scholarly journals Relating Corroded Seven-Strand, Posttensioned Cable Cross-Sectional Properties to Load Capacity

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Richard Haskins ◽  
Barry White ◽  
Robert Ebeling ◽  
James Evans
Keyword(s):  
Load Capacity ◽  
Short Axis ◽  
Cross Sectional ◽  
Accelerated Corrosion ◽  
Test Dataset ◽  
Linear Rate ◽  
Optical Scanning ◽  
Corrosion Loss ◽  
Optical Scan ◽  
Pull Tests

Multistrand anchors have seen widespread use, providing strength and stability at hydraulic Corps facilities. However, these steel tendons are subject to strength reduction as an effect of corrosion. Methods for evaluating the corroded cable strength do not exist to accurately estimate the time until tendon cables would have to be replaced (at great expense). The following five research tasks are used to address this deficiency: laboratory accelerated corrosion; pull-tests on pristine and laboratory corroded cables; optical scanning; data collection correlated with cross-sectional properties of cables; and development of a method to relate this data to the field. The pull-tests provide measured capacities for seven-strand, posttensioned (PT) cables. An optical scan of the corroded cables provides cross-sectional properties of individual wires within the pulled cables. Trendlines are established for the related peak cable capacities and cross-sectional properties in an effort to determine their correlations. Trendlines for minimum wire area and second-moment short axis diameter are found with low error, making them good predictors of loaded cable capacity. This pull-test dataset has been related back to cable failure in the field, assuming a linear rate of corrosion loss for the cross-sectional properties and required PT capacity.

Distribution and Characteristics of Intrathoracic Lymphadenopathy in TB/HIV Co-Infection

2019 ◽  
Vol 19 (4) ◽  
pp. 414-420
Author(s):  
Payam Mehrian ◽  
Abtin Doroudinia ◽  
Moghadaseh Shams ◽  
Niloufar Alizadeh
Keyword(s):  
Lymph Nodes ◽  
Cross Sectional Study ◽  
Short Axis ◽  
Mediastinal Lymph Nodes ◽  
Sectional Study ◽  
Cross Sectional ◽  
Immunodeficiency Virus ◽  
Hilar Adenopathy ◽  
The Right ◽  
Pulmonary Abnormalities

Background: Intrathoracic Lymphadenopathy (ITLN) in Human Immunodeficiency Virus (HIV) infected patients may have various etiologies and prognoses. Etiologies of ITLN can be distinguished based on the distribution of enlarged lymph nodes. Sometimes tuberculosis (TB) is the first sign of underlying HIV infection. Objective: We sought to determine ITLN distribution and associated pulmonary findings in TB/HIV co-infection using Computed Tomography (CT) scan. Methods: In this retrospective, observational, cross-sectional study, chest CT scans of 52 patients with TB/HIV co-infection were assessed for enlarged intrathoracic lymph nodes (>10 mm in short axis diameter), lymphadenopathy (LAP) distribution, calcification, conglomeration, the presence of hypodense center and associated pulmonary abnormalities. LAP distribution was compared in TB/HIV co-infection with isolated TB infection. Results: Mediastinal and/or hilar LAP were seen in 53.8% of TB/HIV co-infection patients. In all cases, LAP was multinational. The most frequent stations were right lower paratracheal and subcarinal stations. Lymph node conglomeration, hypodense center and calcification were noted in 25%, 21.4% and 3.5% of patients, respectively. LAP distribution was the same as that in patients with isolated TB infection except for the right hilar, right upper paratracheal and prevascular stations. All patients with mediastinal and/or hilar adenopathy had associated pulmonary abnormalities. Conclusion: All patients with TB/HIV co-infection and mediastinal and/or hilar adenopathy had associated pulmonary abnormalities. Superior mediastinal lymph nodes were less commonly affected in TB/HIV co-infection than isolated TB.

Aortic root measurement on CT: linear dimensions, aortic root area and comparison with echocardiography. A retrospective cross sectional study

2021 ◽  
Vol 94 (1121) ◽  
pp. 20201232
Author(s):  
Kai'En Leong ◽  
Henry Knipe ◽  
Simon Binny ◽  
Heather Pascoe ◽  
Nathan Better ◽  
...  
Keyword(s):  
Aortic Root ◽  
Intraclass Correlation ◽  
Maximal Dimension ◽  
Short Axis ◽  
Cross Sectional ◽  
Root Area ◽  
Linear Dimensions ◽  
Root Measurement ◽  
Better Than ◽  
Excellent Reproducibility

Objective: We sought to assess the different CT aortic root measurements and determine their relationship to transthoracic echocardiography (TTE). Methods: TTE and ECG-gated CT images were reviewed from 70 consecutive patients (mean age 54 ± 18 years; 67% male) with tricuspid aortic roots (trileaflet aortic valves) between Nov 2009 and Dec 2013. Three CT planes (coronal, short axis en face and three-chamber) were used for measurement of nine linear dimensions. TTE aortic root dimension was measured as per guidelines from the parasternal long axis view. Results: All CT short axis measurements of the aortic root had excellent reproducibility (intraclass correlation coefficient, ICC 0.96–0.99), while coronal and three-chamber planes had lower reproducibility with ICC 0.90 (95% CI 0.84–0.94) and ICC 0.92 (0.87–0.95) respectively. CT coronal and short axis maximal dimensions were systematically larger than TTE (mean 2 mm larger, p < 0.001), while CT cusp to commissure measurements were systematically smaller (CT RCC-comm mean 2 mm smaller than TTE, p < 0.001). All CT short axis measurements had excellent correlation with aortic root area with CT short axis maximal dimension marginally better than the rest (Pearson’s R 0.97). Conclusion: Systematic differences exist between CT and TTE dependent on the CT plane of measurement. All CT short axis measurements of the aortic root had excellent reproducibility and correlation with aortic root area with maximal dimension appearing marginally better than the rest. Our findings highlight the importance of specifying the chosen plane of aortic root measurement on CT. Advances in knowledge: Systematic differences in aortic root dimension exist between TTE and the various CT measurement planes. CT coronal and short axis maximal dimensions were systematically larger than TTE, while CT cusp to commissure measurements were smaller. CT readers should indicate the plane of measurement and the specific linear dimension to avoid ambiguity in follow-up and comparison.

scholarly journals Corrosion Resistance of Fiber-reinforced Geopolymer Structural Concrete in a Simulated Marine Environment

2021 ◽  
Author(s):  
Khaled Sobhan ◽  
Francisco Martinez ◽  
D.V. Reddy
Keyword(s):  
Corrosion Resistance ◽  
Marine Environment ◽  
Electrochemical Method ◽  
Ordinary Portland Cement ◽  
Load Capacity ◽  
Fiber Reinforced ◽  
Structural Concrete ◽  
Accelerated Corrosion ◽  
Damaged Beams

The corrosion resistance of fly ash-based geopolymer structural concrete (GPC), with or without fibers, was investigated in a simulated marine environment, and compared with that of ordinary Portland cement structural concrete. The corrosion behavior is studied through an electrochemical method for inducing accelerated corrosion. The fiber-reinforced specimens contained polyolefin fibers in the amounts of 0.1%, 0.3%, and 0.5% by volume. Several artificial corrosion conduits were introduced into the specimens reaching up to the rebars. This process enhanced the rate of laboratory corrosion in GPC. The corrosion-damaged beams were then analyzed through a method of crack scoring, and determination of steel mass loss and residual flexural load capacity. The fiber-reinforced corroded GPC beams showed a 24% reduction in crack scores, and a 109% increase in residual flexural load capacity, compared to unreinforced corroded GPC beams. This shows promise of fiber-reinforced GPC as a sustainable structural material in the marine environment.

scholarly journals Load bearing capacity of thin-walled rectangular and I-shaped steel sections of short both empty and concrete-filled columns

2021 ◽  
Vol 15 (58) ◽  
pp. 77-85
Author(s):  
Amor Bouaricha ◽  
Naoual Handel ◽  
Aziza Boutouta ◽  
Sarah Djouimaa
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Load Capacity ◽  
Cross Sectional ◽  
Short Columns ◽  
Cross Section Area ◽  
Section Area ◽  
Specimen Height ◽  
Steel Sections ◽  
Thin Walled

In this experimental work, strength results obtained on short columns subjected to concentric loads are presented. The specimens used in the tests have made of cold-rolled, thin-walled steel. Twenty short columns of the same cross-section area and wall thickness have been tested as follows: 8 empty and 12 filled with ordinary concrete. In the aim to determine the column section geometry with the highest resistance, three different types of cross-sections have been compared: rectangular, I-shaped unreinforced and, reinforced with 100 mm spaced transversal links. The parameters studied are the specimen height and the cross-sectional steel geometry. The registered experimental results have been compared to the ultimate loads intended by Eurocode 3 for empty columns and by Eurocode 4 for compound columns. These results showed that a concrete-filled composite column had improved strength compared to the empty case. Among the three cross-section types, it has been found that I-section reinforced is the most resistant than the other two sections. Moreover, the load capacity and mode of failure have been influenced by the height of the column. Also, it had noted that the experimental strengths of the tested columns don’t agree well with the EC3 and EC4 results.

scholarly journals Reduction of the bearing capacity of a thin-walled steel beam-column as a result of uniform corrosion

2018 ◽  
Vol 196 ◽  
pp. 01046
Author(s):  
Aniela Glinicka ◽  
Michał Maciąg
Keyword(s):  
Bearing Capacity ◽  
Load Capacity ◽  
Critical Force ◽  
Uniform Corrosion ◽  
Load Bearing Capacity ◽  
Cross Sectional ◽  
Surface Corrosion ◽  
Steel Bars ◽  
Interactive Relationship ◽  
Thin Walled

The paper presents the analysis of the load-bearing capacity of thin-walled steel bars such as beam-column. It was assumed that the rods are subject to uniformly distributed surface corrosion in the atmosphere over their entire length. As a result of corrosion, the mass loss of these rods, i.e. the thickness of the cross-sectional walls of the rod are evenly reduced. Therefore, the dependence of the critical force - the eccentricity changes. The theory of stability of thin-walled bars was used to calculate the load capacity of the rod. To calculate changes in the load capacity of the rod, an interactive relationship was used that combines compression with bending. A calculation example of the load capacity of an eccentrically compressed rod with a “C” section which has been corroded has been presented.

scholarly journals Experimental Study on Corrosion and Mechanical Behavior of Main Cable Wires Considering the Effect of Strain

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 753 ◽  
Author(s):  
Fangyuan Xu ◽  
Yuanli Chen ◽  
Xianglong Zheng ◽  
Rujin Ma ◽  
Hao Tian
Keyword(s):  
Elastic Modulus ◽  
Mass Loss ◽  
Stress Level ◽  
Corrosion Test ◽  
Ultimate Load ◽  
Cross Sectional ◽  
Accelerated Corrosion ◽  
Yield Load ◽  
Accelerated Corrosion Test ◽  
Corrosion Time

To study the corrosion degradation of cable wires in a bridge’s life, this research work created an accelerated corrosion test device, which sought to identify an optimal constant strain level. An accelerated corrosion test was carried out and the corroded specimens were scanned using super depth 3D microscopy technology. Mass loss and minimum cross-sectional diameter was measured to understand the degradation characteristics of cable wires at variable strains and corrosion time. The variation of elastic modulus, yield load, and ultimate load of corroded wires, subjected to a tensile test, were analyzed. The experimental results illustrate that the average mass loss ratio of the corroded cable wires increases nonlinearly as corrosion time increases. The higher the stress level, the more serious the corrosion level. The minimum cross-sectional diameter has good correlation with corrosion time and stress level. The elastic modulus of wires does not change significantly with the increase of corrosion time. Yield load and ultimate load decreases with the increase of strain level, and the rates of decline under different strains are nonlinear.

PVCO Pipeline Performance Under Large Ground Deformation

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Brad P. Wham ◽  
Christina Argyrou ◽  
Thomas D. O'Rourke ◽  
Harry E. Stewart ◽  
Timothy K. Bond
Keyword(s):  
Polyvinyl Chloride ◽  
Large Scale ◽  
Ground Deformation ◽  
Load Capacity ◽  
Compressive Load ◽  
Soil Liquefaction ◽  
Compression Tests ◽  
Cross Sectional ◽  
Joint Rotation ◽  
Statistical Characterization

Technological advances have improved pipeline capacity to accommodate large ground deformation associated with earthquakes, floods, landslides, tunneling, deep excavations, mining, and subsidence. The fabrication of polyvinyl chloride (PVC) piping, for example, can be modified by expanding PVC pipe stock to approximately twice its original diameter, thus causing PVC molecular chains to realign in the circumferential direction. This process yields biaxially oriented polyvinyl chloride (PVCO) pipe with increased circumferential strength, reduced pipe wall thickness, and enhanced cross-sectional flexibility. This paper reports on experiments performed at the Cornell University Large-Scale Lifelines Testing Facility characterizing PVCO pipeline performance in response to large ground deformation. The evaluation was performed on 150-mm (6-in.)-diameter PVCO pipelines with bell-and-spigot joints. The testing procedure included determination of fundamental PVCO material properties, axial joint tension and compression tests, four-point bending tests, and a full-scale fault rupture simulation. The test results show that the performance of segmental PVCO pipelines under large ground deformation is strongly influenced by the axial pullout and compressive load capacity of the joints, as well as their ability to accommodate deflection and joint rotation. The PVCO pipeline performance is quantified in terms of its capacity to accommodate horizontal ground strain, and compared with a statistical characterization of lateral ground strains caused by soil liquefaction during the Canterbury earthquake sequence in New Zealand.

scholarly journals The Behavior of a Strengthened Steel Beam Section Under Eccentric Loadings

2021 ◽  
Vol 318 ◽  
pp. 03007
Author(s):  
Mohammed M. Rasheed ◽  
Kamal Sh. Mahmoud ◽  
Saad Khalaf Mohaisen ◽  
Mohammed Z. Yousif
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
The Other ◽  
Steel Beams ◽  
Steel Beam ◽  
Ultimate Load Capacity ◽  
Cross Sectional ◽  
External Prestressing ◽  
Beam Section ◽  
Prestressing Strand

Thirteen simply supported steel samples have been tested to explain the effects of strengthening steel beams using an external prestressing strand. The samples have the same cross-sectional dimensions and overall length. One steel beam without strengthening was taken as a reference, while the other twelve of them had been strengthening by two external strands at various eccentricity locations and jacking stresses. The strengthening by external prestressing strands is sub-divided into two series according to jacking stress. Each series consists of six steel samples divided according to the eccentricity location of prestressing strand. During tests, it was found that the Load deflection response for the strengthened samples is stiffer as compared with the reference. The increasing percentage in ultimate load capacity was increased to 0.347, 2.758, 3.921, 8.898, 9.326, and 10.256% for beams under jacking stress of 1120 MPa, while increasing percentage in ultimate load capacity were increased to 0.17, 26, 33, 48.5, 13.7, and 69.56% for beams under jacking stress of 815 MPa. On the other hand, the maximum percentages of deflection were decreased to 4.88, 2.44, 20.62, 15, and 9.7% when the jacking stress increase from 815 to 1120 MPa and the ratio of the quarter to mid-span deflection (δ quarter / δ mid) is about 0.528 and 0.497 when jacking stress is 1120 and 815 MPa respectively. So, the increase in jacking stresses from 815 to 1120 MPa will not be preferable because it has a little increasing percentage in stiffening and behaviors compared with other tested beams at the same condition.

scholarly journals FAKTOR-FAKTOR YANG BERHUBUNGAN DENGAN PERILAKU SAFETY DRIVING PADA SUPIR TRAVEL DI PT. LIBRA WISATA TRANSPORT

2020 ◽  
Vol 4 (1) ◽  
pp. 1-10
Author(s):  
Ade Dita Puteri ◽  
Azimah Mardiatun Nisa
Keyword(s):  
Data Analysis ◽  
Load Capacity ◽  
Sampling Technique ◽  
Chi Square ◽  
Cross Sectional ◽  
Independent Variables ◽  
Dependent Variables ◽  
Chi Square Test ◽  
Employment Education ◽  
Work Knowledge

Safety Driving is the basis for further driving training that pays attention to the safety of drivers and passengers. Safety Driving is influenced by human factors such as age, education, length of work, knowledge, vehicle factors such as passenger load capacity, environmental factors in this condition of road and weather. The purpose of this study is to know the factors relating to correlation safety driving of travel driver at PT. Libra Wisata Transport Pekanbaru year 2019. This research is a quantitative study of analytics with a cross-sectional approach. This research was conducted on June 20-25, 2019 with the population in this research is the travel driver of PT. Libra Wisata Transport Pekanbaru, which was 40 people using the Total Sampling technique. independent variables are age, employment, education, length of work, knowledge, and driving completeness, while the dependent variables are the behavior of Safety Driving. The instruments used in data collection are questionnaires. Data analysis is conducted with the analysis of univariate and bivariate with Chi-Square test. The results of the research can be a relationship between age, employment, education, duration of work, knowledge and completeness of driving with the behavior of Safety Driving. It is suggested to the travel to be able to conduct training on Safety Driving to the all of driver, and conduct evaluation on the implementation of Safety Driving training, so that the results of the training can make the driver Act securely In driving. In addition, the driver is expected to always obey the ordinances of the traffic provisions.

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