Research on Durability Design of Concrete Structure under Chloride Environment

2014 ◽  
Vol 926-930 ◽  
pp. 623-626
Author(s):  
Ke Feng Zhang
Keyword(s):  
Concrete Structure ◽  
Design Theory ◽  
Design Method ◽  
Theory Model ◽  
Concrete Cover ◽  
Carbonation Depth ◽  
Durability Design ◽  
Chloride Environment ◽  
Cover Thickness ◽  
Chlorine Ion

For concrete structure durability increasingly highlight of problem, focus description has chlorine ion on concrete structure of erosion mechanism, and invaded model and effects factors, derivation out integrated consider concrete of chlorine ion combines capacity, and chlorine ion proliferation coefficient of time dependence, and concrete structure micro-defects effects and the mixed coagulation s performance of practical proliferation equation, established has for forecast concrete using life of chlorine ion proliferation theory model, made intends built structure in chlorine ion environment Xia durability design thought and design method, Perfected design theory of durability of concrete and carbonation model design based on Carbonation depth of concrete during the period, compared with the concrete cover thickness, for engineering design and revision of the specification reference.

scholarly journals The Investigation of The Different Types of the Ground Rebar Spacers with Proposing New Design Rebar Space Mixed of Concrete Palstic

2020 ◽  
Vol 1 (1) ◽  
pp. 01-06
Author(s):  
Sevar Neamat ◽  
Mahmood Shamsborhan
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Plastic Material ◽  
Vital Role ◽  
Concrete Cover ◽  
Cementitious Material ◽  
Advantages And Disadvantages ◽  
Different Types ◽  
Review Study ◽  
Cover Thickness

The reinforcing spacers are commonly prepared from cementitious material, plastic or metals. These spacers are prepared to provide the reinforcing steel with ensuring that the requested concrete cover thickness is attained to guard surrounded steel from corrosion. Also, they pretend a vital role in the concrete structure performance. The toughness of reinforced concrete buildings remains extremely reliant on the features of the protection of concrete to be strong with thickness. A disappointment in finding cover thickness is considered the main impact on early deterioration within the steel, whichever in chance is a chief weaken method in reinforced concrete constructions. The specified study offerings a review study on the investigation of the advantages and disadvantages of six factors in various types concerning the ground rebar spacers studies. As a result, different types of ground rebar spacers have been compared and the new rebar spacer has been designed mixed of concrete_ plastic material

Chloride Ion Erosion in Concrete under Sustained Axial Pressure

2016 ◽  
Vol 680 ◽  
pp. 402-405
Author(s):  
Zong Ming Yang ◽  
Wei Hong Li ◽  
Yi Han Wang
Keyword(s):  
Axial Compression ◽  
Concrete Structure ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Reinforcement Corrosion ◽  
Compression Load ◽  
Durability Design ◽  
Chloride Ion Penetration ◽  
Chloride Environment ◽  
Ion Erosion

As one of the leading causes of influencing the durability of concrete structure, reinforcement corrosion has been a central issue. Erosion of chloride ions on the concrete structure is influenced by many factors. This is not only concerned with its own structural properties, but also to its environment, to withstand the load and other factors. This article has carried on an experiment which researches on the rules of chloride ion penetration in the sustained axial compression after different corrosive time, when the concrete is corroded under the joint action of axial compression load and chlorine salt circulation. The results prove that, with the increase of Intensity of load and the cycle time of chlorine salt, the number of Chloride ion ingress in concrete continues to increase. The experimental results may provide a reference to the durability design of concrete in chloride environment.

Bond Strength Modelling of Corroding Steel Reinforcement in Concrete

2011 ◽  
Vol 255-260 ◽  
pp. 757-761 ◽  
Author(s):  
Roger Zou ◽  
Ahmad Shayan ◽  
Frank Collins
Keyword(s):  
Bond Strength ◽  
Bearing Capacity ◽  
Analytical Model ◽  
Experimental Test ◽  
Concrete Structure ◽  
Concrete Cover ◽  
Simple Analytical Model ◽  
Load Bearing Capacity ◽  
Steel Bar ◽  
Cover Thickness

Corrosion of reinforcement can significantly affect the bond strength between the steel bar and the surrounding concrete thus greatly reducing the load bearing capacity of the concrete structure. In this paper, a simple analytical model is proposed to evaluate the maximum bond strength of corroded concrete with varying rebar diameters and concrete cover thickness. Predicted results compared well with experimental test data.

The Biomimetic Shark Skin Optimization Design Method for Improving Lubrication Effect of Engineering Surface

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Yan Lu ◽  
Meng Hua ◽  
Zuomin Liu
Keyword(s):  
Coefficient Of Friction ◽  
Optimization Design ◽  
Design Method ◽  
Theory Model ◽  
Tribological Performance ◽  
Design Parameters ◽  
Width Ratio ◽  
Textured Surface ◽  
Shark Skin ◽  
Biomimetic Surface

Nature has long been an important source of inspiration for mankind to develop artificial ways to mimic the remarkable properties of biological systems. In this work, a new method was explored to fabricate a biomimetic engineering surface comprising both the shark-skin, the shark body denticle, and rib morphology. It can help reduce water resistance and the friction contact area as well as accommodate lubricant. The lubrication theory model was established to predict the effect of geometric parameters of a biomimetic surface on tribological performance. The model has been proved to be feasible to predict tribological performance by the experimental results. The model was then used to investigate the effect of the grid textured surface on frictional performance of different geometries. The investigation was aimed at providing a rule for deriving the design parameters of a biomimetic surface with good lubrication characteristics. Results suggest that: (i) the increase in depression width ratio Λ decreases its corresponding coefficient of friction, and (ii) the small coefficient of friction is achievable when Λ is beyond 0.45. Superposition of depth ratio Γ and angle's couple under the condition of Λ < 0.45 affects the value of friction coefficient. It shows the decrease in angle decreases with the increase in dimension depth Γ.

Durability design of composite bridges with given life in seasonal freezing region

2021 ◽  
Author(s):  
Xuefei Shi ◽  
Qi Xu
Keyword(s):  
Service Life ◽  
Life Cycle Cost ◽  
Mechanical Performance ◽  
Design Method ◽  
Protective Layer ◽  
Highway Bridges ◽  
Seasonal Freezing ◽  
Durability Design ◽  
Composite Bridges ◽  
Design Requirements

<p>Steel-concrete composite bridges are currently widely used in highway bridges in China. To reduce durability problems in seasonal freezing region, a design method with given service life is used. The service life is given on the basis of the environment condition and design requirements; then the structural design and safety analysis are carried out, and the durability design and analysis of the structural components are conducted. With the consideration of the mechanical performance, construction convenience and life-cycle cost, the structural scheme for bridges using twin-I girders, cross beams and precast full-width deck is recommended. Weather resistant steel is recommended to be used in nonmarine seasonal freezing regions with stabilization treatment, waterproof and drainage design, local anti-corrosion coating. Finally, a design process considering material, protective layer thickness and construction control is proposed to improve concrete deck durability.</p>

Influence of Geometry Parameters on Durability of Concrete Structures Exposed to Chloride Environment

2012 ◽  
Vol 204-208 ◽  
pp. 3194-3200
Author(s):  
Xin Gang Zhou ◽  
Hui Xia
Keyword(s):  
Concrete Structures ◽  
Chloride Content ◽  
Chloride Diffusion ◽  
Rectangular Section ◽  
Circular Section ◽  
Concrete Members ◽  
Numerical Stimulation ◽  
Numerical Computing ◽  
Chloride Environment ◽  
Cover Thickness

Finite difference method (FDM) is used to numerical stimulation analysis for chloride diffusion in concrete. By numerical computing, comparison of chloride content profile in different concrete members with different sectional shapes is made. Calculation and comparison show the chloride content prolife in rectangular and circular section has obvious difference. If the side length of rectangular section is equal to the diameter of circular section, as well as the material property and environment, the chloride content in rectangular section is higher than that in that in circular section. In the calculation example, the chloride content at the depth of reinforcement of circular section is about 50-60% that of rectangular section. This tendency is more remarkable in less section dimension, as well as less cover thickness. With the increasing of section, the ratio of difference becomes to be less until to a constant value. In durability design and service life prediction of concrete structures, the section shape and dimension influence should be taken to consideration.

Production of High-Performance Composite Concrete Segment and Experimental Investigation of Materials

2010 ◽  
Vol 168-170 ◽  
pp. 1042-1045
Author(s):  
Ying Li Gao ◽  
Bao Guo Ma
Keyword(s):  
Service Life ◽  
Concrete Structure ◽  
High Performance ◽  
Concrete Cover ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Volume Deformation ◽  
Volume Stability ◽  
High Performance Composite ◽  
Structure Layer

Tunnel lining concrete segment is the most critical and important structural member of shield tunneling. This investigation designed and produced high-performance composite concrete segment (HCCS). Some key indexes that affect the properties of segment were tested, such as impermeability, volume stability, mechanical property, etc. The results indicated that the impermeability of HCCS concrete cover was excellent and the chloride diffusion coefficient decreased one order of magnitude compared to that of the ordinary segment concrete cover, while the service-life of HCCS increased more than ten-fold. The volume stability of HCCS concrete cover and concrete structure layer were good and the better compatibility in the volume deformation of the whole structure was shown. Furthermore, the mechanical properties of concrete cover and concrete structure layer met the project requirement perfectly, ensuring the higher durability and longer service-life of HCCS effectively.

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