From corrosion rate to accumulated corrosion depth or loss in cross section of reinforcements

2011 ◽  
pp. 43-51 ◽  
Author(s):  
Nuria Rebolledo ◽  
Carmen Andrade
Keyword(s):  
Corrosion Rate ◽  
Cross Section ◽  
Corrosion Depth

scholarly journals A Probabilistic Method for Estimating the Influence of Corrosion on the CuAlNi Shape Memory Alloy in Different Marine Environments

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 274
Author(s):  
Špiro Ivošević ◽  
Nataša Kovač ◽  
Gyöngyi Vastag ◽  
Peter Majerič ◽  
Rebeka Rudolf
Keyword(s):  
Shape Memory Alloy ◽  
Corrosion Rate ◽  
Shape Memory ◽  
Density Function ◽  
Statistical Tests ◽  
Ion Beam ◽  
Probabilistic Method ◽  
Random Variable ◽  
Marine Environments ◽  
Corrosion Depth

This paper gives an approach to the probabilistic percent corrosion depth estimation model for the CuAlNi Shape Memory Alloy (SMA) in different marine environments. Real testing was performed for validation of the theoretical model, where CuAlNi SMAs were exposed to 6 and 12 months in different seawater environments. Focus Ion Beam (FIB) analysis was used to measure the real corrosion depth on the surfaces of tested samples. A statistical approach to the investigation of the corrosion rate of CuAlNi SMA is given, where the corrosion rate is observed as a continuous random variable described by a linear corrosion model, with the assumption that corrosion starts immediately upon alloy surfaces being exposed to the influences of the marine environment. The three best-fitted two-parameter distributions for estimating the cumulative density function and the probability density function of the random variable were obtained by applying adequate statistical tests. Furthermore, using EDX analyses, we identified the chemical composition of the corroded materials, and with the help of Principal Component Analyses, we determined which corrosion environment had the most dominant influence on the corrosion process. The research results indicated that the changeable environment in the tides had a more heterogenic chemical content, which accelerated the corrosion rate.

scholarly journals Predicting Changes of the State of a Bridge Reinforced with Concrete Superstructures in View of Operational Changes

2019 ◽  
Vol 29 (3) ◽  
pp. 134-152
Author(s):  
Pavlo Ovchynnykov ◽  
Olha Dubinchyk ◽  
Oleksii Tiutkin ◽  
Vitalii Kildieiev ◽  
Volodymyr Sedin ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Service Life ◽  
Corrosion Rate ◽  
Crack Width ◽  
Laboratory Experiments ◽  
The State ◽  
Reinforcement Corrosion ◽  
Creep Theory ◽  
Corrosion Depth ◽  
Over Time

Abstract To solve the problem of predicting the service life of superstructures, this work proposes the basis and methodological developments of creep theory with increasing loads as well as regression analysis of the results of laboratory experiments. The main limitation in terms of reinforcement is corrosion in the concrete cracks, which was determined during laboratory experiments. Based on the results, the approximate analytical dependences concerning reinforcement corrosion depth change over time at a constant value of crack width were selected. The paper substantiates the validity of the analytical dependences as a result of regression analysis; it proposes formulae for determining the corrosion rate of rebars in reinforced concrete superstructures. The obtained analytical dependences allowed for the developing of a process for predicting changes to the state of the superstructure in light of operational changes.

Numerical Simulation of Corrosion under Different Solution Velocity

2008 ◽  
Vol 33-37 ◽  
pp. 1303-1306
Author(s):  
Hajime Adachi ◽  
Kazuhiro Suga ◽  
Masanori Hayase ◽  
Shigeru Aoki
Keyword(s):  
Numerical Simulation ◽  
Corrosion Rate ◽  
Cross Section ◽  
Laplace Equation ◽  
Tube Wall ◽  
Velocity Gradients ◽  
Velocity Effect ◽  
Volume Method ◽  
Solution Velocity ◽  
Derivatives Of

A numerical simulation of corrosion in a tube is performed with the solution velocity effect taken into account. A two dimensional tube, the cross-section of which is widening or narrowing with increase in distance, is considered. The velocity distribution in the tube is calculated with the Finite Volume Method (Open FOAM), and the derivatives of velocity with respect to the distance from the tube wall is determined at any location of the tube. The corrosion rate of the tube wall is estimated under the assumption that the corrosion rate depends on the velocity gradient, i.e. , it is estimated by solving the Laplace equation under the boundary conditions given with the polarization curves measured under various velocity gradients. The Boundary Element Method (3D-CAFE) is used to solve the Laplace equation. It is shown that the distribution of corrosion rate, including the maximum corrosion rate and its location, is different between the widening and narrowing tubes, even if the average velocities in the two tubes are equal.

Study on the Corrosion Behavior In Vitro and Mechanical Properties of the FHA Coated Mg-Zn-Zr Alloy

2016 ◽  
Vol 849 ◽  
pp. 647-653 ◽  
Author(s):  
C.G. Li ◽  
Min Fang Chen ◽  
S.Z. Sun ◽  
J. Zhang
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Treatment Method ◽  
Corrosion Depth ◽  
Significant Difference ◽  
Average Corrosion Rate ◽  
Zr Alloy

The fluorine-doped hydroxyapatite (FHA) coating on the surface of Mg-3wt%Zn-0.8wt%Zr alloy was prepared using a chemical treatment method. The standard tensile samples of coated and uncoated Mg alloy were immersed in the SBF respectively for 1,3,5,10,20 and 30 days. The effect of the FHA coating on corrosion behavior in vitro and mechanical properties of the Mg-Zn-Zr alloy was investigated. Based on the losing weight and the max corrosion depth of the samples, the corrosion rate can be calculated. According to the weightlessness curve of samples, the average corrosion rate of the bare alloy, the alloy of MgF2 coating and the alloy of FHA coating were 4.13mm / y, 1.51mm / y and 0.86mm / y within 30 days in vitro, respectively. It can be seen that the significant difference of mechanical properties between the coated and uncoated samples with the increase of immersing time. This fully revealed that the FHA coating on the Mg-Zn-Zr alloy is beneficial to improve its corrosion resistance.

Evaluating Section Loss in Corroded Steel Strands

2019 ◽  
Author(s):  
Yeun Chul Park ◽  
Chul-Hwan Yoo ◽  
Ho-Kyung Kim
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Box Girder ◽  
Corrosion Depth ◽  
Steel Wires ◽  
Corrosion Evaluation ◽  
Steel Strand ◽  
Corrosion Model ◽  
Typical Shape ◽  
Girder Bridge

<p>Since corrosion in prestressing tendon reduces the cross-section and strength of steel strand, it is critical for the safety of structures. Corrosion model in steel wires and a technique for evaluating section loss in steel strands were developed based on the measurement of corroded strands obtained from a concrete box girder bridge in Korea. The strands were corroded due to chloride and moisture attack. Cross-sections of corroded wires were measured for section loss, corrosion depth and perimeter. The measurement showed that corrosion rapidly progressed along the perimeter in earlier stage of corrosion, so that the shapes of remaining cross-sections were convex rather than concave which is typical shape of pitting corrosion. Evaluation of section loss in corroded steel strands were conducted using the wire corrosion model. If a strand can be approached from any direction around the strand, section loss could be evaluated within 5% of error.</p>

XUV Absorption Spectra of Carbon Ions

1988 ◽  
Vol 102 ◽  
pp. 71-73
Author(s):  
E. Jannitti ◽  
P. Nicolosi ◽  
G. Tondello
Keyword(s):  
Absorption Spectra ◽  
Cross Section ◽  
Theoretical Calculations ◽  
Photoionization Cross Section ◽  
Carbon Ions

AbstractThe photoabsorption spectra of the carbon ions have been obtained by using two laser-produced plasmas. The photoionization cross-section of the CV has been absolutely measured and the value at threshold, σ=(4.7±0.5) × 10−19cm2, as well as its behaviour at higher energies agrees quite well with the theoretical calculations.

Elastic Scattering in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 252-253
Author(s):  
J. Langmore ◽  
M. Isaacson ◽  
J. Wall ◽  
A. V. Crewe
Keyword(s):  
Electron Microscopy ◽  
Elastic Scattering ◽  
Cross Section ◽  
Quantum Noise ◽  
Dark Field ◽  
Elastic Cross Section ◽  
Biological Molecules ◽  
Dark Field Microscopy ◽  
Field Systems ◽  
Effects Of Radiation

High resolution dark field microscopy is becoming an important tool for the investigation of unstained and specifically stained biological molecules. Of primary consideration to the microscopist is the interpretation of image Intensities and the effects of radiation damage to the specimen. Ignoring inelastic scattering, the image intensity is directly related to the collected elastic scattering cross section, σɳ, which is the product of the total elastic cross section, σ and the eficiency of the microscope system at imaging these electrons, η. The number of potentially bond damaging events resulting from the beam exposure required to reduce the effect of quantum noise in the image to a given level is proportional to 1/η. We wish to compare η in three dark field systems.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

Freeze-Fracture Replication of Frozen Outer Segments of Rat Retinal Rods

1969 ◽  
Vol 27 ◽  
pp. 392-393
Author(s):  
Thomas S. Leeson ◽  
C. Roland Leeson
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Outer Segment ◽  
Freeze Fracture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Outer Segments ◽  
Retinal Rods ◽  
Temperature Electron ◽  
Freeze Etching

Numerous previous studies of outer segments of retinal receptors have demonstrated a complex internal structure of a series of transversely orientated membranous lamellae, discs, or saccules. In cones, these lamellae probably are invaginations of the covering plasma membrane. In rods, however, they appear to be isolated and separate discs although some authors report interconnections and some continuities with the surface near the base of the outer segment, i.e. toward the inner segment. In some species, variations have been reported, such as longitudinally orientated lamellae and lamellar whorls. In cross section, the discs or saccules show one or more incisures. The saccules probably contain photolabile pigment, with resulting potentials after dipole formation during bleaching of pigment. Continuity between the lamina of rod saccules and extracellular space may be necessary for the detection of dipoles, although such continuity usually is not found by electron microscopy. Particles on the membranes have been found by low angle X-ray diffraction, by low temperature electron microscopy and by freeze-etching techniques.

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