scholarly journals Utilization of ash from power plants for high embankments on soft soil

2018 ◽  
Vol 239 ◽  
pp. 05017 ◽  
Author(s):  
Sanja Jocković ◽  
Veljko Pujević ◽  
Miloš Marjanović
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Soil Mechanics ◽  
Soft Soil ◽  
Physical And Mechanical Properties ◽  
Environmental Issue ◽  
Engineering Properties ◽  
Environmental Requirements ◽  
Leaching Behaviour ◽  
Railway Substructure

The ash landfills are a major environmental issue. The use of ash for the highway and railway substructure achieves a double benefit: it significantly reduces the deposited quantities of ash as well as the consumption of natural materials such as crushed stone, gravel and sand. The investigation of engineering properties of fly ash from the power plant in Serbia was conducted at the Laboratory of Soil Mechanics at the Faculty of Civil Engineering in Belgrade. Relevant physical and mechanical properties of ash and mixtures with binders (cement/lime) were investigated. The ash was also tested from the aspect of the potential environmental impact, which primarily depends on the leaching behaviour of the present trace elements. The results of the study showed that fly ash meets technical and environmental requirements and that has the potential for use in highway substructure, such as construction of embankments and stabilization of soft soils. Benefits of utilization of ash and slag was shown in the case of the construction of a high embankment on soft soil on the highway section Obrenovac-Ub in Serbia.

scholarly journals The Alternatives to Traditional Materials for Subsoil Stabilization and Embankments

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3018 ◽  
Author(s):  
Mirjana Vukićević ◽  
Miloš Marjanović ◽  
Veljko Pujević ◽  
Sanja Jocković
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Power Plants ◽  
Soil Stabilization ◽  
Soft Soil ◽  
Physical And Mechanical Properties ◽  
Engineering Properties ◽  
High Plasticity ◽  
Natural Materials ◽  
Positive Effects

Major infrastructure projects require significant amount of natural materials, often followed by the soft soil stabilization using hydraulic binders. This paper presents the results of a laboratory study of alternative waste materials (fly ash and slag) that can be used for earthworks. Results of high plasticity clay stabilization using fly ash from Serbian power plants are presented in the first part. In the second part of the paper, engineering properties of ash and ash-slag mixtures are discussed with the emphasis on the application in road subgrade and embankment construction. Physical and mechanical properties were determined via following laboratory tests: Specific gravity, grain size distribution, the moisture–density relationship (Proctor compaction test), unconfined compressive strength (UCS), oedometer and swell tests, direct shear and the California bearing ratio (CBR). The results indicate the positive effects of the clay stabilization using fly ash, in terms of increasing strength and stiffness and reducing expansivity. Fly ashes and ash-slag mixtures have also comparable mechanical properties with sands, which in combination with multiple other benefits (lower energy consumption and CO2 emission, saving of natural materials and smaller waste landfill areas), make them suitable fill materials for embankments, especially considering the necessity for sustainable development.

scholarly journals Fly ash and slag utilization for the Serbian railway substructure

Transport ◽  
2016 ◽  
Vol 33 (2) ◽  
pp. 389-398 ◽  
Author(s):  
Mirjana Vukićević ◽  
Zdenka Popović ◽  
Jovan Despotović ◽  
Luka Lazarević
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Thermal Power Plant ◽  
Power Plants ◽  
Thermal Power ◽  
Cement Industry ◽  
Engineering Properties ◽  
Thermal Power Plants ◽  
Nikola Tesla ◽  
Railway Substructure

Approximately 7 million tons of fly ash and slag are produced in thermal power plants in Serbia every year, only 3% of which is used in the cement industry. About 300 million tons of the ash-slag mixture are disposed in landfills, occupying an area of approximately 1600 hectares and generating environmental issues. Fly ash from Serbian power plants has pozzolanic properties and due to low concentration of calcium compounds (less than 10% CaO), they do not have self-cementing properties. According to the ASTM C618-15, this ash is from class F. According to the European Standard EN 197-1:2011, this ash is siliceous (type V) ash. From April 2014 to May 2015, an investigation of engineering properties of fly ash and mixtures of fly ash and slag from landfill (without or with binders of cement/lime) was conducted at the Laboratory of Soil Mechanics at the Faculty of Civil Engineering of the University of Belgrade (Serbia) and at the Institute for Testing of Materials – IMS Institute in Belgrade. The laboratory test results were showed in the study ‘Utilization of fly ash and slag produced in the TPP JP EPS thermal power plants for construction of railways’. Four kinds of waste materials from Serbian power plants were laboratory tested: (a) an ash-slag mixture from landfills at the ‘Nikola Tesla A’ thermal power plant; (b) fly ash from silos in the ‘Nikola Tesla B’ thermal power plant; (c) an ash-slag mixture from landfills at the ‘Kostolac A’ and ‘Kostolac B’ thermal power plants and ‘Srednje kostolačko ostrvo’ landfill; (d) fly ash from the ‘Kostolac’ thermal power plant. The following physical and mechanical properties of ash and mixtures were investigated: grain size distribution, Atterberg limits, specific gravity, moisture-density relationship, shear strength parameters in terms of effective stresses, California Bearing Ratio (CBR), and deformation parameters. The paper presents the results of laboratory tests of the materials with and without binders, and based on the laboratory results and previous research, the paper presents possibilities of using fly ash and slag for the construction of railway substructure in the planned construction and reconstruction of railway network in Serbia. The obtained results indicate that tested fly ash and ash-slag mixture have met the technical requirements and that they have the potential to be used in railway substructure.

scholarly journals Synthesis of Geopolymer Based Class-F Fly Ash Aggregates and its Composite Properties in Concrete

2014 ◽  
Vol 60 (1) ◽  
pp. 55-75 ◽  
Author(s):  
P. Gomathi ◽  
A. Sivakumar
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Physical And Mechanical Properties ◽  
Engineering Properties ◽  
Polymerization Reaction ◽  
Hardened Concrete ◽  
Different Types ◽  
Class F Fly Ash ◽  
Ash Aggregates ◽  
Class F

Abstract This study explores the influence of alkali activators on the initiation of polymerization reaction of alumino-silicate minerals present in class-F fly ash material. Different types of fly ash aggregates were produced with silicate rich binders (bentonite and metakaolin) and the effect of alkali activators on the strength gain properties were analyzed. A comprehensive examination on its physical and mechanical properties of the various artificial fly ash aggregates has been carried out systematically. A pelletizer machine was fabricated in this study to produce aggregate pellets from fly ash. The efficiency and strength of pellets was improved by mixing fly ash with different binder materials such as ground granulated blast furnace slag (GGBS), metakaolin and bentonite. Further, the activation of fl y ash binders was done using sodium hydroxide for improving its binding properties. Concrete mixes were designed and prepared with the different fly ash based aggregates containing different ingredients. Hardened concrete specimens after sufficient curing was tested for assessing the mechanical properties of different types concrete mixes. Test results indicated that fly ash -GGBS aggregates (30S2-100) with alkali activator at 10M exhibited highest crushing strength containing of 22.81 MPa. Similarly, the concrete mix with 20% fly ash-GGBS based aggregate reported a highest compressive strength of 31.98 MPa. The fly ash based aggregates containing different binders was found to possess adequate engineering properties which can be suggested for moderate construction works.

scholarly journals Ash as an alternative source of raw materials

2018 ◽  
Vol 60 ◽  
pp. 00026
Author(s):  
Olena Svietkina ◽  
Hanna Tarasova ◽  
Olha Netiaha ◽  
Svitlana Lysytska
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Raw Materials ◽  
Thermal Power ◽  
Physical And Mechanical Properties ◽  
Particle Morphology ◽  
Optical Methods ◽  
Unburned Carbon ◽  
Alternative Source ◽  
Metallurgical Processes

The objective of the work is to study the aluminosilicate fractionation from fly ash, physical and mechanical properties of fly ash derived from the Thermal Power Plants (TPP) wastes. Ash, carbon concentrate (unburned carbon), ash concentrate and products of their treatment with reagents were tested by optical methods. The particle morphology of the objects of research was studied with the scanning electron microscope REM-100. The composition of the ash phases was investigated using the X-ray diffractometer DRON-2. A dispersed analysis of the TPP fly ash suggests a conclusion that it is advisable to separate particles of a narrow grain-size class within the range from 40 to 150 μm with an ash content of about 33%. The first product may be enriched by flotation method. Such a coal product may be used as a reducing medium in metallurgical processes, agglomeration, etc. The calorific capacitance of the concentrate is about 6000 kcal/kg (25000 kJ/kg).

Lightweight Artificial Aggregate Based on Fly Ash for New Rehabilitation Materials

2013 ◽  
Vol 688 ◽  
pp. 146-151 ◽  
Author(s):  
Pavel Sokol ◽  
Rostislav Drochytka ◽  
Vit Cerný ◽  
Ester Helanová
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Power Plants ◽  
Raw Materials ◽  
Physical And Mechanical Properties ◽  
Social Pressure ◽  
High Quality ◽  
Lightweight Materials ◽  
The Past ◽  
Rehabilitation Work

During rehabilitation work are often strict requirements on the use of high quality lightweight materials, including aggregate. Due the constantly increasing social pressure on the optimal use of secondary raw materials is therefore most appropriate to exploit the potential of fly ash as mineral residue from the combustion of ground coal in power plants. Especially filter fly ash has proven to be an adequate substitute for traditional materials in the past. This article deals with the evaluation of physical and mechanical properties of cold-consolidated pellets based on conventional and fluidized fly ash with various cement addition.

Characterization and Effective Utilization of Volcanic Ash for Soil Improvement

2012 ◽  
Vol 248 ◽  
pp. 292-297 ◽  
Author(s):  
Ahmad Rifa’i ◽  
Noriyuki Yasufuku ◽  
Kiyoshi Omine
Keyword(s):  
Volcanic Ash ◽  
Soil Stabilization ◽  
Early Stage ◽  
Soft Soil ◽  
Physical And Mechanical Properties ◽  
Soil Improvement ◽  
Liquid Limit ◽  
Engineering Properties ◽  
Engineering Practice ◽  
Effective Utilization

Volcanic ash becomes environmental important issues as waste material if it is not effectively reduced or reused. In engineering practice, utilization of volcanic ash as substitution material is limited. Indonesia has a large road on soft soil and volcanic ash. The objectives of this paper are focused to study the characterization, classification and utilization of volcanic ash as soil stabilization material which give benefit in engineering practice and also be environmental friendly material. Engineering properties, mineral composition and soil mixture characteristics involve physical and mechanical properties are discussed. Result shows that the effect of addition of volcanic ash after curing time 14 days can improve the engineering properties of soft soil, decrease liquid limit, change curve of grain size distribution, increase bearing capacity, and decrease swelling potential. The soil-volcanic ash mixture with 35% of volcanic ash and 5% of lime is obtained as optimum mixture design. This result is still early stage and need further study.

Engineering Properties of Loess-Fly Ash Mixtures for Roadbase Construction

2000 ◽  
Vol 1714 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Nayyar Zia ◽  
Patrick J. Fox
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Loess Soil ◽  
Engineering Properties ◽  
Simple Method ◽  
Testing Program ◽  
Loess Soils ◽  
High Calcium ◽  
Swell Potential ◽  
Class C

Southwest Indiana has large deposits of wind-blown loess. Similar deposits are found in other states, including Illinois, Kentucky, Iowa, Minnesota, Missouri, and Nebraska. These soils consist of uniform silt with a plasticity index ranging from 0 to 10. This material is suitable for road construction if it is compacted dry of optimum. However, the material is difficult to work after it becomes wet, which commonly results in construction delays. Indiana also has large stockpiles of Class C fly ash from coal-burning power plants. The ash has cementitious properties after hydration (because of the high calcium content) and can be mixed with native soil to produce a weakly cemented soil. Significant interest exists at the Indiana Department of Transportation about the possibility of using Class C fly ash to improve the engineering properties of Indiana loess soils. The results of a laboratory testing program on the properties of loess–fly ash mixtures are presented. Various percentages of fly ash were mixed with loess soil and specimens were permitted to cure for 3 h to 28 days. Pure loess also was tested for comparison. Changes in Atterberg limits, moisture-density relationships, swell potential, and unconfined compression strength are presented. Based on this testing program, a simple method was developed to determine the optimum fly ash content for construction of a workable loess roadbed to avoid delays in construction due to wet conditions. The data presented will be useful for evaluating the stabilization of loess soils with Class C fly ash in Indiana and other states with significant loess soil deposits.

scholarly journals MEASURING THE SOIL COMPACTION ZONE AND PRESSURE OF DEFORMED SOIL ON UNDERGROUND OBJECTS WITH AN ASYMMETRIC CYLINDRICAL TIP

2021 ◽  
pp. 93-100
Author(s):  
Vladimir Suponyev ◽  
Nataliia Fidrovska ◽  
Sergii Balesnyi ◽  
Vitaliy Ragulin ◽  
Svyatoslav Kravets
Keyword(s):  
Mechanical Properties ◽  
Power Plants ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
Maximum Size ◽  
Soil Mass ◽  
Deep Soil ◽  
Frontal Surface ◽  
Before And After ◽  
Deformed State

At trenchless laying of engineering communications in soil the method of static puncture has received wide application at formation of a well. Power plants that implement it have small dimensions, which make them more effective in laying distribution engineering networks in tight urban conditions. Problem. The main disadvantages of the method are the low accuracy of the trajectory and the significant stress in the soil after its compaction, which can lead to the destruction of adjacent underground objects. The first disadvantage is solved by controlling the trajectory of the soil-piercing working body. To solve the second question, it is necessary to know and take into account the specifics of the formation of communication cavities in the soil with an asymmetric tip, which is used for this purpose. Goal. The aim of the work is to establish the regularity of the process of soil puncture by the soil-piercing working body with an asymmetric tip in the form of a cylinder cut at an angle. Methodology. The approaches adopted in the work to solve this goal are based on the theories of deep soil cutting, scientific foundations of soil mechanics, their normative physical and mechanical properties and the law of conservation of soil mass before and after compaction. Results. The calculated dependences for determining the size of the destructive zone from the elastic-plastic deformation of the soil during its puncture by an asymmetric tip with a frontal surface in the form of a beveled cylinder and the pressure of the deformed soil on underground objects are obtained. It is established that the maximum size of the destruction zone and its pressure on underground objects will occur in solid sand. With a tip diameter of 0.3 m, their values can reach 5 m and 0.245 MPa, respectively. Originality. The obtained regularities of soil puncture by a working body with an asymmetric tip in the form of a beveled cylinder made it possible to get an idea of the influence of its deformed state on adjacent communications depending on geometric parameters of the tip and physical and mechanical properties of soils. Practical value. The obtained results can be recommended in the design and determination of technological capabilities of installations for static soil puncture.

Fly Ash-Based Geopolymer: Green Material in Carbon-Constrained Society

2021 ◽  
Vol 321 ◽  
pp. 65-71
Author(s):  
Hoc Thang Nguyen ◽  
Phong Thanh Dang
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Thermal Power ◽  
Bottom Ash ◽  
Coal Ash ◽  
Raw Material ◽  
Engineering Properties ◽  
Gravimetric Analysis ◽  
Green Materials ◽  
Alumino Silicate

Climate change is recognized as a global problem and even the industrial and construction sectors are trying to reduce the green-house gas emissions, especially on CO2 emissions. In Vietnam, the coal-fired thermal power plants are discharging millions of tons of CO2 and coal ash annually. This coal ash is comprised of about 80% of fly ash and the rest is bottom ash. This study would like to introduce one of the potential solutions in a carbon-constrained society that would not only manage the fly ash but also utilized this as raw material for green materials through geopolymerization. The geopolymer-based material has lower energy consumption, minimal CO2 emissions and lower production cost as it valorizes industrial waste. The fly ash containing high alumino-silicate resources from a coal-fired power plant in Vietnam was mixed with sodium silicate and sodium hydroxide solutions to obtain the geopolymeric pastes. The pastes were molded in 10x10x20cm molds and then cured at room temperature for 28 days. The 28-day geopolymer specimens were carried out to test for engineering properties such as compressive strength (MPa), volumetric weight (kg/m3), and water absorption (kg/m3). The microstructure analysis was also conducted for this eco-friendly materials using X ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Differential Thermal Analysis - Thermal Gravimetric Analysis (DTA-TGA).

scholarly journals Improvement of Bearing Capacity of Clay Soil Using Fly Ash

2020 ◽  
Vol 19 (2) ◽  
pp. 55-62
Author(s):  
Abul Hasnat ◽  
Safkat Tajwar Ahmed ◽  
Tahmid Mustafa ◽  
Md. Samiullah Chowdhury ◽  
S. M. Prince
Keyword(s):  
Fly Ash ◽  
Bearing Capacity ◽  
Physical And Mechanical Properties ◽  
Ash Content ◽  
Engineering Properties ◽  
Allowable Bearing Capacity ◽  
Density Relationship ◽  
Time Required ◽  
Unsaturated Condition ◽  
Properties Of Soil

The principal aim of the study is to improve the engineering properties of the soil sample using fly ash as a binding material. Bangladeshi fly ash was used in this study. Effects of fly ash on physical and mechanical properties of soil (Atterberg limits, moisture-density relationship, and unconfined compressive strength) are evaluated in the presence of 0%, 2%, 4%, 5%, 8%, 10%, 15%, 20% & 25% fly ash. For understanding the improvement of engineering properties of soil, a parametric analysis is conducted to determine the allowable bearing capacity, settlement and the time required for the consolidation. The allowable bearing capacity is evaluated using several equations for both saturated and unsaturated conditions. It is found that for 5% fly ash content, the maximum allowable bearing capacity is achieved. The maximum value of allowable bearing capacity is 660.12 kN/m2 in the unsaturated condition. The increment of maximum allowable bearing capacity is 77.74% for 5% fly ash content. The lowest value of the settlement was 336 mm (saturated) and 183 mm (unsaturated) for 25% fly ash content. Considering normally consolidated soil, it is found that the least time required for consolidation is 3.19 years for 25% fly ash content.

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