Visual Assessment for Detection of Diffusion Depth under External Sulfate Attack in Concrete

2021 ◽  
Vol 10 (1) ◽  
pp. 20200097
Author(s):  
Chiqian Ou ◽  
Zheng Chen ◽  
Chaofan Yi ◽  
Yaman Boluk ◽  
Vivek Bindiganavile
Keyword(s):  
Visual Assessment ◽  
Sulfate Attack ◽  
Diffusion Depth

Behaviors of Long-Term Exposure Concrete to Sulfate Solution

2011 ◽  
Vol 368-373 ◽  
pp. 790-794
Author(s):  
Shun Bo Zhao ◽  
Thomas C.K. Molyneaux ◽  
David W. Law ◽  
Yong Li ◽  
Li Yun Pan
Keyword(s):  
Compressive Strength ◽  
Sulfate Solution ◽  
Sulfate Attack ◽  
Sulfate Ions ◽  
Sulfate Solutions ◽  
Collaborative Studies ◽  
Diffusion Depth ◽  
One Year ◽  
The Uk

As a part of the collaborative studies between China, Australia and the UK, examing sulfate attack on concrete, this paper reports the experimental results obtained from the Chinese laboratory. Specimens were immersed in sodium and magnesium sulfate solutions with concentrations of 500mg/L, 5000mg/L and 50000mg/L. Investigations were conducted over approximately a one year period. Susceptibility to sulfate attack was assessed in terms of changes in the mass and length of specimens, the compressive strength of the concrete, as well as the diffusion depth of sulfate-ions into the concrete at fixed intervals. Several differences were observed between these results and those reported in studies from the UK laboratory.

scholarly journals Durability Performance of Binary and Ternary Blend Self Compacting Concrete using Waste Marble Powder and Lime Powder

2020 ◽  
Vol 9 (3) ◽  
pp. 402-409
Keyword(s):  
Strength Loss ◽  
Visual Assessment ◽  
Sulfate Attack ◽  
Ternary Blend ◽  
Acid Attack ◽  
Self Compacting Concrete ◽  
Marble Powder ◽  
High Concentrations ◽  
Lime Powder ◽  
Positive Results

Investigation practicing waste marble powder and lime powder as cement supplements in Self-compacting concrete (SCC) has obtained positive outcomes newly. In this research, waste marble powder (MW) and waste lime powder (LW) with the different combinations used in the design of SCC by replacement of cement 0, 10, 15 and 20%. In addition, 5% H2SO4 and 5% MgSO4 practiced for durability study and evaluate the effect of Sulfate attack and acid attack on filler content of mix after 28, 56, and 90 days curing of SCC sample. The results of the visual assessment and weight loss revealed that the increase in the amount of LW would enhance the performance of concrete, while the inclusion of LW and MW in SCC has shown positive results in terms of resistance against acid and sulfate attack. The mixtures with ternary binders of OPC, MW, and LW experienced the lowest strength loss after exposure to high concentrations of sulfate attack compared to unblended SCC.

scholarly journals Model for Sulfate Diffusion Depth in Concrete under Complex Aggressive Environments and Its Experimental Verification

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yingwu Zhou ◽  
Hao Tian ◽  
Hongzhi Cui ◽  
Feng Xing ◽  
Lili Sui
Keyword(s):  
Residual Life ◽  
Sulfate Attack ◽  
Time Varying ◽  
Complex Environments ◽  
Accelerated Corrosion ◽  
Diffusion Depth ◽  
Concrete Damage ◽  
Performance Deterioration ◽  
Accelerated Corrosion Test ◽  
First Time

Sulfate attack is one of the most important factors that lead to the performance deterioration of concrete materials. The progress of the sulfate diffusion depth in concrete is an important index that quantitatively characterizes the rate of concrete damage, cracking, and spalling due to sulfate attacks. The progress of the diffusion depth of concrete to sulfate attack is systematically investigated in this paper by both theoretical and experimental study. A newly time-varying model of the diffusion depth is developed, which has comprehensively considered a mass of parameter of complex environments for the first time. On this basis, a method is further proposed for effectively predicting the residual life of in-service concrete structures subject to sulfate attack. Integrating the data from the self-designed high-temperature dry-wet accelerated corrosion test and a large amount of experimental data reported in the existing literatures, the effectiveness and accuracy of the time-varying model of the diffusion depth by sulfates are finally verified.

The Effect of Chlorides on the Thaumasite Form of Sulfate Attack in Limestone Cement Concrete

2010 ◽  
Vol 636-637 ◽  
pp. 1349-1354
Author(s):  
K. Sotiriadis ◽  
E. Nikolopoulou ◽  
Sotiris Tsivilis
Keyword(s):  
Portland Cement ◽  
Chloride Content ◽  
Concrete Specimen ◽  
Visual Assessment ◽  
Xrd Analysis ◽  
Sulfate Attack ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Portland Limestone Cement ◽  
Limestone Cement

In this paper the effect of chlorides on the thaumasite form of sulfate attack in limestone cement concrete is studied. Concrete specimens made from ordinary Portland cement and two Portland limestone cements (limestone content 15% and 35% respectively) were prepared. After 28 days of curing the specimens were immersed in six solutions of various sulfate and chloride content and stored at 5oC. Visual assessment of the specimens, mass measurements and compressive strength tests took place for a period of 24 months. XRD method was used to identify thaumasite in the deteriorated parts of the specimens. All measurements showed that Portland cement concrete exhibits a lower degree of deterioration than Portland limestone cement concrete. Specimen disintegration was more severe, the higher the limestone contents of the cements and the higher the sulfate content of the corrosive storage solutions. Chlorides play an inhibitory role, delaying the deterioration of the concrete specimens. XRD analysis showed the presence of thaumasite at the deteriorated parts of the specimens after nine months of curing.

ROC Analysis of Three Perfusion Display Options for ECG-gated Perfusion SPECT in Severe CAD

1999 ◽  
Vol 38 (06) ◽  
pp. 172-177
Author(s):  
H. Bailer ◽  
Marianne Gwechenberger ◽  
Martha Pruckmayer ◽  
A. Staudenherz ◽  
G. Kronik ◽  
...  
Keyword(s):  
Roc Analysis ◽  
Lateral Wall ◽  
Visual Assessment ◽  
3D Mapping ◽  
Operating Characteristics ◽  
Gated Perfusion Spect ◽  
Perfusion Spect ◽  
Coronary Stenoses ◽  
Definition Of ◽  
Valve Plane

Summary Aim: The simultaneous computation and display of wall motion and perfusion patterns in a single 3D ventricular model would considerably ease the assessment of ECG-gated Tc-99m-sestamibi SPECT, yet the effect on the accuracy of allocating regional perfusion has so far not been validated. Methods: 3D perfusion mapping (3D Perfusion/Motion Map Software) was compared to the visual assessment of ungated tomographic slices and polar perfusion mapping (Cedars-Sinai PTQ) by correlation analysis and receiver operating characteristics (ROC) analysis at different cut-off levels for coronary stenoses in 50 patients (11 single-, 22 two-, 16 three-vessel disease). Ungated SPECT data were obtained by adding the intervals prior to reconstruction and displaying conventional tomographic slices. All display options were visually assessed in 8 ventricular segments according to a 4-point scoring system and compared to the graded results of coronary angiography. Results: All three display options showed a comparable diagnostic performance for the detection of severe stenoses. The diagnostic gain for the detection of stenoses above 59% was highest for ungated tomographic slices, followed by ungated polar mapping and 3D mapping. Regional assessment revealed a limited performance of 3D mapping in the proximal anterior and distal lateral wall. Polar mapping showed a balanced regional performance. Conclusion: 3D Perfusion mapping provides comparable information to conventional display options with the highest diagnostic strength in severe stenoses. Further improvement of the algorithm is needed in the definition of the valve plane.

A testing paradigm for quantifying ICC profilers

2019 ◽  
Vol 2019 (1) ◽  
pp. 80-85
Author(s):  
Pooshpanjan Roy Biswas ◽  
Alessandro Beltrami ◽  
Joan Saez Gomez
Keyword(s):  
Digital Camera ◽  
Visual Assessment ◽  
Just Noticeable Difference ◽  
Color Management ◽  
Color Gamut ◽  
Gamut Mapping ◽  
Digital File ◽  
Mapping Process ◽  
Testing Paradigm

To reproduce colors in one system which differs from another system in terms of the color gamut, it is necessary to use a color gamut mapping process. This color gamut mapping is a method to translate a specific color from a medium (screen, digital camera, scanner, digital file, etc) into another system having a difference in gamut volume. There are different rendering intent options defined by the International Color Consortium [5] to use the different reproduction goals of the user [19]. Any rendering intent used to reproduce colors, includes profile engine decisions to do it, i.e. looking for color accuracy, vivid colors or pleasing reproduction of images. Using the same decisions on different profile engines, the final visual output can look different (more than one Just Noticeable Difference[16]) depending on the profile engine used and the color algorithms that they implement. Profile performance substantially depends on the profiler engine used to create them. Different profilers provide the user with varying levels of liberty to design a profile for their color management needs and preference. The motivation of this study is to rank the performance of various market leading profiler engines on the basis of different metrics designed specifically to report the performance of particular aspects of these profiles. The study helped us take valuable decisions regarding profile performance without any visual assessment to decide on the best profiler engine.

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