scholarly journals The Dosage of Superplasticizer in Cemented Coal Waste Backfill Material Based on Response Surface Methodology

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Qingdong Li ◽  
Guorui Feng ◽  
Yuxia Guo ◽  
Tingye Qi ◽  
Xianjie Du ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Fly Ash ◽  
Response Surface ◽  
Mass Concentration ◽  
Mechanical Performance ◽  
Low Cost ◽  
Ash Content ◽  
Coal Waste ◽  
Backfill Material ◽  
Underground Openings

Cemented coal waste backfill material (CCWBM) is developed for backfilling the goaf in coal mines. As fresh CCWBM slurry is generally transported into underground openings through a pipeline, the fluidity of fresh slurry becomes one of the most important properties. Adding superplasticizer is considered to improve the flow performance of the slurry without alerting the mechanical performance of filling body. The dosage of superplasticizer (SP) is related to filling cost, thus response surface methodology (RSM) is adopted to study the influence of material composition on SP when target slump is 250 mm. The effects of fly ash content, fine gangue ratio, and mass concentration on SP are analyzed using the software of Design-Expert and central composite design (CCD), and models are established for SP. Results show that the SP model coincides greatly with the test results and can be applied to analyze and predict SP in CCWBM. Mass concentration, fly ash content, and fine gangue ratio influence SP from high to low. The interaction of fine gangue ratio and mass concentration between SP is the most significant. The fact that the improved aggregate space model can be applied to analyze the fluidity of CCWBM is proved too. The research results provide guidance for the design and preparation of CCWBM with favourable performance and low cost in practical production.

scholarly journals Statistical Modelling of Ultrasonic Pulse Velocity of Fly Ash Based Geopolymer mortar using response surface methodology

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Muhammad Zahid ◽  
Nasir Shafiq ◽  
Muhammad Ali
Keyword(s):  
Response Surface Methodology ◽  
Fly Ash ◽  
Response Surface ◽  
Mechanical Performance ◽  
Statistical Modelling ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Curing Temperature ◽  
Significance Level

The fly ash based geopolymer has emerged as a capable and sustainable binder material in construction industry. Ultrasonic pulse velocity (UPV) method is a non-destructive technique for investigating the mechanical performance of concrete. Experimental investigation was performed for studying the effect of NaOH Molarity, Na2SiO3/NaOH and curing temperature on the ultrasonic pulse velocity of geopolymer mortar. Experiments were designed based on central composite design (CCD) technique of response surface methodology (RSM). Statistical model was developed and statistically validated and found significant as the difference between adjustable R-squared and predicted R-squared less than 0.2. Finally, the optimized mix proportion was assessed for maximized value of UPV. Experimental validation on the optimized mix reveals the close agreement between experimental and predicted values of UPV with significance level of more than 95%. The proposed technique improves the yield, the reliability of the product and the processes.

Using Response Surface Methodology in Synthesis of Ultrafine Copper Nanoparticles by Electrolysis

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650001 ◽  
Author(s):  
A. Tamilvanan ◽  
K. Balamurugan ◽  
K. Ponappa ◽  
B. Madhan Kumar
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Process Parameters ◽  
Low Cost ◽  
Cu Nanoparticles ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Electrode Gap ◽  
Average Size ◽  
Ultrafine Copper

Electrolysis is a method used for producing copper (Cu) nanoparticles at faster rate and at low cost in ambient conditions. The property of Cu nanoparticles prepared by electrolysis depends on their process parameters. The influence of selected process parameters such as copper sulfate (CuSo4) concentration, electrode gap and electrode potential difference on particle size was investigated. To optimize these parameters response surface methodology (RSM) was used. Cu nanoparticles prepared by electrolysis were characterized by using X-ray diffraction (XRD) and scanning electron microscope (SEM). After reviewing the results of analysis of variance (ANOVA), mathematical equation was created and optimized parameters for producing Cu nanoparticles were determined. The results confirm that the average size of Cu particle at the optimum condition was found to be 17[Formula: see text]nm and they are hexagonal in shape.

Sign in / Sign up

Export Citation Format

Share Document