Experimental and Modeling Study on the Strength of Tailings Backfill in Underground Mine

2014 ◽  
Vol 522-524 ◽  
pp. 1390-1393 ◽  
Author(s):  
Gang Huang ◽  
Si Jing Cai ◽  
Ya Dong Zhang ◽  
Di Wu
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Testing Machine ◽  
Underground Mine ◽  
Strength Testing ◽  
Curing Time ◽  
Mass Ratio ◽  
Theory Analysis ◽  
Object Of Study ◽  
The Mathematical Model

Taking backfill material of underground mine as the object of study, this paper conducts the research on its strength characteristics by using uniaxial compressive strength testing machine at different cement-sand mass ratio and curing time and mass concentration which the method of experiment and theory analysis were used. The model of predicting the strength of tailings backfill was introduced, and its results were identical with the expreimental test after comparing. Therefore, the mathematical model can be used to estimate the strength of tailings backfill after assigning the specific value of tailing backfill. The tested results show that the uniaxial compressive strength of backfill rose with the increase of its concentration, cement-sand ratio, and the curing time; the strength of backfill was not enough to sustain the stope if the curing time is short and the cement-sand ratio is small.

scholarly journals Synthesis of Geopolymer from Inorganic Construction Waste

2013 ◽  
Vol 30 ◽  
pp. 45-51 ◽  
Author(s):  
Arbind Pathak ◽  
Vinay Kumar Jha
Keyword(s):  
Compressive Strength ◽  
Coal Fly Ash ◽  
Chemical Society ◽  
Raw Material ◽  
Curing Temperature ◽  
Alkali Concentration ◽  
Curing Time ◽  
Mass Ratio ◽  
Construction Waste ◽  
Alumino Silicate

Recently, the demolition of old houses and the construction of new buildings in Kathmandu valley are in the peak which in turn generates a huge amount of construction waste. There are two major types of construction wastes which are burden for disposal namely cement-sand-waste (CSW) and the coal fly ash (CFA). These construction wastes are rich source of alumino-silicate and thus used as raw material for the synthesis of geopolymer in this study. Geopolymers have been synthesized from CSW and CFA using NaOH-KOH and Na2SiO3 as activators. Some parameters like alkali concentration, amount of Na2SiO3 and curing time have been varied in order to improve the quality of geopolymeric product. The geopolymerization process has been carried out using 3-8M KOH/NaOH solutions, Na2SiO3 to CFA and CSW mass ratio of 0.25-2.00 and curing time variation from 5-28 days. The curing temperature was fixed at 40ºC in all the cases. 6M NaOH and 7M KOH solutions were found appropriate alkali concentrations while the ratio of sodium silicate to CSW and CFA of 0.5 and 1.75 respectively were found suitable mass ratio for the process of geopolymer synthesis. The maximum compressive strength of only 7.3 MPa after 15 days curing time with CSW raw material was achieved while with CFA, the compressive strength was found to be 41.9 MPa with increasing the curing time up to 28 days.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9334Journal of Nepal Chemical Society Vol. 30, 2012 Page:  45-51 Uploaded date: 12/16/2013    

Experimental Research on Acoustic Emission of Granite under Uniaxial Compression and Splitting Tensile

2012 ◽  
Vol 232 ◽  
pp. 24-27
Author(s):  
Zong Zhan Li ◽  
Jun Lin Tao ◽  
Yi Li
Keyword(s):  
Compressive Strength ◽  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Uniaxial Compressive Strength ◽  
Loading Rate ◽  
Testing Machine ◽  
Peak Stress ◽  
Uniaxial Compression Test ◽  
Peak Strain ◽  
Ae Energy

This paper makes the acoustic emission of granite under uniaxial compression and splitting tensile test by electro-hydraulic testing machine and AE .We studied the relationship of uniaxial compressive strength and splitting tensile strength with the loading rate and AE characteristics of granite .The results show that uniaxial compressive strength and peak strain raise with loading rate, the AE energy gradually increases and get maximum in the 30% of the peak stress in the process of uniaxial compression test, and in the splitting tensile AE energy generates in the initial loading and gets maximum when the granite brittle fracture.

Compressive Strength Characteristics and Volume Change of Sewage Sludge Matrices Solidified by a New Binder

2011 ◽  
Vol 255-260 ◽  
pp. 2819-2823 ◽  
Author(s):  
Yue Xiang Wang ◽  
Jian Wen Ding ◽  
Zhen Shun Hong
Keyword(s):  
Compressive Strength ◽  
Sewage Sludge ◽  
Volume Change ◽  
Curing Time ◽  
Mass Ratio ◽  
Solid Waste Disposal ◽  
Sludge Disposal ◽  
Practical Engineering ◽  
Stone Material ◽  
The Cost

The disposal of sewage sludge is an important issue in practical engineering. This study proposes a new method of solidifying sewage sludge with stone material waste and portland cement. The effects of mass ratio were discussed by the investigations of unconfined compressive strength and volume change of the solidified samples for different curing time. Experimental results show that the binders appeared effective for improving the strength of matrices. it was also found that the volume capacity of matrices increased little, which is important to municipal solid waste disposal. Overall, the work suggests that stone material waste can be utilized as a substitution material for cement to reduce the cost of sludge disposal.

scholarly journals Study on the Strength Evolution Characteristics of Cemented Tailings Backfill from the Perspective of Porosity

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 82
Author(s):  
Hongwei Deng ◽  
Yao Liu ◽  
Weiyou Zhang ◽  
Songtao Yu ◽  
Guanglin Tian
Keyword(s):  
Growth Rate ◽  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Testing Machine ◽  
Relative Strength ◽  
Evolution Model ◽  
Porosity Variation ◽  
Strength Evolution ◽  
Evolution Laws ◽  
Curing Age

At present, the filling mining method is widely used. To study strength evolution laws of cemented tailings backfill (CTB) under different curing ages, in the experiment, mine tailings were used as aggregates, ordinary Portland cement (PC32.5) was used as cementing materials, and different additives (lime and fly ash) were added to make filling samples with the solids mass concentration at 74% and the cement-sand ratios 1:4, 1:6 and 1:8. Based on the nuclear magnetic resonance (NMR) technology, the porosity test of filling samples with curing ages of 3 d, 7 d and 28 d was carried out, and the uniaxial compressive strength test was carried out on the servo universal material testing machine. The relationship between the uniaxial compressive strength and porosity of backfills and the curing age in the three groups was studied, and change laws of the porosity variation and strength growth rate of backfills were analyzed. Based on the variation in porosity, the strength evolution model of the CTB under different curing ages was established, and the model was fitted and verified with test data. Results show that the uniaxial compressive strength, porosity, porosity variation, and strength growth rate of the three groups of backfills gradually increase with the increase of the curing age, the porosity of backfill basically increases with the decrease of the cement–sand ratio, and the porosity of backfill decreases with the increase of the curing age. Porosity variations and relative strength values of the three groups of backfills under different cement-sand ratios obey an exponential function, and the two have a good correlation, indicating that the established filling strength evolution model can well reflect strength evolution laws of the CTB with the change of curing age.

scholarly journals A Laboratory Scale Synthesis of Geopolymer from Locally Available Coal Fly Ash from Brick Industry

2013 ◽  
Vol 29 ◽  
pp. 18-23
Author(s):  
Rishi Babu Bhandari ◽  
Arvind Pathak ◽  
Vinay Kumar Jha
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Time Variation ◽  
Coal Fly Ash ◽  
Curing Temperature ◽  
Alkali Concentration ◽  
Curing Time ◽  
Mass Ratio ◽  
Maximum Compressive Strength

In this work, geopolymers have been synthesized from coal fly ash (CFA) using KOH and Na2SiO3 as activators. Some parameters such as alkali concentration, amount of Na2SiO3 and curing time have been varied in order to improve the quality of geopolymeric product. The geopolymerization process was carried out using 3-8 M KOH solutions, Na2SiO3 to CFA mass ratio of 0.25-2.00 and curing time variation from 6-28 days. The curing temperature was fixed at 40°C in all the cases. During the variation of KOH concentration, the maximum compressive strength of 6.62 MPa was obtained with CFA treated with 7 M KOH solution. Similarly, with the variation of the mass ratio of Na2SiO3 to CFA, the maximum compressive strength of 28.1 MPa was obtained with Na2SiO3 to CFA mass ratio of 1.75. Furthermore, the compressive strength was found to be increased with increasing curing time and 41.9 MPa was achieved with 28 days of curing time. DOI: http://dx.doi.org/10.3126/jncs.v29i0.9232Journal of Nepal Chemical SocietyVol. 29, 2012Page: 18-23Uploaded date : 12/3/2013 

scholarly journals Experimental Development Process of a New Cement and Gypsum-Cemented Similar Material considering the Effect of Moisture

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Qi Liu ◽  
Shaojie Chen ◽  
Shuai Wang ◽  
Jing Chai ◽  
Dingding Zhang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Moisture Content ◽  
Uniaxial Compressive Strength ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Mass Ratio ◽  
Similar Material ◽  
Residual Moisture ◽  
Similar Materials

A new type of similar material considering water characteristics is developed through orthogonal experiments. The similar material is composed of river sand, barite powder, cement, gypsum, and water. We determine the best test development process. First, the proportion test scheme is designed based on the orthogonal test. Then, the effects of the moisture content, mass ratio of aggregate to binder and other components on the density, uniaxial compressive strength, elastic model, and Poisson’s ratio of similar materials are analyzed by range analysis. Finally, the multiple linear regression equation between the parameters and the composition of similar materials is obtained, and the optimal composition ratio is determined according to the relationship between the test’s influencing factors and the mechanical properties of similar materials. The results show that the selected raw materials and their proportioning method are feasible. The content of barite powder plays a major role in controlling the density and Poisson’s ratio of similar materials. The mass ratio of aggregate to binder is the main factor that affects the uniaxial compressive strength and elastic modulus of similar materials, while the moisture content has the second largest effect on the density, uniaxial compressive strength, elastic modulus, and Poisson’s ratio of similar materials. When the residual moisture content increased from 0 to 4%, the uniaxial compressive strength and elastic modulus of similar materials decrease by 49.5% and 53.3%, respectively, and Poisson’s ratio increases by 54.8%. Determining the residual moisture content that matches the design of similar material model tests is critical to improving the test accuracy and provides a reference to prepare similar materials with different requirements.

scholarly journals Effects of Curing Time on Compressive Strength of Hybrid Ionomer (In Vitro Study)

2017 ◽  
Vol 1 ◽  
Author(s):  
Phoebe Lee Pei ◽  
Rusfian Rusfian ◽  
Astrid Yudhit
Keyword(s):  
Compressive Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Curing Time ◽  
Quartz Tungsten Halogen ◽  
Significant Difference ◽  
Compressive Strength Test ◽  
Experimental Laboratory ◽  
The Mean

<p class="AbstractContent"><strong>Objective:</strong> The aim of this study was to investigate the compressive strength of hybrid ionomer with different curing times which are 20 seconds, 30 seconds, 40 seconds and 50 seconds.</p><p class="AbstractContent"><strong>Methods:</strong> This was an experimental laboratory study with posttest only group design. With the total of 24 samples of hybrid ionomer specimens with disk shape (5mm in diameter and 2mm in thickness) were prepared and polymerized using Quartz Tungsten Halogen (QTH) for each group (n=6) of different curing times 20 seconds, 30 seconds, 40 seconds and 50 seconds respectively. All samples were immersed in distilled water with a dark container and stored in incubator at 37°C for 24 hours before the test. Compressive strength test was done by Universal Testing Machine with crosshead speed of 0.5mm/min. All data were analyzed by one way - ANOVA.</p><p class="AbstractContent"><strong>Results:</strong> The mean and standard deviation of the compressive strength of hybrid ionomer with the curing times 20seconds, 30 seconds, 40 seconds and 50 seconds were 45.6± 0.4648MPa, 46.8 ± 0.8165MPa, 48.5 ± 0.4037MPa, 50.2 ± 0.5193MPa respectively. Statistic analyze showed there was significant difference between the effect of curing time of the compressive strength of hybrid ionomer.</p><p class="AbstractContent"><strong>Conclusion</strong>: The increase of curing times will result an increase of compressive strength of hybrid ionomer.</p>

STRENGTH DEVELOPMENT OF EPOXY GROUTS FOR PIPELINE REHABILITATION

2016 ◽  
Vol 79 (1) ◽  
Author(s):  
Lim Kar Sing ◽  
Siti Nur Afifah Azraai ◽  
Nordin Yahaya ◽  
Libriati Zardasti ◽  
Norhazilan Md Noor
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Testing Machine ◽  
Composite Layer ◽  
Oil And Gas Industry ◽  
Strength Development ◽  
Curing Time ◽  
Repair Work ◽  
Short Period ◽  
Infill Material

Polymeric composites are increasingly being used as infill material in civil engineering applications for repairing damaged structures, including corroded pipelines. In repairing damaged pipelines, combination of composite layer and infill materials is a preferable technique used in oil and gas industry. It is desirable for a repair work to be completed in a short period of time. More importantly, as the repair work is done, the structure is expected to back in service soonest possible to minimize the financial loss due to production interference. This paper investigates the development of tensile and compressive strength of two epoxy grouts over 28 days. This research program aims to improve fundamental understanding of this material and its potential application in repairing damaged pipeline. A total of 80 samples with different curing times were prepared based on manufacturer’s guideline. The samples were then cured in room temperature for 1, 7, 21 and 28 days before tested using universal testing machine. The trend of strength development over time was studied to identify the time at which the grout can be considered capable of serving in service condition. It was found that the compressive and tensile strength of both grouts greater than 70MPa and 14MPa at 1-days curing time, respectively. The strength is about 80% developed for 1-day curing time. When comparing the properties of the tested grouts with previous studies, both grouts were found to have the potential to be used as infill material for repairing damaged pipeline. In addition, for application of compressive strength and tensile strength less than 70MPa and 14MPa, both grouts can be considered as capable to serve its repair purpose after the grout cured for 1 day.  

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