scholarly journals Effect of Electrolytic Manganese Residue in Fly Ash-Based Cementitious Material: Hydration Behavior and Microstructure

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7047
Author(s):  
Yaguang Wang ◽  
Na Zhang ◽  
Yongyu Ren ◽  
Yingtang Xu ◽  
Xiaoming Liu
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Mineralogical Composition ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Hydration Reaction ◽  
29Si Nmr ◽  
Polymerization Degree ◽  
Electrolytic Manganese ◽  
Electrolytic Manganese Residue

Electrolytic manganese residue (EMR) is a solid waste with a main mineralogical composition of gypsum. It is generated in the production of metal manganese by the electrolysis process. In this research, EMR, fly ash, and clinker were blended to make fly ash-based cementitious material (FAC) to investigate the effect of EMR on strength properties, hydration behavior, microstructure, and environmental performance of FAC. XRD, TG, and SEM studied the hydration behavior of FAC. The pore structure and [SiO4] polymerization degree were characterized by MIP and 29Si NMR, respectively. The experimental results indicate that FAC shows excellent mechanical properties when the EMR dosage is 10%. Moderate content of sulfate provided by EMR can promote hydration reaction of FAC, and it shows a denser pore structure and higher [SiO4] polymerization degree in this case. Heavy metal ions derived from EMR can be adsorbed in the hydration products of FAC to obtain better environmental properties. This paper presents an AFt covering model for the case of excessive EMR in FAC, and it importantly provides theoretical support for the recycling of EMR in cementitious materials.

Quantitative evaluation of mineral admixtures on the properties, pore structure, and durability of cement-based composites

2012 ◽  
Vol 19 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Chinlai Lee ◽  
Maochieh Chi ◽  
Ran Huang
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Silica Fume ◽  
Mercury Intrusion Porosimetry ◽  
Cementitious Material ◽  
Mineral Admixtures ◽  
Penetration Test ◽  
Compressive Strength Test ◽  
Testing Data ◽  
Influence Of Water

AbstractThe influence of water/cementitious material ratio, silica fume, and fly ash as partial Portland cement replacement materials on the properties, pore structure, and durability of cement-based composites was evaluated by conducting compressive strength test, mercury intrusion porosimetry test, water absorption, rapid chloride penetration test, and scanning electron microscopy (SEM). Water/cementitious material ratio, and replacement percentage of silica fume and fly ash have significant effects on the pore structure and durability of cement-based composites. Composites with silica fume or fly ash have a denser structure than the control composite on SEM micrographs. Silica fume has about 5–10 times as much effect as fly ash, according to results of multiple linear regression analyses of testing data.

scholarly journals A Comprehensive Study on the Hardening Features and Performance of Self-Compacting Concrete with High-Volume Fly Ash and Slag

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4286
Author(s):  
Zhenghong Yang ◽  
Sijia Liu ◽  
Long Yu ◽  
Linglin Xu
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Free Water ◽  
High Volume ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Main Concern ◽  
Self Compacting Concrete ◽  
Chloride Permeability ◽  
Early Hydration

The main concern of this work is to evaluate the influences of supplementary cementitious materials (fly ash, slag) and a new type of polycarboxylate superplasticizer containing viscosity modifying agents (PCE-VMA) on the performance of self-compacting concrete (SCC). The workability, hydration process, mechanical property, chloride permeability, degree of hydration and pore structure of SCC were investigated. Results indicate that the addition of fly ash and slag slows down early hydration and decreases the hydration degree of SCC, and thus leads to a decline in compressive strengths, especially within the first 7 days. The addition of slag refines pore structure and contributes to lower porosity, and thus the chloride permeability of SCC is decreased during the late hydration stage. Additionally, a new factor of calculated water–binder ratio is put forward, which can directly reflect the free water content of concrete mixture after mixing, and guide the mix proportion design of SCC.

Preparation of Geopolymer Using Electrolytic Manganese Residue

2013 ◽  
Vol 591 ◽  
pp. 130-133 ◽  
Author(s):  
Rong Zhao ◽  
Feng Lan Han
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Boric Acid ◽  
Sodium Silicate ◽  
Raw Materials ◽  
Raw Material ◽  
Electrolytic Manganese ◽  
Electrolytic Manganese Residue ◽  
Calcined Kaolin

In this study, reference the method of preparing cement sand to produce geopolymer, using Electrolytic Manganese Residue(EMR), fly ash, magnesium slag (with boric acid), sodium silicate, sand, calcined kaolin as the main raw materials, focus on the study of using electrolytic manganese residue to produce Geopolymeric cement. Finally, through a series of comparison, we find out the best recipe of Geopolymer preparation, and the best ratio of each raw material is 80% EMR, 10% magnesium slag, 10% fly ash. In this way, the Geopolymer has the best mechanical properties.

scholarly journals Equivalent CO2 Emission and Cost Analysis of Green Self-Compacting Rubberized Concrete

2021 ◽  
Vol 14 (1) ◽  
pp. 137
Author(s):  
Sylvia E. Kelechi ◽  
Musa Adamu ◽  
Abubakar Mohammed ◽  
Ifeyinwa I. Obianyo ◽  
Yasser E. Ibrahim ◽  
...  
Keyword(s):  
Fly Ash ◽  
Co2 Emission ◽  
Calcium Carbide ◽  
Crumb Rubber ◽  
Cementitious Materials ◽  
Strength Properties ◽  
Cementitious Material ◽  
Ternary Blend ◽  
Fine Aggregate ◽  
Concrete Production

Global warming and climate changes are the major environmental challenges globally. With CO2 emission being one of the main greenhouse gases emitted to the environment, and cement and concrete production amounting to about 10% of the global CO2 emission, there is a need for the construction industry to utilize an environmentally sustainable material as an alternative to cement. This study analyzed the cost, CO2 emission and strength properties of green self-compacting concrete (SCC) ternary blend containing fly ash, calcium carbide residue (CCR), and crumb rubber (CR) as a replacement material by volume of cement, cementitious material, and fine aggregate, respectively. Cement was replaced with fly ash at 0 and 40% by volume. CCR was used as a replacement at 5 and 10% by volume of cementitious materials, CR replaced fine aggregate in proportions of 10 and 20% by volume. The result indicated that the mix with 0% fly ash and 20% CR replacement of fine aggregate was the most expensive and had the highest CO2 emission. However, the mix with 10% CR, 40% fly ash, and 10% CCR had the lowest CO2 emission and was therefore the greenest SCC mix. The 28-day maximum compressive strength of 45 MPa was achieved in a mix with 0% CR, 0% fly ash, and 10% CCR, while the utmost 28-day splitting tensile strength of 4.1 MPa was achieved with a mix with 10% CR, 0% fly ash, and 5% CCR, and the highest flexural strength at 28 days was 6.7 MPa and was also obtained in a mix with 0% CR, 0% fly ash, and 5% CCR. In conclusion, a green SCC can be produced by substituting 40% cement with fly ash, 10% fine aggregate with CR, and 10% CCR as a replacement by volume of cementitious material, which is highly affordable and has an acceptable strength as recommended for conventional SCC.

Co-sintering MSWI fly ash with electrolytic manganese residue and coal fly ash for lightweight ceramisite

Chemosphere ◽  
2021 ◽  
Vol 263 ◽  
pp. 127914
Author(s):  
Xinyuan Zhan ◽  
Li’ao Wang ◽  
Lei Wang ◽  
Jian Gong ◽  
Xiang Wang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Mswi Fly Ash ◽  
Electrolytic Manganese ◽  
Electrolytic Manganese Residue
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