–72. http://dx.doi.org/10.1016/j.conbuildmat.2018.05.288.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Yilmaz, Erol, Tikou Belem, Bruno Bussière y Mostafa Benzaazoua. "Relationships between microstructural properties and compressive strength of consolidated and unconsolidated cemented paste backfills". Cement and Concrete Composites 33, n.º 6 (julio de 2011): 702–15. http://dx.doi.org/10.1016/j.cemconcomp.2011.03.013.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Yilmaz, Erol, Tikou Belem y Mostafa Benzaazoua. "Specimen size effect on strength behavior of cemented paste backfills subjected to different placement conditions". Engineering Geology 185 (febrero de 2015): 52–62. http://dx.doi.org/10.1016/j.enggeo.2014.11.015.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Qi, Chongchong, Qiusong Chen, Xiangjian Dong, Qinli Zhang y Zaher Mundher Yaseen. "Pressure drops of fresh cemented paste backfills through coupled test loop experiments and machine learning techniques". Powder Technology 361 (febrero de 2020): 748–58. http://dx.doi.org/10.1016/j.powtec.2019.11.046.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Chen, Xin, Xiuzhi Shi, Shu Zhang, Hui Chen, Jian Zhou, Zhi Yu y Peisheng Huang. "Fiber-Reinforced Cemented Paste Backfill: The Effect of Fiber on Strength Properties and Estimation of Strength Using Nonlinear Models". Materials 13, n.º 3 (5 de febrero de 2020): 718. http://dx.doi.org/10.3390/ma13030718.

Texto completo

Resumen

This experimental investigation was conducted to research the properties of polypropylene (PP) fiber-reinforced cemented paste backfill (CPB). The unconfined compressive strength (UCS) of the fiber-reinforced CPB showed a significant improvement with average UCS increase ratios of 141.07%, 57.62% and 63.17% at 3, 7 and 28 days, respectively. The macroscopic failure mode and SEM analysis indicated that fibers prevented the formation of large tensile and shear cracks during the pull-out and pull-off failure modes. A linear fitting function for the UCS at a curing time of 3 days and two polynomial fitting functions for the UCS at curing times of 7 and 28 days were established to characterize the relationship between the UCS of the fiber-reinforced and unreinforced CPB. Moreover, based on composite mechanics, nonlinear models related to the UCS and fiber reinforcement index were obtained. The estimated functions containing the fiber reinforcement index λ, which consists of the fiber content and aspect ratio of fiber, could evaluate the UCS. Furthermore, the fiber reinforcement index λ quantifies the enhancement by the fibers. Both estimation results indicated that the UCS values were estimated accurately at curing times of 3, 7 and 28 days in this study. Additionally, the estimation models could be used to guide the strength design of fiber-reinforced CPB. Besides this, the results showed that fiber-reinforced CPB can be used more widely in mine backfills and meets the requirements of controlled low-strength material (CLSM) for broader applications.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Wang, Yu, Changhong Li, Zhiqiang Hou, Xuefeng Yi y Xiaoming Wei. "In Vivo X-ray Computed Tomography Investigations of Crack Damage Evolution of Cemented Waste Rock Backfills (CWRB) under Uniaxial Deformation". Minerals 8, n.º 11 (21 de noviembre de 2018): 539. http://dx.doi.org/10.3390/min8110539.

Texto completo

Resumen

Cemented waste rock backfill (CWRB), which is a mixture of tailings, waste rock, cement, and water, is subjected to combination actions in underground mining operations and has been widely used in deep resource mining. While the strength requirement and macroscopic deformation behaviors of CWRB have been well studied, the mesoscopic damage evolution mechanisms are still not well understood. In this work, a CWRB sample with a waste rock proportion of 30% was studied with a uniaxial compression test under tomographic monitoring, using a 450 kV industrial X-ray computed tomography (CT). Clear CT images, CT value analysis, crack identification, and extraction reveal that CWRB damage evolution is extremely inhomogeneous and affected by the waste rock size, shape, and distribution. Furthermore, the crack initiation, propagation, and coalescence behaviors are limited to the existing waste rocks. When deformation grows to a certain extent, the cracks demonstrate an interlocking phenomenon and their propagation paths are affected by the waste rocks, which may improve the ability to resist compressive deformation. Volumetric dilatancy caused by the damage and cracking behavior has closed a link with the meso-structural changes, which are controlled by the interactions between the waste rocks and the cemented tailing paste.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Mbonimpa, Mamert, Parrein Kwizera y Tikou Belem. "Mine Backfilling in the Permafrost, Part II: Effect of Declining Curing Temperature on the Short-Term Unconfined Compressive Strength of Cemented Paste Backfills". Minerals 9, n.º 3 (11 de marzo de 2019): 172. http://dx.doi.org/10.3390/min9030172.

Texto completo

Resumen

When cemented paste backfill (CPB) is used to fill underground stopes opened in permafrost, depending on the distance from the permafrost wall, the curing temperature within the CPB matrix decreases progressively over time until equilibrium with the permafrost is reached (after several years). In this study, the influence of declining curing temperature (above freezing temperature) on the evolution of the unconfined compressive strength (UCS) of CPB over 28 days’ curing is investigated. CPB mixtures were prepared with a high early (HE) cement and a blend of 80% slag and 20% General Use cement (S-GU) at 5% and 3% contents and cured at room temperature in a humidity chamber and under decreasing temperatures in a temperature-controlled chamber. Results indicate that UCS is higher for CPB cured at room temperature than under declining temperatures. UCS increases progressively from the stope wall toward the inside of the CPB mass. Under declines in curing temperature, HE cement provides better short-term compressive strength than does S-GU binder. In addition, the gradual decline in temperature does not appear to affect the fact that the higher the binder proportion, the greater the strength development. Therefore, UCS is higher for samples prepared with 5% than 3% HE cement. Findings are discussed in terms of practical applications.

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Jiang, Haiqiang, Zhaojun Qi, Erol Yilmaz, Jing Han, Jingping Qiu y Chunlei Dong. "Effectiveness of alkali-activated slag as alternative binder on workability and early age compressive strength of cemented paste backfills". Construction and Building Materials 218 (septiembre de 2019): 689–700. http://dx.doi.org/10.1016/j.conbuildmat.2019.05.162.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Orejarena, Libardo y Mamadou Fall. "Artificial neural network based modeling of the coupled effect of sulphate and temperature on the strength of cemented paste backfill". Canadian Journal of Civil Engineering 38, n.º 1 (enero de 2011): 100–109. http://dx.doi.org/10.1139/l10-109.

Texto completo

Resumen

Among the different options for mine waste management, cemented paste backfills (CPB) have become important in mining operations around the world due to their environmental and economic benefits. The key design parameter of a CPB structure is its mechanical stability, which is commonly evaluated by the uniaxial compressive strength (UCS) of the CPB material. Experimental studies have shown that the sulphate present within the CPB and the curing temperatures can significantly affect the strength of CPBs. The increasing use of CPBs in underground mine operations as well as the subjection of CPBs to a large variability of thermal (curing temperature) and chemical (sulphate content) loads, make it necessary to model and quantify the coupled effect of sulphate and curing temperature on the strength (key design parameter) of CPBs. Therefore, the main objective of this study is to develop a methodological approach and a mathematical model based on an artificial neural network (ANN) to analyze and predict the effect of different amounts of sulphate on the strength of mature CPBs cured at various temperatures. Based on the experimental results of UCS tests from previous studies on various CPBs, the authors have developed an ANN model by using an ANN methodology implemented through MATLAB™. The developed model is validated with experimental data that is not used for the model development. The validation shows good agreement between the predicted and experimental data. The results from the ANN model of this study show that the coupled effect of curing temperature and sulphate significantly affects the strength of CPBs. This effect can be positive (strength increase) or negative (strength decrease) depending on the initial amount of sulphate content, the curing temperature, and type of binder. Furthermore, this study demonstrates that ANN can be used as a valuable tool to evaluate the coupled influence of sulphate and temperature on the strength of CPBs, i.e., it is a suitable tool for the optimization of a CPB mixture.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Klein, Katherine y Dragana Simon. "Effect of specimen composition on the strength development in cemented paste backfill". Canadian Geotechnical Journal 43, n.º 3 (1 de marzo de 2006): 310–24. http://dx.doi.org/10.1139/t06-005.

Texto completo

Resumen

This paper focuses on monitoring setting and strength development in cemented paste backfill (CPB). The composition of the paste is altered to study the effects of binder type and content, selected chemical admixtures (superplasticizers), mineral additives (e.g., fly ash), and pore fluid chemistry (e.g., ionic concentration and pH) on these properties. The three main techniques utilized are shear wave velocity measurements, penetration tests (e.g., Vicat needle tests), and unconfined compressive strength tests. All of these tests are sensitive to changes in the paste composition. The effect of the pore fluid chemistry and the chemical additives on the CPB properties depends on the ion type and concentration and the chemical composition of the superplasticizers. The shear wave velocity in both uncemented and cemented pastes increases with time as a result of self-weight consolidation, capillary forces, and cementation (the precipitation of ions in uncemented tailings pastes or cement hydration in cemented tailings pastes).Key words: cemented paste backfill, shear wave velocity, setting, unconfined compressive strength.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Koupouli, Nabassé J. F., Tikou Belem, Patrice Rivard y Hervé Effenguet. "Direct shear tests on cemented paste backfill–rock wall and cemented paste backfill–backfill interfaces". Journal of Rock Mechanics and Geotechnical Engineering 8, n.º 4 (agosto de 2016): 472–79. http://dx.doi.org/10.1016/j.jrmge.2016.02.001.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Cheng, Qiangqiang, Yaben Guo, Chaowei Dong, Jianfei Xu, Wanan Lai y Bin Du. "Mechanical Properties of Clay Based Cemented Paste Backfill for Coal Recovery from Deep Mines". Energies 14, n.º 18 (13 de septiembre de 2021): 5764. http://dx.doi.org/10.3390/en14185764.

Texto completo

Resumen

Fly ash cement is used to solidify marine clay to prepare marine-clay-based cemented paste backfill (MCCPB) to fill the underground goaf of mines, which not only utilizes solid waste such as fly ash and marine clay, but also controls surface subsidence and protects the environment. To simulate the complex underground mine water environment of the filling body, a dry-wet cycle aquatic environment test under different material ratios and curing ages was designed. The water absorption and unconfined compression strength (UCS) of MCCPB with curing ages of 7 and 28 days under the action of 0, 1, 3, and 7 dry-wet cycles were investigated. The results indicate as the number of dry-wet cycles increases, the surface of MCCPB becomes significantly rougher, and the water content and the solid mass decrease accordingly. Different ratios and curing ages of MCCPB in dry-wet cycles of the UCS tend first to increase, then decrease. Meanwhile, the stress-strain curve of the specimen shows that the trend in the elastic modulus is consistent with that of UCS (first increasing, then decreasing), and that, the minimum UCS value of the specimen still meets the early strength requirements of cemented paste backfill in coal mine geothermal utilization. On the one hand, it proves the feasibility of fly ash cement-solidified marine clay for use as cemented paste backfill in coal mines; on the other hand, it also expands the available range of cemented paste backfill materials in coal mines.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Klein, K. y D. Simon. "Electromagnetic Properties of Cemented Paste Backfill". Journal of Environmental & Engineering Geophysics 11, n.º 1 (1 de marzo de 2006): 27–41. http://dx.doi.org/10.2113/jeeg11.1.27.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Niroshan, Naguleswaran, Nagaratnam Sivakugan y Ryan Llewellyn Veenstra. "Flow Characteristics of Cemented Paste Backfill". Geotechnical and Geological Engineering 36, n.º 4 (17 de enero de 2018): 2261–72. http://dx.doi.org/10.1007/s10706-018-0460-8.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Pan, Andrew N. y Murray W. F. Grabinsky. "Tensile Strength of Cemented Paste Backfill". Geotechnical Testing Journal 44, n.º 6 (15 de abril de 2021): 20200206. http://dx.doi.org/10.1520/gtj20200206.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Cheng, Kangli, Bingbing Tu, Lang Liu, Bo Zhang y Huafu Qiu. "Damage Strengthening Constitutive Model of Cemented Paste Backfill". Advances in Civil Engineering 2021 (30 de abril de 2021): 1–10. http://dx.doi.org/10.1155/2021/5593983.

Texto completo

Resumen

In order to consider the influence of mesoscopic characteristics of materials on the constitutive model of cemented paste backfill (CPB), the uniaxial compression variables and the damage constitutive model, considering the influence of porosity and pore size of filling materials, were derived based on the strain equivalence principle and Weibull probability distribution function. The nuclear magnetic resonance (NMR) tests and unconfined compression strength (UCS) tests were carried out on 8 groups of CPB specimens with different slurry concentrations and cement-tailings ratios. Then, the expression of damage strengthening coefficient is determined, and the stress-strain curves measured by the theoretical model were compared with the experimental ones. The results show that the uniaxial compression constitutive model proposed is in good agreement with UCS test results and can effectively describe the damage evolution law and the development process of stress-strain curve of CPB under uniaxial compression. The 28-day compressive strength of CPB can reach 8 MPa, the residual strength is about 1∼2 MPa, the elastic modulus is about 200∼2000 MPa, and the porosity is about 3∼5%. The CPB with slurry concentration of 74% and 76% and cement-tailings ratio of 1 : 4 and 1 : 6 is more reasonable, and the relevant mechanical parameters are more stable.

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Fall, M., D. Adrien, J. C. Célestin, M. Pokharel y M. Touré. "Saturated hydraulic conductivity of cemented paste backfill". Minerals Engineering 22, n.º 15 (diciembre de 2009): 1307–17. http://dx.doi.org/10.1016/j.mineng.2009.08.002.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Suazo, Gonzalo, Andy Fourie y James Doherty. "Cyclic Shear Response of Cemented Paste Backfill". Journal of Geotechnical and Geoenvironmental Engineering 143, n.º 1 (enero de 2017): 04016082. http://dx.doi.org/10.1061/(asce)gt.1943-5606.0001581.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Walske, Megan L. y James Doherty. "Incorporating chemical shrinkage volume into Gibson’s solution". Canadian Geotechnical Journal 55, n.º 6 (junio de 2018): 903–8. http://dx.doi.org/10.1139/cgj-2017-0028.

Texto completo

Resumen

Rapid filling of low-permeability cemented paste backfill (CPB) into underground stopes results in the generation of significant excess pore pressures. These are dissipated through conventional consolidation and shrinkage due to cement hydration. Gibson’s solution for excess pore pressures in an accreting sediment can be used to assess the self-weight consolidation of CPB in a stope. In this paper, numerical modelling is used to determine the chemical shrinkage–induced pore pressure response for hydration of CPB for an accreting material and the results presented in a series of dimensionless design charts. It is shown that superposition can be used to combine Gibson’s solution with the newly developed charts for chemical shrinkage–induced pore pressures. This allows a qualitative assessment of potential pore pressure development in a CPB backfilled stope.

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Xu, Wenyuan, Xiaocong Yang, Wenchen Li y Lijie Guo. "Fineness Effect on Pozzolanic Activity of Cu-Ni Slag in Cemented Tailing Backfill". Advances in Materials Science and Engineering 2020 (10 de julio de 2020): 1–7. http://dx.doi.org/10.1155/2020/7172890.

Texto completo

Resumen

This paper presents the experimental results of the fineness effect on the pozzolanic activity of Cu-Ni slag in cemented tailing backfill. Cement paste and cemented tailing backfill samples that without or contain Cu-Ni slag with various grinding times were made and cured at 20°C for 7, 28, and 150 days. Mechanical test and microstructural analyses are performed. In general, the pozzolanic activity of Cu-Ni slag increases with the fineness of particle size. The strength of cemented tailing backfill samples decreased with the addition of Cu-Ni slag. It was found that the pozzolanic activity of Cu-Ni slag used in this study is relatively low. According to the fineness, the Cu-Ni slag will make the cemented tailing backfill samples looser or denser. For the sample containing ground Cu-Ni slag ground for 30 min to 50 min, the sample becomes dense gradually as the particle size of Cu-Ni slag becomes finer.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Wu, D., M. Fall y S. J. Cai. "Coupling temperature, cement hydration and rheological behaviour of fresh cemented paste backfill". Minerals Engineering 42 (marzo de 2013): 76–87. http://dx.doi.org/10.1016/j.mineng.2012.11.011.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Xu, Xiaochuan, Xiaogang Sun, Wei Yao, Pinqi Wu, Jingping Qiu, Zhenbang Guo y Na Liu. "Strength and Ultrasonic Characteristics of Cemented Paste Backfill Incorporating Foaming Agent". Minerals 11, n.º 7 (25 de junio de 2021): 681. http://dx.doi.org/10.3390/min11070681.

Texto completo

Resumen

This work is a systematic study of the strength and ultrasonic properties of cemented paste backfill incorporating a foaming agent, known as foam-cemented paste backfill (FCPB). Based on determining the optimal admixture contents (foaming stabilizer, thickening agent, and foaming agent), a series of uniaxial compressive strength (UCS) tests were conducted to determine the relationship between the UCS of FCPB and four influencing factors, i.e., cement–tailings ratio (CTR), solid content (SC), curing time (T), and foaming agent content (FC). To analyze the sensitivity of UCS to these four factors, grey relational analysis (GRA) was introduced. Moreover, UCS results were correlated with the corresponding ultrasonic pulse velocity (UPV) parameters. The results indicate that the optimal contents of foaming stabilizer, thickening agent and foaming agent are 0.5%, 0.6%, and 1–3%, respectively. The UCS of FCPB exponentially increases with CTR and SC, while it logarithmically and linearly increases with T and FC, respectively. CTR has the most significant influence, followed by T, SC, and FC. There exists an evidently linear relationship between UPV and UCS of FCPB regardless of CTR, SC, T and FC. These results contribute to understanding the properties of hardened FCPB and to sound designs in practice.

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Qiu, Jingping, Yingliang Zhao, Hui Long, Zhenbang Guo, Jun Xing y Xiaogang Sun. "Low-Carbon Binder for Cemented Paste Backfill: Flowability, Strength and Leaching Characteristics". Minerals 9, n.º 11 (15 de noviembre de 2019): 707. http://dx.doi.org/10.3390/min9110707.

Texto completo

Resumen

Blast furnace slag was used as the main raw material to prepare the alkali activated slag (AAS), a low-carbon binder, for cemented paste backfill (CPB). The optimum parameters for preparing the AAS binders using an orthogonal experiment were obtained. Under the optimum conditions (NaOH content was 3 wt. %, Ordinary Portland cement (OPC) content was 7 wt. %, and gypsum dosage was 4 wt. %), the 28 days compressive strength of the binder was 29.55 MPa. The flow ability of the fresh CPB slurry decreased with solid content due to the increased yield stress, while the flow ability increased when rising the binder dosage. A predictive model for the compressive strength of CPB samples was reached through multivariate analysis and the R2 values were higher than 0.9. Sensitivity analysis showed that the solid content is the most important parameter which influences on the development of the CPB strength with a correlation coefficient of 0.826. From the Toxicity Characteristic Leaching Procedure (TCLP) tests, the leaching concentrations of Pb and Cd were below the threshold. As a result, the AAS has potential application as an alternative binder and cemented paste backfill.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Pengyu, Yang y Li Li. "Investigation of the short-term stress distribution in stopes and drifts backfilled with cemented paste backfill". International Journal of Mining Science and Technology 25, n.º 5 (septiembre de 2015): 721–28. http://dx.doi.org/10.1016/j.ijmst.2015.07.004.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Ercikdi, Bayram, Tekin Yılmaz y Gökhan Külekci. "Strength and ultrasonic properties of cemented paste backfill". Ultrasonics 54, n.º 1 (enero de 2014): 195–204. http://dx.doi.org/10.1016/j.ultras.2013.04.013.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Simon, Dragana y Murray Grabinsky. "Apparent yield stress measurement in cemented paste backfill". International Journal of Mining, Reclamation and Environment 27, n.º 4 (agosto de 2013): 231–56. http://dx.doi.org/10.1080/17480930.2012.680754.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Yang, Liuhua, Hongjiang Wang, Aixiang Wu, Hong Li, Arlin Bruno Tchamba y Thomas A. Bier. "Shear thinning and thickening of cemented paste backfill". Applied Rheology 29, n.º 1 (1 de enero de 2019): 80–93. http://dx.doi.org/10.1515/arh-2019-0008.

Texto completo

Resumen

Abstract Cemented paste backfill (CPB) is considered to be a concentrated suspension in which tailings are bonded together by the hydraulic binder and water, and it has a high solid volume concentration (≥50 vol.%). Although the shear thinning and thickening of CPB has been extensively reported in literature, the shear history effects have been ignored in previous studies. In this paper, by using rheometer and Focused Beam Reflectance Measurement, the relationship between the rheological properties and microstructure of the paste under different shear histories was studied. The results have shown that at a low shear rate, CPB revealed shear thinning, low yield stress and low index parameters; while exhibited shear thickening, high yield stress and high consistency index when at high shear rates of shear history. This agreed with the general trends shown in the FBRM analysis. It was proposed that the action of shear is beneficial to particle dispersion, whereas a high shear rate history tends to promote the aggregation of particles. It was revealed that both shear thinning and thickening of paste are related to the situation of particles (flocculation, dispersion and aggregation), and shear history effects play an important role in rheological properties of CPB.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Wang, Kun, Peng Yang, Wensheng Lyu y Zhixiang Lin. "Research of Cemented Paste Backfill in Offshore Environments". IOP Conference Series: Earth and Environmental Science 108 (enero de 2018): 042082. http://dx.doi.org/10.1088/1755-1315/108/4/042082.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Yi, X. W., G. W. Ma y A. Fourie. "Compressive behaviour of fibre-reinforced cemented paste backfill". Geotextiles and Geomembranes 43, n.º 3 (junio de 2015): 207–15. http://dx.doi.org/10.1016/j.geotexmem.2015.03.003.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Gao, Rugao, Keping Zhou, Wei Liu y Qifan Ren. "Correlation between the Pore Structure and Water Retention of Cemented Paste Backfill Using Centrifugal and Nuclear Magnetic Resonance Methods". Minerals 10, n.º 7 (8 de julio de 2020): 610. http://dx.doi.org/10.3390/min10070610.

Texto completo

Resumen

This research combines a centrifugal test and nuclear magnetic resonance (NMR) technology to study the water retention capacity of the cemented paste backfill. Backfill samples with cement–tailings ratios of 1:4, 1:8, and 1:12, and solid concentrations of 71%, 74%, 77%, 80%, and 83% respectively, were prepared for the test. The relative centrifugal force ( RCF ) required for accurate testing and the T2 cutoff value that characterizes the water retention capacity were obtained through an NMR test on the backfill samples after centrifugation in saturated conditions. Based on the soil–water characteristic curve (SWCC), the NMR pore water characteristic distribution model was established, and the pore size distribution and effective water retention characteristics were analyzed. This study shows that when the rotating speed is between 1500 and 4000 rpm, the R C F of the backfill ranges from 125.8 to 894.4 g/min , and the T2 cutoff value will vary from 3 to 10 ms. With an increase in solid concentration of the backfill, both the RCF and T2 cutoff value decline. The Scanning Electron Microscope (SEM) analysis confirms that an increase in the solid concentration and cement–tailings ratio will lead to obvious bimodal characteristics of the pore size distribution curve of the backfill. In addition, the porosity will decrease, the critical pore value, which represents a value to distinguish pores with different movable fluid retention capabilities and characterizes the pore size classification, will become smaller, and the pore size distribution will become more diverse. These changes indicate that a high-concentration backfill can effectively reduce the flow of a fine-grained matrix with large pores.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Thompson, B. D., W. F. Bawden y M. W. Grabinsky. "In situ measurements of cemented paste backfill at the Cayeli Mine". Canadian Geotechnical Journal 49, n.º 7 (julio de 2012): 755–72. http://dx.doi.org/10.1139/t2012-040.

Texto completo

Resumen

Cemented paste backfill (CPB) is accepted as the optimal backfilling material for many underground mines. However, the lack of in-stope backfill pressure data poses fundamental problems from both operational and research standpoints. In response to the requirement for in situ data, a comprehensive field instrumentation project has been conducted. Results are presented here for two stopes at the Cayeli Mine, where geotechnical instruments were installed at the barricades and throughout the stopes. Measurements from a large (slow rise rate) stope with high binder content CPB demonstrated a rapid departure from hydrostatic loading, resulting in relatively low barricade pressures. Conversely, data from a smaller (fast rise rate) stope with lower binder content CPB demonstrated that when cement hydration is retarded, high barricade pressures occur. These examples illustrate the relationship between CPB rise rate and the moderating effect of cement hydration on in situ pressures, which ultimately control barricade pressures. Once CPB gains shear strength, arching of pressures occurs. In situ pressures were reduced with proximity to stope walls and further, under stope access brows, demonstrating that barricade location influences barricade loads. The application of real-time pressure monitoring of pastefill barricades has been demonstrated as an important tool in optimizing operational backfilling efficiency.

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Liu, Jiandong, Guichen Li, Sen Yang y Jiandong Huang. "Prediction Models for Evaluating the Strength of Cemented Paste Backfill: A Comparative Study". Minerals 10, n.º 11 (21 de noviembre de 2020): 1041. http://dx.doi.org/10.3390/min10111041.

Texto completo

Resumen

Cemented paste backfill (CPB) is widely used in underground mining, and attracts more attention these years as it can reduce mining waste and avoid environmental pollution. Normally, to evaluate the functionality of CPB, the compressive strength (UCS) is necessary work, which is also time and money consuming. To address this issue, seven machine learning models were applied and evaluated in this study, in order to predict the UCS of CPB. In the laboratory, a series of tests were performed, and the dataset was constructed considering five key influencing variables, such as the tailings to cement ratio, curing time, solids to cement ratio, fine sand percentage and cement types. The results show that different variables have various effects on the strength of CPB. The optimum models for predicting the UCS of CPB are a support vector machine (SVM), decision tree (DT), random forest (RF) and back-propagation neural network (BPNN), which means that these models can be directly applied for UCS prediction in future work. Furthermore, the intelligent model reveals that the tailings to cement ratio has the most important influence on the strength of CPB. This research can boost CPB application in the field, and guide the artificial intelligence application in future mining.

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Zhao, Jian-wen, Xin-min Wang, Kang Peng y Shuai Li. "Utilization of Foaming Technology in Cemented Paste Backfill of High-Mud Superfine Unclassified Tailings". Advances in Materials Science and Engineering 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/6157869.

Texto completo

Resumen

Due to high-mud content in superfine unclassified tailings (SUT), the viscosity of cemented paste backfill (CPB) is high and its pipeline transportation properties are poor. Foaming technology was introduced to prepare a new three-phase flow backfill (TFB) using a foaming machine. Then the rheological parameters of TFB with different bubble ratio were measured and their pipeline transportation properties were simulated by Fluent. Besides, the simulation results were further verified by a semi-industrial loop test. The results indicate that the optimum ratio of TFB is a cement-sand ratio of 1 : 8, mass concentration of 70%, and bubble ratio of 20%. Compared with CPB, the decrease of bleeding rate, viscosity, and resistance loss of TFB is 27%, 25%, and 30%, respectively. Therefore, foaming technology is an innovative and feasible solution for high-mud CPB in reducing viscosity, decreasing resistance loss, and improving pipeline transporting efficiency.

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Wang, Haoyu, Xianhui Zhao, Boyu Zhou, Yonghui Lin y Han Gao. "Performance Optimization and Characterization of Soda Residue-Fly Ash Geopolymer Paste for Goaf Backfill: Beta-Hemihydrate Gypsum Alternative to Sodium Silicate". Materials 13, n.º 24 (8 de diciembre de 2020): 5604. http://dx.doi.org/10.3390/ma13245604.

Texto completo

Resumen

Solid waste soda residue (SR), as an industrial pollutant of water, air and soil environment, can be utilized to prepare the low-calcium fly ash (FFA)-based geopolymer paste activated by sodium silicate (NS) solution for goaf backfill. However, the high addition of NS produces the high cost and high strength of synthesized backfill material in the previous study. The objective of this research is to investigate the cost optimization method and performance evaluation of SR-FFA-based geopolymer backfill paste. The alkaline beta-hemihydrate gypsum (BHG) alternative to partial NS was proposed. Scanning electron microscopy (SEM), X-ray diffraction (XRD) as well as Fourier transform infrared spectrometer (FTIR) tests were performed to clarify the role of BHG and evaluate the microstructures and products of backfill pastes. The results show that 10% BHG alternative ratios effectively improve fluidity, setting time and compressive strength to satisfy the performance requirement of goaf backfill material. The gel products in the optimal backfill paste C4 with 10% BHG alternative ratios are determined as the coexistence of C-S-H gel, (N,C)-A-S-H gel and CaSO4·2H2O at 28 d. The research results can make extensive utilization of SR and FFA in cemented paste backfill to synthesize cleaner material at a larger scale.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Hu, Jianhua, Xiaotian Ding, Qifan Ren, Zhouquan Luo y Quan Jiang. "Effect of Incorporating Waste Limestone Powder into Solid Waste Cemented Paste Backfill Material". Applied Sciences 9, n.º 10 (20 de mayo de 2019): 2076. http://dx.doi.org/10.3390/app9102076.

Texto completo

Resumen

To effectively reuse waste limestone powder, which is a major solid waste around mines, we replaced limestone powder back into a part of cement in solid waste cemented paste backfill (SWCPB) and studied the parameters of pore structures. To optimize the pore microstructure characteristics of SWCPB in mines, two different components and grade tailings were selected. The samples were characterized by scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) to examine the pore properties and microstructure of SWCPB. The results showed that (1) at the later curing stage, with the optimization of pore characteristics and microstructure through the limestone powder admixture, the strength of SWCFB was guaranteed at a 20% replacement degree of cement. (2) Porosity, macropore proportion, and the average pore radius all negatively correlated with limestone powder content, which were reduced by 7.15%, 46.35%, and 16.37%, respectively. (3) Limestone powder as a crystal nucleus participated in the hydration reaction and was embedded into the product to enhance the strength.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Zhang, Zhonghui, Yuanhui Li, Lei Ren, Zhenbang Guo, Haiqiang Jiang y Na Liu. "Evaluation of Rheological Parameters of Slag-Based Paste Backfill with Superplasticizer". Advances in Materials Science and Engineering 2021 (16 de enero de 2021): 1–11. http://dx.doi.org/10.1155/2021/6673033.

Texto completo

Resumen

The use of blast furnace slag-based binders in cemented paste backfill (CPB) has become increasingly popular in China, due to its low cost and superior early-age strength. Increasing the solid content can increase the strength of CPB, but it will lead to a decrease in its fluidity. As a chemical admixture that can improve CPB slurry fluidity, superplasticizer is gaining increased interest in the field of CPB. In this study, the effects of superplasticizer types and dosages, curing time, solid content, and binder content on the rheological properties of fresh CPB made of blast furnace slag-based binder (Slag-CPB) were studied. For Slag-CPB samples, polycarboxylate (PC) has the best water-reducing effect, followed by polymelamine sulfonate (PMS) and polynaphthalene sulfonate (PNS). In the absence of a superplasticizer, the shear yield stress and plastic viscosity of Slag-CPB are lower than those of CPB made of ordinary Portland cement (OPC-CPB). The water-reducing effect of PC on OPC-CPBs samples is stronger than that of Slag-CPB samples. The degradation rate of the water-reducing effect in slag-based samples is higher than that in cement-based samples. The effect of PC is affected by solid content and binder content. These results will contribute to a better understanding of the rheological behavior of Slag-CPB with superplasticizer.

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Festugato, L., A. Fourie y N. C. Consoli. "Cyclic shear response of fibre-reinforced cemented paste backfill". Géotechnique Letters 3, n.º 1 (11 de enero de 2013): 5–12. http://dx.doi.org/10.1680/geolett.12.00042.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

DeVos, Ken y Rens Verburg. "CEMENTED PASTE BACKFILL LEACHATE CHARACTERISTICS - SNAP LAKE DIAMOND MINE1". Journal American Society of Mining and Reclamation 2006, n.º 2 (30 de junio de 2006): 476–93. http://dx.doi.org/10.21000/jasmr06020476.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Fridjonsson, E. O., A. Hasan, A. B. Fourie y M. L. Johns. "Pore structure in a gold mine cemented paste backfill". Minerals Engineering 53 (noviembre de 2013): 144–51. http://dx.doi.org/10.1016/j.mineng.2013.07.017.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Jiao, Hua-zhe, Ai-xiang Wu, Hong-jiang Wang, Sheng-kai Yang, Rui Li y Yun-tao Xiao. "The Influence of Cemented Paste Backfill on Groundwater Quality". Procedia Earth and Planetary Science 2 (2011): 183–88. http://dx.doi.org/10.1016/j.proeps.2011.09.030.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ofrecemos descuentos en todos los planes premium para autores cuyas obras están incluidas en selecciones literarias temáticas. ¡Contáctenos para obtener un código promocional único!