Chloride Diffusion Coefficient at Reference Time for High Performance Concrete for Bridge Pylons in Marine Environment

2012 ◽  
Vol 24 (4) ◽  
pp. 435-444 ◽  
Author(s):  
Chul-Soo Yoon ◽  
Ki-Hyun Kim ◽  
Woo-Yong Yang ◽  
Soo-Won Cha
Keyword(s):  
Diffusion Coefficient ◽  
Marine Environment ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Reference Time

scholarly journals Investigation on Durability Performance in Early Aged High-Performance Concrete Containing GGBFS and FA

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Seung-Yup Jang ◽  
Subbiah Karthick ◽  
Seung-Jun Kwon
Keyword(s):  
Diffusion Coefficient ◽  
High Performance ◽  
High Performance Concrete ◽  
Steel Corrosion ◽  
Chloride Ions ◽  
Chloride Diffusion ◽  
Structural Safety ◽  
Concrete Durability ◽  
Chloride Diffusion Coefficient ◽  
Rc Structures

The significance of concrete durability increases since RC (Reinforced Concrete) structures undergo degradation due to aggressive environmental conditions, which affects structural safety and serviceability. Steel corrosion is the major cause for the unexpected failure of RC structures. The main cause for the corrosion initiation is the ingress of chloride ions prevailing in the environment. Hence quantitative evaluation of chloride diffusion becomes very important to obtain a chloride diffusion coefficient and resistance to chloride ion intrusion. In the present investigation, 15 mix proportions with 3 water-to-binder ratios (0.37, 0.42, and 0.47) and 3 replacement ratios (0, 30, and 50%) were prepared for HPC (high-performance concrete) with fly-ash and ground granulated blast furnace slag. Chloride diffusion coefficient was measured under nonstationary condition. In order to evaluate the microstructure characteristics, porosity through MIP was also measured. The results of compressive strength, chloride diffusion, and porosity are compared with electrical charges. This paper deals with the results of the concrete samples exposed for only 2 months, but it is a part of the total test plan for 100 years. From the work, time-dependent diffusion coefficients in HPC and the key parameters for durability design are proposed.

Inner Damage and Anti-Chloride Penetration of High-Performance Concrete under Axial Tensile Load

2011 ◽  
Vol 261-263 ◽  
pp. 1210-1214
Author(s):  
Fu Xiang Jiang ◽  
Lei Xin ◽  
Tie Jun Zhao ◽  
Xiao Mei Wan
Keyword(s):  
Diffusion Coefficient ◽  
High Performance ◽  
High Performance Concrete ◽  
Tensile Load ◽  
Total Porosity ◽  
Tensile Loading ◽  
Chloride Penetration ◽  
Chloride Diffusion ◽  
Uniaxial Tensile ◽  
Chloride Diffusion Coefficient

The total porosity of high performance concrete specimens after different level uniaxial tensile loading were measured to reflect the damage degree of mechanical load to the microstructure of the concrete. Meanwhile, considering the environmental characteristics of the ocean tidal zone, chloride penetration tests of the concrete were carried out with salt solution capillary absorption method. Based on the profile of chloride measured from specimens, chloride diffusion coefficients of the concrete under uniaxial tensile load with different levels are determined further by Fick’s second law. Results show that both of total porosity and chloride diffusion coefficient of the concrete are increased significantly after short-term tensile loading. And the evolutions of the porosity and chloride diffusion coefficient are similar with the development of micro-cracks under uniaxial tensile load.

On the Time Dependency of the Chloride Diffusion in High Performance Concrete

2013 ◽  
Vol 721 ◽  
pp. 148-152
Author(s):  
Zheng Chen ◽  
Xi Bin Zhao ◽  
Yan Hua Yuan ◽  
Zhong Hua Wang ◽  
Lu Feng Yang ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Time Dependency ◽  
Long Period ◽  
Age Factor ◽  
Astm C1202

The chloride diffusion coefficient of concrete is time dependent. The high performance concrete (HPC) was prepared and the specimens were tested by ASTM C1202 and the durability of HPC in long period is analyzed with the time dependency of diffusion in this paper. The results show that the chloride diffusion coefficients of the HPC with only fly ash are large than those of the HPC with multi-admixtures, but the attenuation of the chloride diffusion coefficients of the formers are faster than the latters. The analysis results show that the chloride concentrations in concrete is over estimated when time-dependence of chloride diffusion is not considered, and the durability of concrete in long period is determined by both chloride diffusion coefficient and age factor.

Boundary Element Analysis of Accelerated Chloride Diffusion in High Performance Concrete

2013 ◽  
Vol 842 ◽  
pp. 151-155
Author(s):  
Yi Wang ◽  
Wo Cheng Hang ◽  
Lu Feng Yang ◽  
Zheng Chen
Keyword(s):  
Diffusion Coefficient ◽  
Boundary Element ◽  
High Performance ◽  
Numerical Solutions ◽  
High Performance Concrete ◽  
Chloride Concentration ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Chloride Diffusion ◽  
Chloride Permeability

This paper aims to analyze accelerated chloride diffusion in high performance concrete (HPC) blended with mineral admixture by using boundary element method (BEM). Rapid chloride permeability test (RCPT) was employed and executed. The experiment proves that the highest resistance to chloride permeability can be acquired in the quaternary-blended concretes (ordinary portland cement + fly ash + blast furnace slag + silica fume). A chloride diffusion BEM model was established according to the diffusion coefficient calculated from the charge passed. The numerical solutions agree with experiments well. It can be inferred that the acceleration degree of RCPT is not the same in different mix proportion. Besides, the results also suggest that the low chloride permeability of the concretes with mineral admixtures may be attributed to the lower diffusion coefficient and the lower surface chloride concentration.

Durability Design of Marine Concrete Structure Considering the Influence of Load

2015 ◽  
Vol 744-746 ◽  
pp. 59-64 ◽  
Author(s):  
Jian Bo Xiong ◽  
Chun Lin Deng
Keyword(s):  
Diffusion Coefficient ◽  
Tensile Stress ◽  
Concrete Structure ◽  
High Performance Concrete ◽  
Chloride Ion ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Ion Diffusion ◽  
Exponential Relationship ◽  
Chloride Ion Diffusion

In this paper, based on accelerated testing indoors, under the action of bending tensile stress on a marine high-performance concrete chloride ion diffusion coefficient, the results show that: Subjected to bend under the action of tensile stress and do not withstand the test piece chloride diffusion coefficient increases with increasing stress levels, different tensile stress and does not bear the stress of the concrete chloride ion diffusion coefficient ratio (Dη/D0) exponential relationship with the stress level (η). In addition, addition, for a domestic Bridge, preliminary design to determine typical parameters of components and their environment is proposed to consider the durability of concrete structure load control index calculation method, to establish a "design life - chloride ion diffusion coefficient controlled targets" the correspondence between, for similar projects designed to provide a reference durability.

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