Study of crushed stone-mastic asphalt concrete using fiber from fly ash of thermal power plants

Author(s):  
Andrii Bieliatynskyi ◽  
Shilin Yang ◽  
Valerii Pershakov ◽  
Meiyu Shao ◽  
Mingyang Ta
1999 ◽  
Vol 09 (03n04) ◽  
pp. 417-422 ◽  
Author(s):  
V. VIJAYAN ◽  
S. N. BEHERA

Fly ash is a major component of solid material generated by the coal-fired thermal power plants. In India the total amount of fly ash produced per annum is around 100 million tonnes. Fly ash has a great potential for utilization in making industrial products such as cement, bricks as well as building materials, besides being used as a soil conditioner and a provider of micro nutrients in agriculture. However, given the large amount of fly ash that accumulate at thermal power plants, their possible reuse and dispersion and mobilization into the environment of the various elements depend on climate, soils, indigenous vegetation and agriculture practices. Fly ash use in agriculture improved various physico-chemical properties of soil, particularly the water holding capacity, porosity and available plant nutrients. However it is generally apprehended that the application of large quantity of fly ash in fields may affect the plant growth and soil texture. Hence there is a need to characterize trace elements of fly ash. The results of trace element analysis of fly ash and pond ash samples collected from major thermal power plants of India by Particle Induced X-ray Emission (PIXE) have been discussed.


2021 ◽  
Vol 323 ◽  
pp. 8-13
Author(s):  
Jadambaa Temuujin ◽  
Damdinsuren Munkhtuvshin ◽  
Claus H. Ruescher

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.


Author(s):  
A. Kurlykina ◽  
V. Denisov ◽  
D. Kuznecov ◽  
E. Lukash

One of the main reasons for reducing the service life of road asphalt pavements (the appearance and development of damage in the form of ruts, various kinds of plastic deformations, potholes, cracks, etc.) is the low quality of the used oil bitumen. The physicomechanical properties of road bitumen are subject to stricter requirements, especially for organic binders used for the production of crushed stone mastic asphalt (SMA), therefore, in authors’ view, the development of bitumen binders with enhanced physicomechanical properties is one of the key and most urgent tasks in road construction. This problem is solved by introducing various modifiers into the binder. This article presents the results of a study of bitumen modified by introducing technical sulfur into the composition. The effect of binder modification on the physicomechanical properties of road asphalt concrete is shown on the example of crushed stone mastic asphalt (SMA-20) relative to base samples made to control the dynamics of changes in the properties of composites made using sulfur-raising technologies. For a comprehensive assessment of the effectiveness of modifying crushed stone mastic asphalt concrete based on various binders, a generalized quality criterion is calculated, taking into account the calculated particular quality criteria and various values of the weight coefficients. The comparison and analysis of the obtained efficiency criteria is made.


2021 ◽  
Vol 96 (4) ◽  
pp. 107-112
Author(s):  
YU.S. FILIMONOVA ◽  
◽  
E.G. VELICHKO ◽  

Modification of the composition and structure of heavy concrete with the use of a complex chemical-mineral additive consisting of fly ash from thermal power plants, a superplasticizer, a high-valence hardening accelerator AC and a fine-dispersed clinker component is considered. Modified concrete is characterized by an increase in compressive strength at a brand age by 67%, a decrease in the water content of a concrete mixture by 13.6% and an improvement in its workability by 11-12 cm. With the combined use of a superplasticizer and a high-valence hardening accelerator AC a significant synergistic effect is observed in the format of enhancing their plasticizing effect. The high efficiency of the application of the mixed-dispersed clinker component has been established.


2019 ◽  
Vol 9 (9) ◽  
pp. 1964 ◽  
Author(s):  
Dinh-Hieu Vu ◽  
Hoang-Bac Bui ◽  
Bahareh Kalantar ◽  
Xuan-Nam Bui ◽  
Dinh-An Nguyen ◽  
...  

Coal-fired power stations are one of the primary sources of power generation in the world. This will produce considerable amounts of fly ash from these power stations each year. To highlight the potential environmental hazards of these materials, this study is carried out to evaluate the characterization of fly ashes produced in thermal power plants in northern Vietnam. Fly ash was firstly fractionated according to size, and the fractions were characterized. Then, each of these fractions was analyzed with regard to their mineralogical features, morphological and physicochemical properties. The analytical results indicate a striking difference in terms of the characteristics of particles. It was found that magnetic fractions are composed of magnetite hematite and, to a lower rate, mullite, and quartz. Chemical analyses indicate that the non-magnetic components mainly consist of quartz and mullite as their primary mineral phases. As the main conclusion of this research, it is found that the magnetic and non-magnetic components differ in terms of shape, carbon content and mineralogical composition. In addition, it was found that magnetic components can be characterized as more spheroidal components compared to non-magnetic ones. This comprehensive characterization not only offers a certain guideline regarding the uses of different ash fractions but it will also provide valuable information on this common combustion process.


2018 ◽  
Vol 276 ◽  
pp. 110-115
Author(s):  
Martin Ťažký ◽  
Martin Labaj ◽  
Rudolf Hela

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.


2019 ◽  
Vol 23 (1) ◽  
pp. 50-54 ◽  
Author(s):  
A.I. Fomenko ◽  
L.I. Sokolov

The sorption characteristics of aluminosilicate microspheres of fly ash from thermal power plants with respect to heavy metal ions were studied with a view to their subsequent use for integrated treatment of household and industrial wastewater. The mechanism and kinetics of the sorption of total iron ions from aqueous solutions are studied, quantitative characteristics of the sorption capacity and adsorption equilibrium constants are obtained. It has been established that aluminosilicate microspheres of fly ash possess sorption properties with respect to common iron ions. The sorption isotherm of iron ions from water by the material under study is characteristic of microporous sorbents. The quantitative characteristics of the sorption process allow us to conclude about the possibility of using aluminosilicate fly ash microspheres without any additional treatment for the purification of waste water from heavy metal ions.


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