scholarly journals Influence of Wood Fly Ash on Concrete Properties through Filling Effect Mechanism

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7164
Author(s):  
Ivan Gabrijel ◽  
Marija Jelčić Rukavina ◽  
Nina Štirmer
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plants ◽  
Heat Liberation ◽  
Heat Of Hydration ◽  
Operating Conditions ◽  
Capillary Absorption ◽  
Cement Replacement ◽  
Combustion Technology ◽  
Compressive Strength Of Concrete

This paper presents the results of an experimental study aimed at determining the influence of wood fly ash (WFA) from three Croatian power plants on the properties of concrete. First, the chemical and physical properties of WFA’s were determined. It was found that these properties are highly influenced by combustion technology, the type and parts of wood used as fuel, and the local operating conditions. Subsequently, workability, heat of hydration, stiffness development, 28-day compressive strength, apparent porosity, and capillary absorption were determined on concrete mixes prepared with WFA as cement replacement from 5–45% by weight. Cement replacement up to 15% with the finest WFA accelerated hydration, stiffness development, and increased compressive strength of concrete up to 18%, while replacement with coarser WFA’s led to a decrease in compressive strength of up to 5% and had more gradual heat liberation. The dominant effect that could explain these findings is attributed to the filler and filling effect mechanisms. At the same time replacement content of up to 45% had very little effect on capillary absorption and could give concrete with sufficiently high compressive strength to be suitable for construction purposes.

scholarly journals PROPERTIES OF CEMENT-FLY ASH MIXTURES WITH SUBSTANDARD FLY ASH AS A PARTIAL CEMENT AND FINE AGGREGATE REPLACEMENT

2021 ◽  
Vol 11 (3) ◽  
pp. 71-88
Author(s):  
Piseth Pok ◽  
Parnthep Julnipitawong ◽  
Somnuk Tangtermsirikul
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Sulfate ◽  
Chloride Penetration ◽  
The Other ◽  
Fine Aggregate ◽  
Carbonation Depth ◽  
Cement Replacement ◽  
Durability Properties ◽  
Compressive Strength Of Concrete

This research investigated the effects of using a substandard fly ash as a partial cement and/or fine aggregate replacement on the basic and durability properties of cement-fly mixtures. Experimental results showed that utilizing the substandard fly ash led to increase in water requirement and autoclave expansion of pastes. The strength activity indexes of the substandard fly ash passed the requirements of TIS 2135 and ASTM C618. Utilization of the substandard fly ash as cement replacement led to higher expansion of mortar bars stored in water and sodium sulfate expansion as compared to that of the OPC mixture. However, sodium sulfate resistance of mortar mixtures improved when utilizing the substandard fly ash as sand replacement material. The compressive strength of concrete at all ages was higher with the increase of the content of the substandard fly ash as sand replacement material. When the substandard fly ash was used as cement replacement material in concrete, the carbonation depth increased. On the other hand, the use of the substandard fly ash as sand replacement material decreased the carbonation depth of the concrete. Utilization of the substandard fly ash, both to replace cement and/or fine aggregate, reduced the rapid chloride penetration of the concrete.

"Recent Patents on the Triboelectrostatic Separation of Fly Ash"

2019 ◽  
Vol 13 ◽  
Author(s):  
Haisheng Li ◽  
Wenping Wang ◽  
Yinghua Chen ◽  
Xinxi Zhang ◽  
Chaoyong Li
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
High Efficiency ◽  
Separation Efficiency ◽  
High Reliability ◽  
Operating Conditions ◽  
Security Requirements ◽  
Unburned Carbon ◽  
Efficient Operation ◽  
Triboelectrostatic Separation

Background: The fly ash produced by coal-fired power plants is an industrial waste. The environmental pollution problems caused by fly ash have been widely of public environmental concern. As a waste of recoverable resources, it can be used in the field of building materials, agricultural fertilizers, environmental materials, new materials, etc. Unburned carbon content in fly ash has an influence on the performance of resource reuse products. Therefore, it is the key to remove unburned carbon from fly ash. As a physical method, triboelectrostatic separation technology has been widely used because of obvious advantages, such as high-efficiency, simple process, high reliability, without water resources consumption and secondary pollution. Objective: The related patents of fly ash triboelectrostatic separation had been reviewed. The structural characteristics and working principle of these patents are analyzed in detail. The results can provide some meaningful references for the improvement of separation efficiency and optimal design. Methods: Based on the comparative analysis for the latest patents related to fly ash triboelectrostatic separation, the future development is presented. Results: The patents focused on the charging efficiency and separation efficiency. Studies show that remarkable improvements have been achieved for the fly ash triboelectrostatic separation. Some patents have been used in industrial production. Conclusion: According to the current technology status, the researches related to process optimization and anti-interference ability will be beneficial to overcome the influence of operating conditions and complex environment, and meet system security requirements. The intelligent control can not only ensure the process continuity and stability, but also realize the efficient operation and management automatically. Meanwhile, the researchers should pay more attention to the resource utilization of fly ash processed by triboelectrostatic separation.

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

2021 ◽  
Vol 323 ◽  
pp. 8-13
Author(s):  
Jadambaa Temuujin ◽  
Damdinsuren Munkhtuvshin ◽  
Claus H. Ruescher
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Power Stations ◽  
Thermal Power Stations ◽  
Coal Ashes ◽  
By Products

With a geological reserve of over 170 billion tons, coal is the most abundant energy source in Mongolia with six operating thermal power stations. Moreover, in Ulaanbaatar city over 210000 families live in the Ger district and use over 800000 tons of coal as a fuel. The three thermal power plants in Ulaanbaatar burn about 5 million tons of coal, resulting in more than 500000 tons of coal combustion by-products per year. Globally, the ashes produced by thermal power plants, boilers, and single ovens pose serious environmental problems. The utilization of various types of waste is one of the factors determining the sustainability of cities. Therefore, the processing of wastes for re-use or disposal is a critical topic in waste management and materials research. According to research, the Mongolian capital city's air and soil quality has reached a disastrous level. The main reasons for air pollution in Ulaanbaatar are reported as being coal-fired stoves of the Ger residential district, thermal power stations, small and medium-sized low-pressure furnaces, and motor vehicles. Previously, coal ashes have been used to prepare advanced materials such as glass-ceramics with the hardness of 6.35 GPa, geopolymer concrete with compressive strength of over 30 MPa and zeolite A with a Cr (III) removal capacity of 35.8 mg/g. Here we discuss our latest results on the utilization of fly ash for preparation of a cement stabilized base layer for paved roads, mechanically activated fly ash for use in concrete production, and coal ash from the Ger district for preparation of an adsorbent. An addition of 20% fly ash to 5-8% cement made from a mixture of road base gave a compressive strength of ~ 4MPa, which exceeds the standard. Using coal ashes from Ger district prepared a new type of adsorbent material capable of removing various organic pollutants from tannery water was developed. This ash also showed weak leaching characteristics in water and acidic environment, which opens up an excellent opportunity to utilize.

Development of Sediment Brick Utilizing Reservoir Sediment and Fly Ash

2013 ◽  
Vol 420 ◽  
pp. 276-280
Author(s):  
Bashar S. Mohammed ◽  
Ean Lee Woen ◽  
M.A. Malek ◽  
Wong Leong Sing ◽  
Nor Aishah Abbas ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plants ◽  
Gravitational Force ◽  
Electrical Power ◽  
Research Work ◽  
Flowing Water ◽  
Reservoir Sediment ◽  
Load Bearing ◽  
Hydroelectric Plants

Electrical companies generate electricity mainly from two major types of plant; hydroelectric plants and thermal plants. Hydroelectric is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water through dams operation. The sedimentation of such dams over years will cause large capacity losses of the dams. Thermal plants generate electricity through coal-fired power plants which produce millions tons of fly ash yearly. This fly ash accumulates rapidly and causes enormous problems of disposal. Therefore, the research work presented in this paper is dealing with utilizing reservoir sediment and fly as to form brick under pressure. Sediment brick can be produced as a load bearing brick with compressive strength is greater than 7 N/mm2.

scholarly journals Research on Mechanical Performance & Behaviour of Geopolymer Concrete Subjected to Elevated Temperatures

2019 ◽  
Vol 8 (2S8) ◽  
pp. 883-887
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Geopolymer Concrete ◽  
Sem Images ◽  
Before And After ◽  
Alkaline Conditions ◽  
Compressive Strength Of Concrete

The investigative studies on mechanical performance & behaviour, of Geopolymer Concrete (GPC) before and after the exposure to elevated temperatures (of 200 0 C -1000 0 C with an increment of 100 0 C). Indicate that the GPC Specimens Exhibited better Compressive strength at higher temperatures than that of those made by regular OPC Concrete with M30 Grade. The chronological changes in the geopolymeric structure upon exposure to these temperatures and their reflections on the thermal behaviour have also been explored. The SEM images indicate GPC produced by fly ash , metakaolin and silica fume, under alkaline conditions form Mineral binders that are not only non-flammable and but are also non-combustible resins and binders. Further the Observations drawn disclose that the mass and compressive strength of concrete gets reduced with increase in temperatures.

scholarly journals Kuat Tekan Beton Mutu Tinggi dengan Memanfaatkan Fly Ash dan Bubuk Kaca Sebagai Bahan Pengisi

2020 ◽  
Vol 20 (01) ◽  
pp. 61-68
Author(s):  
Siska Apriwelni ◽  
Nugraha Bintang Wirawan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Glass Powder ◽  
Concrete Mixture ◽  
Strength Testing ◽  
Concrete Compressive Strength ◽  
High Quality ◽  
Glass Waste ◽  
Powder Addition ◽  
Compressive Strength Of Concrete

(ID) Penelitian ini membahas pengaruh kuat tekan beton mutu tinggi dengan memanfaatkan limbah fly ash dan limbah kaca. Tujuan dari penelitian ini untuk mengetahui kuat tekan beton pada masing-masing variasi, mengetahui persentase campuran beton untuk menghasilkan kuat tekan maksimum, dan mengetahui apakah fly ash dan serbuk kaca efektif digunakan secara bersamaan sebagai bahan campuran beton. Komposisi fly ash terdiri dari 5 variasi yaitu persentase 0%, 5%, 10%, 15%, dan 20%. Sedangkan untuk komposisi serbuk kaca terdiri dari 2 variasi yaitu persentase 5% dan 10%. Jumlah benda uji 30 buah silinder berukuran diameter 15 cm dan tinggi 30 cm dengan 3 benda uji untuk setiap variasi. Perencanaan campuran beton menggunakan SNI 03-2834-2000 yang dimodifikasi. Pengujian kuat tekan diuji pada umur beton 28 hari. Beton dengan fly ash 0% dan serbuk kaca 10% memiliki kuat tekan paling tinggi dibandingkan dengan beton dengan tambahan fly ash, yaitu 46,77%. Selain itu, dapat disimpulkan bahwa semakin bertambahnya jumlah persentase serbuk kaca yang digunakan menunjukkan bahwa kuat tekan beton semakin bertambah juga. Penambahan fly ash pada campuran beton mempengaruhi kuat tekan beton yang dihasilkan. Pada variasi fly ash 0% memiliki kuat tekan tertinggi baik pada saat campuran serbuk kaca 5%dan 10%. Variasi fly ash 15% adalah kondisi optimum campuran beton dengan kuat tekan beton yaitu 43,31 Mpa. Kedua limbah ini dapat dikombinasikan dan dimanfaatkan dengan baik dan digunakan dalam pembuatan beton mutu tinggi. (EN) This study discusses the effect of high quality concrete by utilizing fly ash and glass waste. The purpose of this study is to determine the compressive strength of concrete in each variation, to determine the contribution of concrete to produce compressive strength, and to find out that fly ash and glass powder are effectively used in full as a concrete admixture. Fly ash composition consists of 5 variations, namely the percentage of 0%, 5%, 10%, 15%, and 20%. While for the composition of glass powder consists of 2 variations, namely the percentage of 5% and 10%. The number of specimens is 30 cylinders with a diameter of 15 cm and a height of 30 cm with 3 specimens for each variation. Concrete mixture planning using SNI 03-2834-2000 was developed. Compressive strength testing on concrete age 28 days. Concrete with 0% fly ash and 10% glass powder have the highest compressive strength compared to concrete with additional fly ash, which is 46.77%. In addition, it can increase the amount of glass powder addition that is used to show the concrete compressive strength is increasing as well. The addition of fly ash in the concrete mixture has an effect on the compressive strength of the concrete produced. In the variation of 0% fly ash has the highest compressive strength when the glass powder mixture of 5% and 10%. The 15% fly ash variation is the optimal concrete mixture with compressive strength of 43.31 MPa. These two wastes can be combined and utilized properly and are used in making high quality concrete.  

Experimental Study on Alkali-Activated Slag-Lithium Slag-Fly Ash Environmental Concrete

2011 ◽  
Vol 287-290 ◽  
pp. 1237-1240
Author(s):  
Lan Fang Zhang ◽  
Rui Yan Wang
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Alkali Activated Slag ◽  
Percent Increase ◽  
Compressive Strength Of Concrete ◽  
Activated Slag ◽  
Lithium Slag ◽  
Alkali Activated

The aim of this paper is to study the influence of lithium-slag and fly ash on the workability , setting time and compressive strength of alkali-activated slag concrete. The results indicate that lithium-slag and fly-ash can ameliorate the workability, setting time and improve the compressive strength of alkali-activated slag concrete，and when 40% or 60% slag was replaced by lithium-slag or fly-ash, above 10 percent increase in 28-day compressive strength of concrete were obtained.

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