scholarly journals Wetting-Drying Resistance of a Lime Stabilized Soil Amended with Steel Slag and Reinforced with Fibres

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Jijo James ◽  
Alex Kirubhakaran ◽  
R. Balamurukan ◽  
V. Jawahar ◽  
S.S. Soorya
Keyword(s):  
Steel Slag ◽  
Expansive Soil ◽  
Reinforced Soil ◽  
Specimen Preparation ◽  
Polypropylene Fibres ◽  
Wetting And Drying ◽  
Stabilized Soil ◽  
Filament Content

The investigation dealt with the stabilization of expansive soil with combinations of lime, steel slag and reinforced with two types of fibres, copper filaments and polypropylene fibres. The investigation began with the characterization of the soil for its geotechnical properties. The initial consumption of lime required for the modification of the soil properties was determined from the Eades and Grim pH test. Cylindrical specimens of soil with dimensions 38 mm x 76 mm were cast using this lime content as a stabilizer along with varying quantities of steel slag for determination of optimum steel slag content. The pure lime stabilized soil as well as lime-steel slag modified soil specimens were reinforced with different proportions of copper filaments for determination of optimum fibre content. One dosage of polypropylene fibres was also adopted as reinforcement in specimen preparation. The optimal combinations identified were then subjected to a maximum of three cycles of wetting and drying followed by determination of unconfined compression strength (UCS). The expansive soil required a minimum of 3% lime for its modification. The optimum dosage of steel slag was identified as 5% and optimum copper filament content as 1%. Polypropylene content of 0.3% was also adopted as one combination. The results of the investigation revealed that lime stabilized fibre-reinforced soil with copper filaments was the most durable combination followed by polypropylene fibres. The introduction of steel slag in the mix could not generate enough beneficial durability to the soil after three cycles of wetting and drying.

scholarly journals Valorisation of egg shell ash as a potential replacement for lime in stabilization of expansive soils

2020 ◽  
Vol 63 (3) ◽  
pp. 13-20
Author(s):  
Jijo James ◽  
Priya Jothi ◽  
P. Karthika ◽  
S. Kokila ◽  
V. Vidyasagar
Keyword(s):  
Soil Properties ◽  
Soil Stabilization ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Wetting And Drying ◽  
Lime Content ◽  
Stabilized Soil ◽  
Egg Shell

The investigation focussed on the possibility of replacing lime in soil stabilization using Egg Shell Ash (ESA), a waste derived from poultry industry. An expansive soil was characterized for its properties in the lab. The minimum lime content required for modification of soil properties was determined from the Eades and Grim pH test. This lime content came out to be 3%. The lime content was replaced using ESA in the proportions of 33%, 50%, 67% and 100%. Unconfined compression test specimens of dimension 38 mm x 76 mm were cast for different combinations and were cured for periods of 3, 7 and 28 days. Samples were also subjected to 1, 3 and 5 cycles of wetting and drying to understand its durability. After the designated curing periods and cycles of wetting and drying, they were strained axially till failure. Atterberg limits tests were done to determine the plasticity of the stabilized soil. The strength results indicated that ESA cannot be used under normal conditions as a replacement for lime, however, ESA replacement resulted in good durability of the specimens under conditions of wetting and drying. It was concluded that ESA replacement of lime can be adopted in conditions of wetting and drying.

scholarly journals Potential of Portland pozzolana cement in the stabilization of an expansive soil subjected to alternate cycles of wetting and drying

2021 ◽  
Vol 64 (2) ◽  
pp. 81-91
Author(s):  
Jijo James ◽  
Anupriya Natesan ◽  
Aswini Manohar ◽  
Vishvaa Subramanian
Keyword(s):  
Blended Cement ◽  
Expansive Soil ◽  
Industrial Wastes ◽  
Wetting And Drying ◽  
Stabilized Soil ◽  
Ucs Test ◽  
The Common ◽  
Portland Pozzolana Cement ◽  
Better Than

Cement/lime stabilization of soils is one of the common techniques adopted for improving its geotechnical properties. Lately, the focus of investigation has shifted to blended stabilization with industrial wastes as auxiliary additives. However, the role of blended cement in stabilization of soil has been studied insufficiently despite the fact that it is manufactured under controlled conditions. This investigation deals with the use of Portland pozzolana cement (PPC) instead of ordinary Portland cement (OPC) in the stabilization of an expansive soil subjected to alternate cycles of wetting and drying. Unconfined compression strength (UCS) test specimens of dimensions 38mm x 76mm were cast and cured for periods of 7, 14 and 21 days. Then, the specimens were subjected to 1, 2 and 3 cycles of wetting and drying and the UCS of the specimens were determined. Based on the results of the investigation, it was found that OPC performed significantly better than PPC under normal conditions. However, under conditions of wetting and drying, PPC stabilized soil performed much better than OPC stabilized soil when sufficient binder content was available.

scholarly journals Effect of Curing Conditions and Freeze-Thaw Cycles on the Strength of an Expansive Soil Stabilized with a Combination of Lime, Jaggery, and Gallnut Powder

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jijo James ◽  
S. Karthickeyan ◽  
S. Chidambaram ◽  
B. Dayanandan ◽  
K. Karthick
Keyword(s):  
South India ◽  
Expansive Soil ◽  
Strength Loss ◽  
Reaction Products ◽  
Unconfined Compression ◽  
Curing Conditions ◽  
Freeze Thaw ◽  
Stabilized Soil ◽  
Materials Used

This investigation involved the utilization of the combination of lime, jaggery, and gallnut powder, adopted in South India traditionally. This combination of materials, used for the manufacture of lime-based mortars, was adopted in stabilization of an expansive soil. Three combinations of lime, jaggery, and gallnut powder (LJG) in the ratios of 8 : 2 : 2, 8 : 2 : 1, and 8 : 1 : 2 were put into use. The effect of subjecting the combinations to alternate cycles of freeze-thaw (up to 3 cycles) and three different curing conditions of air, moisture, and heat was also investigated. In addition, a mineralogical investigation for studying the reaction products was also carried out. The investigation proceeded with the determination of the unconfined compression strength (UCS) of stabilized specimens of dimensions 38 mm × 76 mm, cured for periods of 3, 7, 14, and 28 days. The results of the investigation revealed that the addition of LJG resulted in an increase in the strength of the stabilized soil. Freeze-thaw cycles resulted in a reduction in strength with LJG821 proving to be the most optimal combination developing the maximum strength and least strength loss due to freeze-thaw cycles. Thermal curing proved to be the most optimal curing condition out of all curing conditions evaluated.

Actin filament content in platelets—A sensitive index of cellular reactivity

1989 ◽  
Vol 9 (3) ◽  
pp. 307-313 ◽  
Author(s):  
P. Spangenberg ◽  
U. Till
Keyword(s):  
Actin Filament ◽  
Blood Platelets ◽  
Surface Membrane ◽  
Membrane Glycoproteins ◽  
Function Tests ◽  
Sensitive Function ◽  
Filament Content

Blood platelets have the capacity to participate in a number of physiological as well as pathological processes within the circulation. In order to evaluate their cellular reactivity a number of platelet function tests have been developed. The main in vitro function tests are assessment of aggregation and adhesion, secretion, arachidonate metabolism, coagulant activities and the characterization of surface membrane glycoproteins (Day and Rao, 1986). Here we measure alterations of the G-/F-actin equilibrium of platelets. High F-actin values of unstimulated platelets indicate a hyperreactivity of the cell as examined in platelets from diabetics. Determination of the actin filament content in platelets can be considered as a new sensitive function test.

Atom-Probe-Tomographic Studies on Silicon-Based Semiconductor Devices

2012 ◽  
Vol 20 (5) ◽  
pp. 38-44 ◽  
Author(s):  
Koji Inoue ◽  
Ajay Kumar Kambham ◽  
Dominique Mangelinck ◽  
Dan Lawrence ◽  
David J. Larson
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Semiconductor Devices ◽  
High Sensitivity ◽  
Atom Probe ◽  
Atomic Scale ◽  
Specimen Preparation ◽  
Silicon Based

The development of laser-assisted atom probe tomography (APT) and specimen preparation techniques using a focused ion beam equipped with high-resolution scanning electron microscopy (SEM) has significantly advanced the characterization of semiconductor devices by APT. The capability of APT to map out elements in devices at the atomic scale with high sensitivity meets the characterization requirements of semiconductor devices such as the determination of elemental distributions for each device region.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Preparation and characterization of thin films of carbon nitride

1995 ◽  
Vol 53 ◽  
pp. 104-105
Author(s):  
L. Wan ◽  
R. F. Egerton
Keyword(s):  
Carbon Nitride ◽  
Arc Discharge ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Reactive Sputtering ◽  
Vacuum Arc ◽  
Specimen Preparation ◽  
Bonding Structure ◽  
Electron Energy Loss

INTRODUCTION Recently, a new compound carbon nitride (CNx) has captured the attention of materials scientists, resulting from the prediction of a metastable crystal structure β-C3N4. Calculations showed that the mechanical properties of β-C3N4 are close to those of diamond. Various methods, including high pressure synthesis, ion beam deposition, chemical vapor deposition, plasma enhanced evaporation, and reactive sputtering, have been used in an attempt to make this compound. In this paper, we present the results of electron energy loss spectroscopy (EELS) analysis of composition and bonding structure of CNX films deposited by two different methods.SPECIMEN PREPARATION Specimens were prepared by arc-discharge evaporation and reactive sputtering. The apparatus for evaporation is similar to the traditional setup of vacuum arc-discharge evaporation, but working in a 0.05 torr ambient of nitrogen or ammonia. A bias was applied between the carbon source and the substrate in order to generate more ions and electrons and change their energy. During deposition, this bias causes a secondary discharge between the source and the substrate.

High-resolution microscopy of twin boundaries in gold

1987 ◽  
Vol 45 ◽  
pp. 260-261
Author(s):  
William Krakow ◽  
David A. Smith
Keyword(s):  
High Resolution ◽  
Specimen Preparation ◽  
Gold Films ◽  
Boundary Area ◽  
Transmission Electron ◽  
Recent Developments ◽  
Tilt Boundaries ◽  
High Resolution Microscopy ◽  
Twist Boundaries

Recent developments in specimen preparation, imaging and image analysis together permit the experimental determination of the atomic structure of certain, simple grain boundaries in metals such as gold. Single crystal, ∼125Å thick, (110) oriented gold films are vapor deposited onto ∼3000Å of epitaxial silver on (110) oriented cut and polished rock salt substrates. Bicrystal gold films are then made by first removing the silver coated substrate and placing in contact two suitably misoriented pieces of the gold film on a gold grid. Controlled heating in a hot stage first produces twist boundaries which then migrate, so reducing the grain boundary area, to give mixed boundaries and finally tilt boundaries perpendicular to the foil. These specimens are well suited to investigation by high resolution transmission electron microscopy.

Applications of ultramicrotomy for materials characterization

1993 ◽  
Vol 51 ◽  
pp. 232-233
Author(s):  
R.T. Blackham ◽  
J.J. Haugh ◽  
C.W. Hughes ◽  
M.G. Burke
Keyword(s):  
Materials Science ◽  
Microstructural Analysis ◽  
Analytical Electron Microscopy ◽  
Austenitic Stainless Steels ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Thermally Induced ◽  
Radiation Induced ◽  
Characterization Of Materials

Essential to the characterization of materials using analytical electron microscopy (AEM) techniques is the specimen itself. Without suitable samples, detailed microstructural analysis is not possible. Ultramicrotomy, or diamond knife sectioning, is a well-known mechanical specimen preparation technique which has been gaining attention in the materials science area. Malis and co-workers and Glanvill have demonstrated the usefulness and applicability of this technique to the study of a wide variety of materials including Al alloys, composites, and semiconductors. Ultramicrotomed specimens have uniform thickness with relatively large electron-transparent areas which are suitable for AEM anaysis.Interface Analysis in Type 316 Austenitic Stainless Steel: STEM-EDS microanalysis of grain boundaries in austenitic stainless steels provides important information concerning the development of Cr-depleted zones which accompany M23C6 precipitation, and documentation of radiation induced segregation (RIS). Conventional methods of TEM sample preparation are suitable for the evaluation of thermally induced segregation, but neutron irradiated samples present a variety of problems in both the preparation and in the AEM analysis, in addition to the handling hazard.

Characterization of Impressed Current Technique to Model Corrosion of Reinforcement in Concrete

2020 ◽  
Vol 11 (1) ◽  
pp. 93-99
Author(s):  
Abu Zakir Morshed ◽  
Sheikh Shakib ◽  
Tanzim Jahin
Keyword(s):  
Immersion Time ◽  
Chloride Content ◽  
Engineering Science ◽  
Coastal Regions ◽  
Faraday’S Law ◽  
Current Technique ◽  
Corrosion Cell ◽  
Impressed Current

Corrosion of reinforcement is an important durability concern for the structures exposed to coastal regions. Since corrosion of reinforcement involves long periods of time, impressed current technique is usually used to accelerate the corrosion of reinforcement in laboratories. Characterization of impressed current technique was the main focus of this research,which involved determination of optimum chloride content and minimum immersion time of specimens for which the application of Faraday’s law could be efficient. To obtain optimum chloride content, the electrolytes in the corrosion cell were prepared similar to that of concrete pore solutions. Concrete prisms of 200 mm by 200 mm by 300 mm were used to determine the minimum immersion time for saturation. It was found that the optimum chloride content was 35 gm/L and the minimum immersion time for saturation was 140 hours. Accounting the results, a modified expression based on Faraday’s law was proposed to calculate weight loss due to corrosion. Journal of Engineering Science 11(1), 2020, 93-99

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