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.

scholarly journals Strength Deterioration of Concrete in Sulfate Environment: An Experimental Study and Theoretical Modeling

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yingwu Zhou ◽  
Hao Tian ◽  
Lili Sui ◽  
Feng Xing ◽  
Ningxu Han
Keyword(s):  
Residual Life ◽  
Concrete Strength ◽  
Sulfate Solution ◽  
Strength Degradation ◽  
Life Assessment ◽  
Accelerated Corrosion ◽  
Corrosion Depth ◽  
Strength Deterioration ◽  
Accelerated Corrosion Test ◽  
Residual Life Assessment

Sulfate corrosion is one of the most important factors responsible for the performance degradation of concrete materials. In this paper, an accelerated corrosion by a sulfate solution in a dry-wet cycle was introduced to simulate the external sulfate corrosion environment. The deterioration trend of concrete strength and development law of sulfate-induced concrete corrosion depth under sulfate attacks were experimentally studied. The damaged concrete section is simply but reasonably divided into uncorroded and corroded layers and the two layers can be demarcated by the sulfate corrosion depth of concrete. The accelerated corrosion test results indicated that the strength degradation of concrete by sulfate attack had a significant relation with the corrosion depth. Consequently, this paper aims to reveal such relation and thus model the strength degradation law. A large amount of experimental data has finally verified the validity and applicability of the models, and a theoretical basis is thus provided for the strength degradation prediction and the residual life assessment of in-service concrete structures under sulfate attacks.

scholarly journals Formation Tracking Control and Obstacle Avoidance of Unicycle-Type Robots Guaranteeing Continuous Velocities

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4374
Author(s):  
Jose Bernardo Martinez ◽  
Hector M. Becerra ◽  
David Gomez-Gutierrez
Keyword(s):  
Obstacle Avoidance ◽  
Tracking Control ◽  
Global Coordinate System ◽  
Avoidance Task ◽  
Time Varying ◽  
Control Laws ◽  
Formation Tracking ◽  
Control Scheme ◽  
First Time ◽  
Hierarchical Scheme

In this paper, we addressed the problem of controlling the position of a group of unicycle-type robots to follow in formation a time-varying reference avoiding obstacles when needed. We propose a kinematic control scheme that, unlike existing methods, is able to simultaneously solve the both tasks involved in the problem, effectively combining control laws devoted to achieve formation tracking and obstacle avoidance. The main contributions of the paper are twofold: first, the advantages of the proposed approach are not all integrated in existing schemes, ours is fully distributed since the formulation is based on consensus including the leader as part of the formation, scalable for a large number of robots, generic to define a desired formation, and it does not require a global coordinate system or a map of the environment. Second, to the authors’ knowledge, it is the first time that a distributed formation tracking control is combined with obstacle avoidance to solve both tasks simultaneously using a hierarchical scheme, thus guaranteeing continuous robots velocities in spite of activation/deactivation of the obstacle avoidance task, and stability is proven even in the transition of tasks. The effectiveness of the approach is shown through simulations and experiments with real robots.

Application of an Improved Colored Petri Net Modeling Method in Certain Missile Training System

2015 ◽  
Vol 742 ◽  
pp. 330-334
Author(s):  
Chun Jian Wang ◽  
Wei Yue ◽  
Hai Yan Ji
Keyword(s):  
Complex System ◽  
Petri Net ◽  
Time Use ◽  
Training System ◽  
New Method ◽  
Mathematics Model ◽  
Research Approach ◽  
Complex Environments ◽  
Training Simulator ◽  
First Time

In allusion to the need of analyzing complex system, we have proposed a method named multi-grade color Petri net. We for the first time use this new method to analyze a missile training simulator system. This model can accurately reflect the complex environments of the system and avoid the difficulty occurring often in developing accurate mathematics model by using classical research approach.

scholarly journals Vehicle accelerated corrosion test procedures for automotive in Malaysia

2016 ◽  
Vol 90 ◽  
pp. 01040 ◽  
Author(s):  
Liza Anuar ◽  
Astuty Amrin ◽  
Roslina Mohammad ◽  
Ali Ourdjini
Keyword(s):  
Corrosion Test ◽  
Test Procedures ◽  
Accelerated Corrosion ◽  
Accelerated Corrosion Test

Study on Corrosion Damage Rule for Two Type of Aluminum Alloy

2014 ◽  
Vol 599-601 ◽  
pp. 111-113
Author(s):  
Dan Feng Zhang ◽  
Xiao Ming Tan ◽  
Dan Gui Zhang ◽  
Fang Zhang ◽  
Wei Zhang
Keyword(s):  
Aluminum Alloy ◽  
Statistical Analysis ◽  
Marine Environment ◽  
Corrosion Test ◽  
Corrosion Damage ◽  
Aircraft Structure ◽  
Accelerated Corrosion ◽  
Damage Repair ◽  
Accelerated Corrosion Test ◽  
Damage Rule

Corrosion exists everywhere. It’s very widespread that the aluminum alloy aircraft structure suffers the corrosion damage under the marine environment particularly. The equivalent accelerated corrosion test of the new aluminum alloy 2B06 and 7B04 was carried out.Corrosion damage was inspected and measured through microscope. The rule of the corrosion damage can be obtained by statistical analysis. And which can supply the reference basis for the corrosion damage repair and evaluating the calendar life.

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

scholarly journals Corrosion Prevention on Coated Rebars and Fiber in R.C Slabs

2018 ◽  
Vol 7 (3.34) ◽  
pp. 36
Author(s):  
Dr M.Tamil Selvi ◽  
Ms. J Hathari Evangalin ◽  
M.s S. Gayathri
Keyword(s):  
Research Work ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Accelerated Corrosion ◽  
Structural Problems ◽  
Nylon Fiber ◽  
Cell Measurement ◽  
Accelerated Corrosion Test ◽  
Rc Slabs ◽  
Corrosion Of Steel

Concrete structures prevail primarily due to prior attrition of steel due to preterm failure of rebars. The major cause of deterioration is the corrosion of the steel reinforcement, that can lead to structural problems. By utilizing our knowledge on corrosion of steel reinforcement, concrete structures could be made more durable. The research work is intend at arrestcorrosion in RC slabs by glazing silicon tombac to the steel rods. Nylon fiber is induced in concrete to attain strength for the concrete. A study report carried the effects of coating material between the conventional and fibers in concrete was compared with that of uncoated material between the conventional and fiber in concrete rebar’s. A continuous corrosion process is accelerated by inducing direct current to rebars. Process used to prompt corrosion is Accelerated corrosion test and Half-cell measurement.  

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