Special Grout for Anchoring Steel Elements with High Proportion of Fly Ash Contaminated by Denitrification Process

2018 ◽  
Vol 276 ◽  
pp. 160-166
Author(s):  
Tomáš Žlebek ◽  
Jakub Hodul ◽  
Rostislav Drochytka
Keyword(s):  
Fly Ash ◽  
Bending Strength ◽  
Flexural Modulus ◽  
Thermal Power ◽  
Optical Microscope ◽  
Silica Sand ◽  
Fluidized Bed Combustion ◽  
Pull Out ◽  
The Impact ◽  
Denitrification Process

This paper focuses on the possible use of fly ash contaminated by denitrification process as filler for special grouts based on epoxy resin. This fly ash is contaminated by combined ammonia ions as a consequence of flue gas denitrification. When mixing this fly ash with water and silica materials, ammonia (NH3) is released, therefore its application in these materials is inappropriate. The use of such fly ash as filler in polymeric substances, e.g. epoxy, polyester or vinyl ester resin, seems to be appropriate. When mixing fly ash with these materials, fly ash particles become coated with a polymeric substance, therefore no toxic ammonia is released. In the experiment, the impact of two kinds of contaminated fly ashes (FA-1, FA-2) and different percentages of filler in a polymer grout was examined on the resulting physical and mechanical properties. It was found that the best properties were by the grout with fly ash from circulating fluidized bed combustion from the Kladno thermal power plant (FA-1) under 45% of filling. This material showed high compressive and three-point bending strength and the flexural modulus was even higher than in the case of the reference material, which contained reference silica sand with optimal round grain shape as filler. Furthermore, chemical resistance of these materials against aggressive liquid solutions used in industrial operations were examined. An ideal grout formula was checked in a cut of an embedded steel element under optical microscope. A pull-out strength test was also performed in the case of the best formulas to determine the anchoring rate of embedded steel rod.

The Suitability of Fly Ash for Use in Concrete According to EN 450 Based on their Particle Size

2018 ◽  
Vol 276 ◽  
pp. 110-115
Author(s):  
Martin Ťažký ◽  
Martin Labaj ◽  
Rudolf Hela
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Catalytic Reduction ◽  
Raw Materials ◽  
Thermal Power ◽  
Combustion Process ◽  
Thermal Power Plants ◽  
Mechanical Parameters ◽  
Fly Ashes ◽  
The Impact

The by-products of energy industry are nowadays often affected by new limits governing the production of harmful gases discharged into the air. These stricter and stricter criteria are often met by electricity producers by changing the combustion process in thermal power plants itself. Nowadays, the SNCR (selective non-catalytic reduction) application is quite common in the combustion process in order to help reduce the nitrogen oxide emission. This article deals with the primary measures of thermal power plants, which in particular consist of a modified treatment of raw materials (coal) entering the combustion process. These primary measures then often cause the formation of fly ash with unsuitable fineness for the use in concrete according to EN 450. The paper presents the comparison of the physico-mechanical parameters of several fly ashes with a different fineness values. The primary task is to assess the impact of non-suitable granulometry in terms of EN 450 on the other physico-mechanical parameters of fly ashes sampled within the same thermal power plant. Several fly ashes produced in the Czech Republic and surrounding countries were evaluated in this way.

Mechanical performance of hybrid woven jute–roselle-reinforced polyester composites

2019 ◽  
Vol 27 (7) ◽  
pp. 407-418 ◽  
Author(s):  
Mohammad Hazim Mohamad Hamdan ◽  
Januar Parlaungan Siregar ◽  
Sabu Thomas ◽  
Maya John Jacob ◽  
Jamiluddin Jaafar ◽  
...  
Keyword(s):  
Composite Plate ◽  
Synthetic Fibre ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Natural Fibre ◽  
Impact Testing ◽  
Void Content ◽  
Fibre Reinforcement ◽  
Pull Out ◽  
The Impact

Natural fibre acts as a significant replacement for the known synthetic fibre that tends to cause critical environmental issues. Hence, the hybridization of natural fibre reinforcement has been considered as one of the strategies in reducing synthetic fibre applications. The current research was conducted to determine the effect of layering sequence on the mechanical performance of hybrid woven jute–roselle. In addition, eight different types of composite plate that consisted of single and hybrid were fabricated through the implementation of hand lay-up method. In this case, each composite plate had to undergo the tensile, flexural and impact testing in order to acquire the effect of varying layering sequences. The results of the present study showed that the hybridization of jute–roselle provided was significant, especially on the flexural and impact performance. Furthermore, the tensile strength and modulus were higher on the JRRJ sample and maximum flexural strength also managed to be recorded by the same sample. However, the maximum flexural modulus only managed to be recorded in sample RRJJ. Meanwhile, the impact testing revealed that the composite plate of sample JJRR had the highest impact strength. The void content for all the samples was acceptable because all of them were less than 7%. Finally, scanning electron microscopic image illustrated that the fractured surfaced of composite sample was typically smooth with less formation of void and fibre pull-out.

scholarly journals Preliminary Analysis of the Ductility and Crack-Control Ability of Engineered Cementitious Composite with Superfine Sand and Polypropylene Fiber (SSPP-ECC)

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2609
Author(s):  
Zhiqing Zhu ◽  
Guojin Tan ◽  
Weiguang Zhang ◽  
Chunli Wu
Keyword(s):  
Crack Width ◽  
Large Scale ◽  
Bending Strength ◽  
Flexural Modulus ◽  
Silica Sand ◽  
Surface Model ◽  
Cementitious Composite ◽  
Crack Control ◽  
Engineered Cementitious Composite ◽  
Pva Fiber

Engineered cementitious composite (ECC) is a potential cement-based material with the abilities of large deformation and crack width control. However, ECC is difficult to popularize in many developing countries because the costs of silica sand and polyvinyl alcohol (PVA) fiber with a surface coating are too high for practical engineering. Therefore, we proposed an economical ECC with superfine river sand and polypropylene (PP) fiber (SSPP-ECC) to replace PVA fiber and silica sand. The SSPP-ECC proposed in this paper is a sustainable material using local material ingredients, which has considerable adaptability for large-scale engineering applications. The 16 groups of specimens were prepared through a factorial design method, curing for four-point bending tests. The bending strength, deflection, flexural modulus of elasticity, and crack width were measured and calculated during the test. The factor analysis of the test results shows that the contents of fiber and fly ash had significant effects on the ductility of SSPP-ECC with an extra combined effect at the same time, and a response surface model with high accuracy was fitted to predict the yield length of SSPP-ECC. The ductility of SSPP-ECC was positively related to its crack-control ability and it was shown that the crack width of SSPP-ECC increased significantly with a high content of superfine sand. This paper proposed a reasonable way to utilize superfine sand and provided the mix proportion of SSPP-ECC with characteristics of deformation hardening and multi-cracking, which may cater to the demands of many concrete components on ductility and crack resistance.

scholarly journals Optimization of the Process of Production of Ceramics From Waste Coal Ash Case Study: The Influence of the Mechanical Activation

2013 ◽  
Vol 7 (1-2) ◽  
Author(s):  
Biljana Angjusheva ◽  
Vojo Jovanov ◽  
Kiril Lisichkov ◽  
Emilija Fidanchevska
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Mechanical Activation ◽  
Bending Strength ◽  
Thermal Power ◽  
Morphological Characteristics ◽  
Coal Ash ◽  
Analytical Form ◽  
Geometrical Factor ◽  
Main Process

Abstract: Fly ash, a waste by-product obtained in a thermal power plant has been a generated problem of the disposal all over the world. Morphological characteristics, physicochemical properties and pozzolanic activity make this waste potential material for production of ceramics. In this study high density ceramics compacts were produced by using fly ash from the power plant REK Bitola, Republic of Macedonia. In order to increase geometrical factor of activity, the mechanical activation of the fly ash was applied. The process of optimization of the main process parameters is conducted, such as time of mechanical activation, sintering temperature and heating rate and their interactions on the properties of obtained dense ceramic porosity and bending strength as a response function. The optimization was performed through application of 3D surface method and the obtained results are presented in the graphical and analytical form using “Statgraphics Centurion” software package.

scholarly journals Cu Addition Effect Analysis on Matrix Of Remelting Piston Aluminium Composite with Silica Sand Reinsforcement to The Impact Strength and Micro Structure on Aluminuim Matrix Composite Using Stir-Casting Method

2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Fajar Paundra ◽  
Teguh Triyono ◽  
Wahyu Purwo Raharjo
Keyword(s):  
Impact Strength ◽  
Matrix Composite ◽  
Testing Machine ◽  
Stir Casting ◽  
Optical Microscope ◽  
Silica Sand ◽  
Casting Method ◽  
Aluminium Matrix Composite ◽  
Effect Analysis ◽  
The Impact

AMC (Aluminium Matrix Composite) is material which has a great potential for being developed. This research was done to find effect added of Cu variation for impact strength and microstructure on Al-Si composite. Mass fractions of sand silika is 3% and Cu variation adding is 0, 1, 2, 3 & 4%. Composite manufacture is using stir casting method with stirring 600 rpm during of 5 minutes on semi solid temperature. Speciments were tested using optical microscope and impact charpy testing machine. The value impact of composite without adding Cu is 0,333 J/mm2 after added Cu value down. Until adding Cu 4% the value impact is 0,104 J/mm2. Micro photograph showed the result of porosity and SiO2 unform distribution with the adding of Cu to the composite. From the test results it is known that the strength of the impact decreases with mass fraction addition Cu. This is because the addition of Cu can increase the porosity and formed CuAl2 phase which are brittle.

scholarly journals Design of Rigid Pavement by Self Cured Concrete Utilizing Coarse Fly Ash Aggregates and Curing Admixture

2021 ◽  
Vol 889 (1) ◽  
pp. 012011
Author(s):  
Ajay Rana ◽  
Abhishek Sharma ◽  
Kshitij Jassal
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Power Plants ◽  
Thermal Power ◽  
Waste Product ◽  
Partial Replacement ◽  
Rigid Pavement ◽  
Natural Aggregates ◽  
The Impact ◽  
Ash Aggregates

Abstract In concrete industry, a huge amount of natural aggregates is used in the making of concrete every day. The environment is being exploited by mining for the gain of natural aggregates, resulting in an environmental instability in nature. As a result, an alternate source to substitute natural aggregates in concrete is required. A lot of waste materials have gain attention now a days into the concrete industry as a substitute to natural materials. Fly ash, a waste product of thermal power plants, meets the criterion for being utilised as an aggregate substitute in concrete because of its pozzolanic activity. Coarse fly ash is manufactured using a good manufacturing method and is light in weight. Keeping this into view, the impact of partial replacement of natural coarse aggregates with coarse fly ash aggregates produced using the colds bonded method is explored in this paper. The major focus of this study is on testing for flexural strength of self-cured concrete, as flexural strength is a key criterion for rigid pavement design. In this study, coarse fly ash aggregates are utilised in concrete in different proportions to substitute natural aggregates, and the optimal value for flexural strength is determined using a curing additive. The findings of this experiment indicated that when fly ash aggregates and curing additives were used optimally, the flexure strength improved, which is enough for the construction of rigid pavement as criteria fixed by Indian Standards.

The removal of As(V) ions by lime-modified fly ash and reuse of the exhausted adsorbent as an additive for construction material

2020 ◽  
Author(s):  
Milica Karanac ◽  
Maja Đolić ◽  
Vladimir Pavićević ◽  
Aleksandar Marinković
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Low Cost ◽  
Construction Material ◽  
Thermal Power ◽  
Construction Materials ◽  
Practical Applications ◽  
The Impact ◽  
By Products ◽  
Modified Fly Ash

<p>Coal thermal power plants (TPP) actively generate numerous solid combustion by-products, including fly ash and bottom ash. These TPP by-products have already found use in a variety of civil engineering applications, such as a substitute for sand and gravel in structures, as well as a binding component in certain types of cement (generally, concrete and masonry). Furthermore, such by-products have become a subject of increasing interest in environmental engineering as a low-cost and effective adsorbent for the removal of organic pollutants and heavy metals from wastewaters.</p><p>In order to minimize the impact of material cost, novel solutions for the development of a high capacity and long-term adsorbent have provided a high performance adsorbent for practical applications. This study is focused on the use of modified fly ash (MFA) activated by lime (Ca(OH)<sub>2</sub>) as an effective and low-cost adsorbent for the removal of As(V) ions. The adsorption capacity of the MFA adsorbent was found to be 35.40 mg g<sup>-1</sup>, while the kinetic and thermodynamic parameters indicated a spontaneous and endothermic process. Due to the low desorption potential of the exhausted adsorbent (MFA/As(V), their effective further material reuse was established to be feasible. The reuse of the exhausted adsorbent was obtained through pozzolanic MFA particles and Ca(OH)<sub>2, </sub>thereby formulating a construction material of a cementitious calcium-silicate hydrate. The toxicity leaching test (TCLP) and mechanical properties of the new construction material containing exhausted MFA (CM-MFA/As(V)) confirm its safe use in the laboratory as well as its semi-industrial application.</p><p>The specific objectives of this study have been: (i) to improve the adsorption performance of the MFA; (ii) to evaluate the material’s equilibrium, as well as the process’ kinetic and thermodynamic aspects, including  estimating its limiting step; and (iii) to investigate the possible reuse of the exhausted adsorbent in the production of construction materials. The kinetic data were successfully fitted by a pseudo-second-order equation and the Weber-Morris model. The metal-desorption experiments performed on the exhausted FA and MFA indicate a low recovery of the selected pollutants.</p><p>The major outcome of this study, indicates that double-valorization of fly ash opens new directions for waste management toward reuse in effective practical applications; i.e., for actual water –purification systems, as well as in the production of construction material.</p>

scholarly journals Production and Characterization of Porous Ceramics From Coal Fly Ash and Clay

2017 ◽  
Vol 14 (3-4) ◽  
Author(s):  
Biljana Angjusheva ◽  
Emilija Fidancevska ◽  
Vojo Jovanov
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Bending Strength ◽  
Coal Fly Ash ◽  
Porous Ceramic ◽  
Thermal Power ◽  
Construction Materials ◽  
Porous Ceramics ◽  
Significant Research ◽  
Different Content

The disposal of coal fly ash obtained in thermal power plants presents the general problem all over the world. Significant research on the utilization of fly ash has been carried out in the area of construction materials. The aim of this study was to develop porous ceramics based on coal fly ash and clay (60wt.%clay and 40wt.% fly ash). Three types of pore creators: two types of wood cutting (Quercus and Facus sylvatica) and C-powder were used for creating of the porous ceramics. The mixtures based on fly ash and clay and different content of pore creators (2, 5, 10 and 20wt.%) were consolidated (P=45 MPa, T = 900, 1000, 1050 and 1100oC/1h) to obtain porous ceramic (PC). The results indicate that the properties of the porous ceramics depend on the type and content of the pore creators. Furthermore, the sintering temperature was found to be main factor affecting the properties of the sintered products. The maximal bending strength (26 MPa) was achieved by using 2wt% P3 (C-powder) and the porous ceramics has the density and porosity of 1.90g/cm3 and 22%, respectively. By using the highest content (20wt.% ) of each pore creator (P1, P2 and P3) the lowest bending strength cca 5 MPa was achieved and the variation of the density and porosity was in the range from 1.22 to 1.32 g/cm3 and 44 to 48%, respectively. Water absorption, durability and the microstructure of the obtained porous ceramics are also reported in this paper.

Use of Specially Treated Hazardous Waste as Filler in Polymer Coatings

2021 ◽  
Vol 898 ◽  
pp. 49-55
Author(s):  
Tomáš Žlebek ◽  
Jakub Hodul ◽  
Rostislav Drochytka
Keyword(s):  
Fly Ash ◽  
Fluidized Bed ◽  
Hazardous Waste ◽  
Polymer Matrix ◽  
Surface Hardness ◽  
Optical Microscope ◽  
Polymer Coatings ◽  
Cement Kiln ◽  
Fluidized Bed Combustion ◽  
Polyurethane Resin

The objective of presented research was to verify and evaluate whether the treated hazardous waste (HW) can be used as filler in polymer coatings based on epoxy (EP) and polyurethane resin (PUR). The end product created by the incineration of municipal waste and cement dusts from cement kiln bypasses were chosen for solidification. The hazardous waste used was solidified by a homogenisation method using filter fly ash from fluidized bed combustion of lignite and silica flour as the solidifying agents. The aim was to use as much hazardous waste as possible and incorporate it into the polymer matrix of the coatings. The usability of the filler prepared in this way was verified by testing the tensile properties of polymer coatings, the surface hardness and the adhesion to the concrete. The cohesion of the coatings with concrete was observed using a digital optical microscope. It has been found that the PUR-based coatings with HW content show better properties than the coatings containing only the silica flour as a filler.

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