Electrochemical Stability of Embedded Steel and Toxic Elements in Fly Ash/Cement Beds

1986 ◽  
Vol 86 ◽  
Author(s):  
R. I. A. Malek ◽  
D. M. Roy
Keyword(s):  
Fly Ash ◽  
Toxic Elements ◽  
Construction Materials ◽  
Leach Solution ◽  
Electrochemical Stability ◽  
Field Conditions ◽  
Redox Potentials ◽  
Electrochemical Stabilities ◽  
The Matrix ◽  
Regions Of Stability

ABSTRACTThe electrochemical stability in fly ash/cement beds is of major concern to the durability of construction metals (iron or steel) embedded in the matrix as well as the stabilization (fixation) of toxic elements. The electrochemical stabilities were evaluated by measuring the redox potential as a function of both time and leach solution. For simulating the field conditions, the measurements were made on leachates of a prepared solution simulating rain composition in the area of application and results were contrasted to those obtained on leachates of standard deionized water. Two leaching techniques were used: the standard EPA-EP test; a test developed at MRL/PSU for simulating field conditions in which leaching fluids are pumped up a fly ash/cement column. The redox potentials (based on hydrogen scale), Eh's, were plotted vs. pH of the leachates and the regions of stability of various construction materials and toxic elements were predicted. Tafel plots were also constructed for iron in contact with different leachates, and its corrosion rate was estimated.

scholarly journals Utilization of Brine Sludge in Nonstructural Building Components: A Sustainable Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Mridul Garg ◽  
Aakanksha Pundir
Keyword(s):  
Fly Ash ◽  
Construction Materials ◽  
Alternative Solution ◽  
Engineering Properties ◽  
Reaction Products ◽  
The Matrix ◽  
Building Components ◽  
Waste Particles ◽  
Brine Sludge ◽  
Nonstructural Building Components

The characterization and influence of brine sludge on the properties of cement-fly ash-sludge binders are presented. The reaction products formed during the hydration of binder provide an interlocking framework to physically encapsulate the waste particles and are responsible for the development of strength. The utilization of brine sludge in making paver blocks and bricks and the effect of sludge concentration on the engineering properties of these products are also discussed. These results clearly exhibited that brine sludge up to 35 and 25% can safely be utilized for making paver blocks and bricks, respectively. The leachability studies confirm that the metals ions and impurities in the sludge are substantially fixed in the matrix and do not readily leach from there. The utilization of brine sludge in construction materials could serve as an alternative solution to disposal and reduce pollution.

scholarly journals ELECTRICAL PROPERTIES OF FLY ASH GEOPOLYMER COMPOSITES WITH GRAPHITE CONDUCTIVE ADMIXTURES

2019 ◽  
Vol 22 ◽  
pp. 72-76 ◽  
Author(s):  
Celílie Mizerová ◽  
Ivo Kusák ◽  
Pavel Rovnaník
Keyword(s):  
Fly Ash ◽  
Electrical Properties ◽  
Health Monitoring ◽  
Construction Materials ◽  
Graphite Powder ◽  
Traffic Monitoring ◽  
The Matrix ◽  
Matrix Resistance ◽  
Alkali Activated ◽  
Geopolymer Composites

Construction materials with increased electrical conductivity could be possibly used in health monitoring of structures (stress, deformation, damages), their maintenance or traffic monitoring. The aim of this study was the application of functional filler and its influence on the electrical properties of the alkali-activated fly ash matrix. The graphite powder was added to the reference material in the amount of 2–10 %. Besides the assessment of the critical amount of filler necessary to achieve a percolation threshold in the structure of the composite, the effect on the electrical properties of the matrix (resistance, capacitance, conductivity) was determined. The optimal amount of filler was also determined with respect to the changes in microstructure of the binder and its mechanical properties.

scholarly journals The Influence of Mixing Methods of Epoxy Composition Ingredients on Selected Mechanical Properties of Modified Epoxy Construction Materials

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 411
Author(s):  
Izabela Miturska ◽  
Anna Rudawska ◽  
Miroslav Müller ◽  
Monika Hromasová
Keyword(s):  
Tensile Strength ◽  
Epoxy Resin ◽  
Construction Materials ◽  
Preliminary Heating ◽  
Epoxy Composition ◽  
Mixing Speed ◽  
Adhesive Composition ◽  
Adhesive Compositions ◽  
The Matrix ◽  
Level Of Significance

The proper process of preparing an adhesive composition has a significant impact on the degree of dispersion of the composition ingredients in the matrix, as well as on the degree of aeration of the resulting composition, which in turn directly affects the strength and functional properties of the obtained adhesive compositions. The paper presents the results of tensile strength tests and SEM microphotographs of the adhesive composition of Epidian 57 epoxy resin with Z-1 curing agent, which was modified using three fillers NanoBent ZR2 montmorillonite, CaCO3 calcium carbonate and CWZ-22 active carbon. For comparison purposes, samples made of unmodified composition were also tested. The compositions were prepared with the use of six mixing methods, with variable parameters such as type of mixer arm, deaeration and epoxy resin temperature. Then, three mixing speeds were applied: 460, 1170 and 2500 rpm. The analyses of the obtained results showed that the most effective tensile results were obtained in the case of mixing with the use of a dispersing disc mixer with preliminary heating of the epoxy resin to 50 °C and deaeration of the composition during mixing. The highest tensile strength of adhesive compositions was obtained at the highest mixing speed; however, the best repeatability of the results was observed at 1170 rpm mixing speed. Based on a comparison test of average values, it was observed that, in case of modified compositions, the values of average tensile strength obtained at mixing speeds at 1170 and 2500 rpm do not differ significantly with the assumed level of significance α = 0.05.

scholarly journals Hemp Fiber Reinforced Red Mud/Fly Ash Geopolymer Composite Materials: Effect of Fiber Content on Mechanical Strength

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 511 ◽  
Author(s):  
Eyerusalem A. Taye ◽  
Judith A. Roether ◽  
Dirk W. Schubert ◽  
Daniel T. Redda ◽  
Aldo R. Boccaccini
Keyword(s):  
Fly Ash ◽  
Mechanical Strength ◽  
Red Mud ◽  
Fiber Reinforced ◽  
Brazilian Tensile Strength ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
The Matrix ◽  
Geopolymer Composites ◽  
Scanning Electron

Novel hemp fiber reinforced geopolymer composites were fabricated. The matrix was a new geopolymer based on a mixture of red mud and fly ash. Chopped, randomly oriented hemp fibers were used as reinforcement. The mechanical properties of the geopolymer composite, such as diametral tensile (DTS) (or Brazilian tensile) strength and compressive strength (CS), were measured. The geopolymer composites reinforced with 9 vol.% and 3 vol.% hemp fiber yielded average DTS values of 5.5 MPa and average CS values of 40 MPa. Scanning electron microscopy (SEM) studies were carried out to evaluate the microstructure and fracture surfaces of the composites. The results indicated that the addition of hemp fiber is a promising approach to improve the mechanical strength as well as to modify the failure mechanism of the geopolymer, which changed from brittle to “pseudo-ductile”.

Alternative Concrete – Geopolymer Concrete

2021 ◽  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Construction Industry ◽  
Building Material ◽  
Construction Materials ◽  
Raw Material ◽  
Geopolymer Concrete ◽  
Sustainable Solutions ◽  
New Construction ◽  
Alkali Activated

Concrete is the most versatile, durable and reliable material and is the most used building material. It requires large amounts of Portland cement which has environmental problems associated with its production. Hence, an alternative concrete – geopolymer concrete is needed. The general aim of this book is to make significant contributions in understanding and deciphering the mechanisms of the realization of the alkali-activated fly ash-based geopolymer concrete and, at the same time, to present the main characteristics of the materials, components, as well as the influence that they have on the performance of the mechanical properties of the concrete. The book deals with in-depth research of the potential recovery of fly ash and using it as a raw material for the development of new construction materials, offering sustainable solutions to the construction industry.

scholarly journals Treatment of Soil Contaminated by Mining Activities to Prevent Contamination by Encapsulation in Ceramic Construction Materials

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6740
Author(s):  
Juan María Terrones-Saeta ◽  
Jorge Suárez-Macías ◽  
Antonio Bernardo-Sánchez ◽  
Laura Álvarez de Prado ◽  
Marta Menéndez Fernández ◽  
...  
Keyword(s):  
Ceramic Material ◽  
Contaminated Soil ◽  
Toxic Elements ◽  
Construction Materials ◽  
Well Being ◽  
Ceramic Materials ◽  
Potentially Toxic Elements ◽  
Raw Material ◽  
Mining District ◽  
Different Soils

Mining is an essential activity for obtaining materials necessary for the well-being and development of society. However, this activity produces important environmental impacts that must be controlled. More specifically, there are different soils near new or abandoned mining productions that have been contaminated with potentially toxic elements, and currently represent an important environmental problem. In this research, a contaminated soil from the mining district of Linares was studied for its use as a raw material for the conforming of ceramic materials, bricks, dedicated to construction. Firstly, the contaminated soil was chemically and physically characterized in order to evaluate its suitability. Subsequently, different families of samples were conformed with different percentages of clay and contaminated soil. Finally, the conformed ceramics were physically and mechanically characterized to examine the variation produced in the ceramic material by the incorporation of the contaminated soil. In addition, in this research, leachate tests were performed according to the TCLP method determining whether encapsulation of potentially toxic elements in the soil occurs. The results showed that all families of ceramic materials have acceptable physical properties, with a soil percentage of less than 80% being acceptable to obtain adequate mechanical properties and a maximum of 70% of contaminated soil to obtain acceptable leachate according to EPA regulations. Therefore, the maximum percentage of contaminated soil that can be incorporated into the ceramic material is 70% in order to comply with all standards. Consequently, this research not only avoids the contamination that contaminated soil can produce, but also valorizes this element as a raw material for new materials, avoiding the extraction of clay and reducing the environmental impact.

scholarly journals Partial Replacement of Cement by Neem Leaves Ash and Fly Ash

2020 ◽  
Vol 9 (1) ◽  
pp. 506-508
Keyword(s):  
Experimental Investigation ◽  
Fly Ash ◽  
Ordinary Portland Cement ◽  
Construction Materials ◽  
Strength Properties ◽  
Vital Role ◽  
Partial Replacement ◽  
Cement Ratio ◽  
Neem Leaves ◽  
The World

Concrete is the most essential construction materials in all over the world. It is necessary to search the cheaply obtainable material as admixture which might be partially replaced cement in the production of concrete. This project is an experimental investigation of the neem leaves ash as partial replacement for cement also fly ash is used for partial replacement of cement. The neem leaves were dried, burnt and heated in the furnace to produce Neem leaves Ash, which was discovered to posses Pozzolanic properties.the ordinary Portland cement was replaced by neem ash by 5%,10%,15%,20% and 25% by weight also flash replaced by 15%,20%,25% and 30% the cubes were crushed to know the comparative strength of the concrete at different curing days. The last result showed that workability and strength properties of the concrete was depended on water cement ratio, total days of curing, the percentage of replacement of Neem leaves ash for OPC . I. This project it was noticed that the result of 5% NLA and 15% fly ash and 10% NLA and 20% of fly ash were gradually increasing the strength at 28 days. Neem leaves play a vital role and behaviour of Neem leaves ash and flash used concrete will be studied

Fabrication and Characterization of A356-Basalt Ash-Fly Ash Composites Processed by Stir Casting Method

2017 ◽  
Vol 25 (3) ◽  
pp. 209-214 ◽  
Author(s):  
G. Venkatachalam ◽  
A. Kumaravel
Keyword(s):  
Fly Ash ◽  
Impact Strength ◽  
Hybrid Composites ◽  
Cost Effective ◽  
Weight Fraction ◽  
Stir Casting ◽  
Matrix Composites ◽  
Casting Method ◽  
The Matrix

This paper presents the characterization of A356 composite reinforced with fly ash and basalt ash produced by stir casting method. Aluminium metal matrix composites (AMC) are used in wide variety of applications such as structural, aerospace, marine, automotive etc. Stir casting is cost effective manufacturing process and it is useful to enhance the attractive properties of AMCs. Three sets of hybrid AMC are prepared by varying the weight fraction of the reinforcements (3% basalt + 7% fly ash, 5% basalt + 5% fly, 7% basalt + 3% fly ash). The effect of reinforcements on the mechanical properties of the hybrid composites such as hardness, tensile, compressive and impact strength were studied. The obtained results reveal that tensile, compressive and impact strength was increased when weight fraction of fly ash increased, whereas the hardness increases when weight fraction of the basalt ash increased. Microscopic study reveals the dispersion of the reinforcements in the matrix.

scholarly journals Heat treatment effect on metal matrix composite with brass matrix and fly ash

2018 ◽  
Vol 204 ◽  
pp. 05020
Author(s):  
Aminnudin Aminnudin ◽  
Moch. Agus Choiron
Keyword(s):  
Heat Treatment ◽  
Fly Ash ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Coal Combustion ◽  
Metal Matrix ◽  
Treatment Process ◽  
Impact Test ◽  
Test Results ◽  
The Matrix

Metal matrix composite (MMC) is a combination of two or more materials using metal as a matrix. In this paper we used brass as the matrix and fly ash as for the particle. The fly ash used is fly ash which is produced from coal combustion in the Paiton power plant. Fly ash composition in the MMC are 5% and 10%. The MMC was produced with gas furnace. Heat tratment to MMC was done at 350 and 400 °C.Hard testing process, tensile test and impack test are carried out at MMC before heat treatment and after heat treatment. From the test results showed an increase in hardness, tensile strength and impact test showed the heat treatment process at a temperature of 350 °C. Heat treatment at a temperature of 400 °C does not improve the mechanical properties of MMC

Sign in / Sign up

Export Citation Format

Share Document