scholarly journals Fly Ash

2017 ◽  
Author(s):  
Anna Wilhelmsson
Keyword(s):  
Fly Ash ◽  
Environmental Protection Agency ◽  
High Water ◽  
Crushed Rock ◽  
Filling Materials ◽  
Dredged Materials ◽  
Land Disposal ◽  
Maintenance Dredging ◽  
Port Structures ◽  
New Framework

Over the next few years, more than one million m3 of contaminated sediments, with a muddy texture, high water ratio and low strength, shall be dredged annually in the development of ports and maintenance dredging of navigable waterways in Sweden. Dumping at sea is limited since the dredged materials are contaminated. Land disposal requires transports and land area and is thus high in costs. In the construction of new port areas, large volumes of crushed rock, etc. are normally used as construction filling materials. These materials can be replaced by stabilised and solidified dredged materials, with modified geotechnical properties. The method of stabilising / solidifying (s/s) contaminated dredged materials has been used internationally for a long period of time and in more recent years, even in the Nordic countries. In Sweden, for instance, the Port of Gävle and the Port of Oxelösund have received permissions to reuse s / s-treated contaminated dredged materials in the port structures. The Municipality of Oskarshamn have applied for permit and permission are expected in autumn 2012. The Municipality of Oskarshamn will receive funding from the Swedish Environmental Protection Agency for remediating the polluted sediments within the harbor basin. Reuse of the stabilized / solidified masses in a geotechnical structure is supported by the new Framework Directive (2008/98/EC) on waste where great emphasis is placed on recycling. Within some of the projects mentioned the potential of using fly ash as a complementary binder has been investigated. In the presentation some of the most interesting results will be presented.

Methods for simultaneous determination of 29 legacy and insensitive munition (IM) constituents in aqueous, soil-sediment, and tissue matrices by high-performance liquid chromatography (HPLC)

2021 ◽  
Author(s):  
Bobbi Stromer ◽  
Rebecca Crouch ◽  
Katrinka Wayne ◽  
Ashley Kimble ◽  
Jared Smith ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Solvent Extraction ◽  
Environmental Protection Agency ◽  
High Performance ◽  
Solid Phase ◽  
Degradation Products ◽  
Direct Injection ◽  
High Water ◽  
Hplc Method

Standard methods are in place for analysis of 17 legacy munitions compounds and one surrogate in water and soil matrices; however, several insensitive munition (IM) and degradation products are not part of these analytical procedures. This lack could lead to inaccurate determinations of munitions in environmental samples by either not measuring for IM compounds or using methods not designed for IM and other legacy compounds. This work seeks to continue expanding the list of target analytes currently included in the US Environmental Protection Agency (EPA) Method 8330B. This technical report presents three methods capable of detecting 29 legacy, IM, and degradation products in a single High Performance Liquid Chromatography (HPLC) method with either ultraviolet (UV)-visible absorbance detection or mass spectrometric detection. Procedures were developed from previously published works and include the addition of hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX); hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX); hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX); 2,4-diamino-6-nitrotoluene (2,4-DANT); and 2,6-diamino-4-nitrotoluene (2,6-DANT). One primary analytical method and two secondary (confirmation) methods were developed capable of detecting 29 analytes and two surrogates. Methods for high water concentrations (direct injection), low-level water concentrations (solid phase extraction), soil (solvent extraction), and tissue (solvent extraction) were tested for analyte recovery of the new compounds.

Mechanical Properties of Fly Ash–Asphalt Emulsion Geopolymer Stabilized Crushed Rock for Sustainable Pavement Base

2021 ◽  
Vol 33 (9) ◽  
pp. 04021220
Author(s):  
Teerasak Yaowarat ◽  
Wittakran Sudsaynate ◽  
Suksun Horpibulsuk ◽  
Avirut Chinkulkijniwat ◽  
Arul Arulrajah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Crushed Rock ◽  
Asphalt Emulsion ◽  
Pavement Base

scholarly journals Influential Factors in Transportation and Mechanical Properties of Aeolian Sand-Based Cemented Filling Material

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 116 ◽  
Author(s):  
Nan Zhou ◽  
Haobin Ma ◽  
Shenyang Ouyang ◽  
Deon Germain ◽  
Tao Hou
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Cement Content ◽  
Ash Content ◽  
Influential Factors ◽  
Filling Material ◽  
Aeolian Sand ◽  
Early Hydration ◽  
Filling Materials ◽  
Slag Content

Given that normal filling technology generally cannot be used for mining in the western part of China, as it has only a few sources for filling gangue, the feasibility of instead using cemented filling materials with aeolian sand as the aggregate is discussed in this study. We used laboratory tests to study how the fly ash (FA) content, cement content, lime–slag (LS) content, and concentration influence the transportation and mechanical properties of aeolian-sand-based cemented filling material. The internal microstructures and distributions of the elements in filled objects for curing times of 3 and 7 days are analyzed using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The experimental results show that: (i) the bleeding rate and slump of the filling-material slurry decrease gradually as the fly ash content, cement content, lime–slag content, and concentration increase, (ii) while the mechanical properties of the filled object increase. The optimal proportions for the aeolian sand-based cemented filling material include a concentration of 76%, a fly ash content of 47.5%, a cement content of 12.5%, a lime–slag content of 5%, and an aeolian sand content of 35%. The SEM observations show that the needle/rod-like ettringite (AFt) and amorphous and flocculent tobermorite (C-S-H) gel are the main early hydration products of a filled object with the above specific proportions. After increasing the curing time from 3 to 7 days, the AFt content decreases gradually, while the C-S-H content and the compactness increase.

scholarly journals Transformation of non-water sorbing fly ash to a water sorbing material for drought management

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abhisekh Saha ◽  
Sreedeep Sekharan ◽  
Uttam Manna ◽  
Lingaraj Sahoo
Keyword(s):  
Fly Ash ◽  
Plant Growth ◽  
Fine Sand ◽  
High Water ◽  
Drought Management ◽  
Soil Water Retention ◽  
Drought Period ◽  
Superabsorbent Hydrogel ◽  
Industrial Solid Waste ◽  
Agricultural Applications

Abstract Securing water in the soil through suitable amendments is one of the methods for drought management in arid regions. In this study, a poor water sorbing fly ash was transformed into a high water-absorbing material for improving soil water retention during the drought period. The fly ash water absorbent (FAWA) exhibited high water-absorbing capacity (WAC) of 310 g/g at par with commercially available superabsorbent hydrogel (SAH). The FAWA showed excellent re-swelling behavior for more than eight alternate wetting–drying cycles. The WAC of FAWA was sensitive to salt type, pH, and ionic strength of the solution. At maximum salinity level permitted for plant growth, the WAC of FAWA was 80 g/g indicating its suitability for drought management. There was only a marginal WAC variation in the range of pH (5.5–7.5) considered most suitable for plant growth. The drying characteristics of FAWA amended soil exhibited an increase in desaturation time by 3.3, 2.2, and 1.5 times for fine sand, silt loam, and clay loam, respectively. The study demonstrates the success of using a low rate of FAWA for drought management with the advantage of offering a non-toxic and eco-friendly solution to mass utilization of industrial solid waste for agricultural applications.

Research on the Application of Fly Ash in High Water Filling Material

2013 ◽  
Vol 807-809 ◽  
pp. 1124-1128
Author(s):  
Feng Yi Li ◽  
Lei Chen ◽  
Guang Qi Li ◽  
Wei Xin Chen ◽  
Peng Fei Wang
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
High Efficiency ◽  
High Water ◽  
Packing Material ◽  
Filling Material ◽  
Comprehensive Utilization ◽  
Push Forward ◽  
Water Filling ◽  
Utilization Ratio

Fly ash is a coal-fired waste from the coal-consumed power plant. It has become a great concern as to how fly ash should be treated properly at home. At present, the comprehensive utilization ratio of fly ash is just 30% and utilization ratio of fly ash from coal gangue power plant is less than coal-fired power plant. The effect of different fly ash added to the high-water filling material on the filling result was analyzed and field test of filling in mined-out area was conducted in the Babao vertical shaft + 3211 section of Tonghua coal mining group. The result shows that fly ash of gangue power plant added into the high-water packing material can lower the filling material cost effectively. This research can lead to push forward the utilization of fly ash with high efficiency.

Modeling the Effects of Fly Ash Characteristics and Mixture Proportions on Strength and Durability of Concretes

1986 ◽  
Vol 86 ◽  
Author(s):  
Elizabeth L. White ◽  
Della M. Roy ◽  
Philip D. Cady
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Common Factor ◽  
Load Condition ◽  
High Water ◽  
The United States ◽  
Type I ◽  
Modeling Tools ◽  
Strength Factor ◽  
Sulfate Resistance

ABSTRACTFactor analyses and cluster analyses were the modeling tools used to relate the chemical and physical characteristics of fly ash and cement to the strength, sulfate resistance, and freeze-thaw durability of fly ash-modified concrete. A Type I Portland cement was mixed with base load and upset load condition fly ashes from three different power plants in each of five regions in the United States. Based on the interactions between the reactive constittuents of the cement and fly ash, common factor loadings were identified. Cement loaded onto the early strength factor; fly ash loaded onto the later strength factor. In some subgroups the quantity of mixing liquid loaded separately as representative of the high water/cement ratio, which masked the reactive interactions between the fly ash and cement. In other subgroups the inter-relationships between sulfate resistance and strength with fly ash/cemment fineness, CaO content, and alkali content were represented in the factor analysis as well as in the numerical analysis models.

THE USE OF FLY ASH ALUMINOSILICATE MICROSPHERES IN THE LIME DRY MIXES FOR FINISHING AERATED CONCRETE

2017 ◽  
Vol 2 (3) ◽  
pp. 6-8 ◽  
Author(s):  
Логанина ◽  
Valentina Loganina ◽  
Фролов ◽  
Mikhail Frolov
Keyword(s):  
Thermal Conductivity ◽  
Water Vapor ◽  
Fly Ash ◽  
Water Vapor Permeability ◽  
High Water ◽  
Vapor Permeability ◽  
Low Thermal Conductivity ◽  
Aerated Concrete ◽  
Sufficient Strength

The application of ash microspheres in lime dry construction mixtures, designed for finishing aerated. It is shown that on the basis of dry ash mixtures with microspheres characterized by coating a sufficient strength, low thermal conductivity, high water vapor permeability, resistance to the action of the slanting rain.

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