scholarly journals Optimization of the Process Parameters Controlling the Degree of Amorphization during Mechanical Activation of Clay Using the Taguchi Method

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 15
Author(s):  
Tole ◽  
Habermehl-Cwirzen ◽  
Cwirzen
Keyword(s):  
Taguchi Method ◽  
Mechanical Activation ◽  
Process Parameters ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Main Peak ◽  
Activation Process ◽  
Statistical Tool ◽  
Before And After ◽  
Environmentally Friendly Process

Mechanical activation in a planetary ball mill (BM) is an environmentally friendly process able to enhance the chemical and pozzolanic activity of natural clays. Those materials can be used as supplementary cementitious materials (SCMs) to partially replace Portland cement in concrete. The process parameters of the BM are directly related to the degree of amorphization and thus to the enhancement of the chemical activity. Design of experiments (DOE) is a well-known statistical tool, which can assist in selecting optimized conditions and in obtaining systematic data. However, full factorial design requires a large number of experiment. Taguchi method is based on the use of an Orthogonal Array (OA) to evaluate optimization of the selected factors but with less required experiments. In this study, three factors, each on 2 levels, were selected: ball to powder ratio (B/P) with level 3 and 25, time of grinding with level 5 and 20, and water to powder ratio (W/P) with level 0 and 1. The degree of amorphization (DOA) was selected as the main response for the Taguchi method. DOA was calculated as the ratio between the integral intensities of the main peak of the kaolinite [001] before and after grinding. For dry grinding, the predicted optimized value of DOA complied with the experimental results. Maximized DOA value was achieved for B/P equal to 25 and the grinding duration of 20. This method can be a valuable tool to predict the amorphization degree of minerals present in the natural clay, leading to the optimization of the mechanical activation process.

scholarly journals The Influence of Thermo-Mechanical Activation of Bentonite on the Mechanical and Durability Performance of Concrete

2019 ◽  
Vol 9 (24) ◽  
pp. 5549 ◽  
Author(s):  
Safi Ur Rehman ◽  
Muhammad Yaqub ◽  
Muhammad Noman ◽  
Babar Ali ◽  
Muhammad Nasir Ayaz Khan ◽  
...  
Keyword(s):  
Portland Cement ◽  
Mechanical Activation ◽  
Mechanical Performance ◽  
Experimental Testing ◽  
Construction Material ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Low Carbon ◽  
Acid Attack ◽  
Split Tensile Strength

Despite presenting a very high global warming toll, Portland cement concrete is the most widely used construction material in the world. The eco-efficiency, economy, and the overall mechanical and durability performances of concrete can be improved by incorporating supplementary cementitious materials (SCMs) as partial substitutions to ordinary Portland cement (OPC). Naturally found bentonite possesses pozzolanic properties and has very low carbon footprint compared to OPC. By applying activation techniques, the reactivity of bentonite can be improved, and its incorporation levels can be maximized. In this study, the influence of mechanical and thermo-mechanical activation of bentonite is investigated on properties of concrete. Bentonite was used for 0%, 10%, 15%, 20%, 25%, 30%, and 35% mass replacements of OPC. Mechanical (compressive strength and split tensile strength) and durability (water absorption, sorptivity coefficient, and acid attack resistance) properties were studied. Results of experimental testing revealed that, concrete containing bentonite showed good mechanical performance, while durability was significantly improved relative to control mix. Application of thermo-mechanical activation can enhance the incorporation levels of bentonite in concrete. At 15% and 25%, bentonite produced optimum results for mechanical and thermo-mechanical activation, respectively. Bentonite inclusion is more beneficial to the durability than the mechanical strength of concrete.

Effect of mechanical activation process parameters on the properties of LiFePO4 cathode material

2007 ◽  
Vol 166 (1) ◽  
pp. 211-218 ◽  
Author(s):  
Jae-Kwang Kim ◽  
Gouri Cheruvally ◽  
Jae-Won Choi ◽  
Jong-Uk Kim ◽  
Jou-Hyeon Ahn ◽  
...  
Keyword(s):  
Cathode Material ◽  
Mechanical Activation ◽  
Process Parameters ◽  
Activation Process ◽  
Lifepo4 Cathode

scholarly journals Sulfate Resistance in Cements Bearing Bottom Ash from Biomass-Fired Electric Power Plants

2020 ◽  
Vol 10 (24) ◽  
pp. 8982
Author(s):  
José M. Medina ◽  
María Isabel Sánchez de Rojas ◽  
Isabel F. Sáez del Bosque ◽  
Moisés Frías ◽  
César Medina
Keyword(s):  
Electric Power ◽  
Power Plants ◽  
A Priori ◽  
Bottom Ash ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Blended Cements ◽  
Sulfate Resistance ◽  
Electric Power Plants ◽  
Before And After

To address some of the gaps in the present understanding of the behavior of new supplementary cementitious materials such as bottom ash (BA) from biomass-fired electric power plants in cement manufacture, this study explored the effect of this promising material on the sulfate resistance of the end product. Cement paste prepared with 10% or 20% (previously characterized for mineralogy and chemical composition) BA was Köch–Steinegger tested for sulfate resistance. The hydration products, in turn, were analyzed before and after soaking the reference and experimental cements in sodium sulfate to determine whether the use of the addition hastened microstructural, mineralogical, or morphological decay in the material. The 56 days findings showed that the presence of BA raised binder resistance to sulfate attack. Köch–Steinegger corrosion indices of 1.29 and 1.27 for blended cements OPC + 10 BA and OPC + 20 BA, respectively, were higher than the 1.26 recorded for ordinary Portland cement (OPC). In addition, weight gain was 20.5% and volume expansion was 28.5% lower in the new materials compared to OPC. The products resulting from the external sulfate-cement interaction, gypsum and ettringite, were deposited primarily in the pores present in the pastes. The conclusion drawn is that binders bearing 10% or 20% BA are, a priori, apt for use in the design and construction of cement-based elements exposed to sulfate-laden environments.

Mechanoactivation Of Rice Husk Ash In Laboratory Conditions

2019 ◽  
pp. 20-26
Keyword(s):  
Mechanical Activation ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Silicon Oxide ◽  
Rice Husk Ash ◽  
Pozzolanic Activity ◽  
Maximum Solubility ◽  
Laboratory Conditions ◽  
Before And After ◽  
Mineral Additive

In many rice producing countries of the world, including in Vietnam, various research aimed at using rice husk ash (RHA) as a finely dispersed active mineral additive in cements, concrete and mortars are being conducted. The effect of the duration of the mechanoactivation of the RHA, produced under laboratory conditions in Vietnam, on its pozzolanic activity were investigated in this study. The composition of ash was investigated by laser granulometry and the values of indicators characterizing the dispersion of its particles before and after mechanical activation were established. The content of soluble amorphous silicon oxide in rice husk ash samples was determined by photocolorimetric analysis. The pizzolanic activity of the RHA, fly ash and the silica fume was also compared according to the method of absorption of the solution of the active mineral additive. It is established that the duration of the mechanical activation of rice husk ash by grinding in a vibratory mill is optimal for increasing its pozzolanic activity, since it simultaneously results in the production of the most dispersed ash particles with the highest specific surface area and maximum solubility of the amorphous silica contained in it. Longer grinding does not lead to further reduction in the size of ash particles, which can be explained by their aggregation, and also reduces the solubility of amorphous silica in an aqueous alkaline medium.

Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete

2020 ◽  
Vol 71 (7) ◽  
pp. 775-788
Author(s):  
Quyet Truong Van ◽  
Sang Nguyen Thanh
Keyword(s):  
Fly Ash ◽  
Concrete Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Chloride Permeability ◽  
Cement Replacement ◽  
Fine Grained ◽  
Granulated Blast Furnace Slag ◽  
Compressive Strength Test ◽  
Economic Ground

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA

Application of Taguchi Method for Determining Optimum Process Parameters of PMEDM with SiC Powder Suspended in Dielectric

2013 ◽  
Vol 1 (3) ◽  
pp. 37-42
Author(s):  
Deepak Rajendra Unune ◽  
◽  
Amit Aherwar ◽  
B.P. Pathri ◽  
Jai Kishan ◽  
...  
Keyword(s):  
Taguchi Method ◽  
Process Parameters ◽  
Optimum Process

Evaluation of strength of concrete on different initial exposure condition

2020 ◽  
Vol 13 ◽  
Author(s):  
Sri Ram Krishna Mishra ◽  
Pradeep Kumar Ghosh ◽  
Manoj Kulshreshtha
Keyword(s):  
Portland Cement ◽  
High Strength ◽  
Cementitious Materials ◽  
General Purpose ◽  
Supplementary Cementitious Materials ◽  
Exposure Condition ◽  
Portland Cement Concrete ◽  
Initial Exposure ◽  
Skilled Manpower ◽  
Standard Practices

Background: The previous studies have focused curing effect of mainly on high strength concrete, where strict supervision is maintained. This study is based upon general purpose concreting work for commercial and residential construction in absence of skilled manpower and supervision. Objective: The objective of this study is to establish a thumb rule to provide 7 days initial curing for maintaining quality for unsupervised concreting irrelevant to type of cement and grading. Methods: In this study concrete samples made with locally available commercial cements were cured for various initial exposure. Results: The results shows that concrete cured after a gap of 4 days from the time of de-moulding have given lowest strength as compared to concrete cured in standard practices i.e. where proper curing protocol had been followed. Conclusion: Initial curing is most important aspect of gaining desired strength. The findings after this study shows that curing affects the strength of concrete in variable grading. Initial curing has great importance for concrete with all types of Portland cement. Concrete with supplementary cementitious materials gives lowest strength initially but results higher strength after 28 days as compared to Portland cement.

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