Study on Similarity Criterion of Chloride Diffusion Coefficient under Continual Immersion of Marine Prestressed Concrete Structures

2017 ◽  
Vol 45 (6) ◽  
pp. 258-261
Author(s):  
XU Xianzheng ◽  
Keyword(s):  
Diffusion Coefficient ◽  
Prestressed Concrete ◽  
Concrete Structures ◽  
Similarity Criterion ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient

Influence of the Pretreatment on the Concrete Chloride Diffusion Coefficient

2011 ◽  
Vol 477 ◽  
pp. 382-387
Author(s):  
Jia Cheng Li ◽  
Wen Ying Guo ◽  
Jing Wei Wu ◽  
Yi Bo Yang
Keyword(s):  
Diffusion Coefficient ◽  
Concrete Structures ◽  
Chloride Diffusion ◽  
Experimental Result ◽  
Chloride Diffusion Coefficient ◽  
Ultrasonic Bath ◽  
Vacuum Saturation ◽  
Chloride Migration ◽  
Relationship Of ◽  
The Relationship

The pretreatment of concrete rapid chloride migration coefficient (RCM) method in different standard is different in China. However the influence of pretreatment on the experimental result is uncertain, which leads to poor comparability about the results between different standards and trouble in evaluating the durability of concrete structures. The influence of the pretreatment on the chloride diffusion coefficient was studied by contrastive method. On the base of the results a suitable pretreatment of RCM method was proposed. The results are as followings: (1) the influence of pretreatment on the chloride migration coefficient of concrete with 0.45 W/B is insignificant. The influence of pretreatment on the chloride migration coefficient of concrete with other W/B is significant, and the influence increase with the lower w/b.; (2) the chloride diffusion coefficient will increase after the ultrasonic bath and vacuum saturation, and the influence of the ultrasonic bath is larger. Considering the judgment to the durability of structure, the ultrasonic bath and the vacuum saturation are suggested to be used; (3) on the condition of the same anode and cathode solution, the chloride diffusion coefficient in accordance with JTG / T B07-01-2006 standard is usually higher than that in accordance with GB/T50082-2009 standard; (4) the relationship of the chloride diffusion coefficient between mortar and concrete specimens is uncertain under different proportion and curing system, so the mortar specimens can not replace the concrete specimens for the RCM method.

Microstructure Analysis on LILW Waste Disposal Facility by Accelerated Steel Corrosion Tests

2013 ◽  
Vol 378 ◽  
pp. 194-197
Author(s):  
Ki Beom Kim ◽  
Jang Hwa Lee ◽  
Do Gyeum Kim
Keyword(s):  
Diffusion Coefficient ◽  
Waste Disposal ◽  
Concrete Structures ◽  
Steel Corrosion ◽  
Microstructure Analysis ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Reinforcing Bar ◽  
Disposal Facility ◽  
Chloride Attack

Concrete structures such as LILW waste disposal facility located near the sea may suffer from chloride attack damages. This study aims to analysis mock-up test for acceleration corrosion of reinforcing bar and its deterioration in concrete structures by XRD and chloride diffusion coefficient. Corrosion acceleration experiment test has been developed and used to evaluate the effect of corrosion of reinforcing bar caused by seawater on engineered barrier of LILW waste disposal facility.

scholarly journals Application of inverse methodology to estimation of chloride diffusion coefficient in concrete of prestressed precast slab

2018 ◽  
Vol 174 ◽  
pp. 01008
Author(s):  
Zofia Szweda ◽  
Zbigniew Buliński
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Equation ◽  
Prestressed Concrete ◽  
Precast Concrete ◽  
Chloride Penetration ◽  
Chloride Diffusion ◽  
Concrete Slabs ◽  
Chloride Diffusion Coefficient ◽  
Linear Diffusion ◽  
Estimated Parameters

Work presents an investigation of chloride penetration of HC-500 prestressed concrete slabs made of precast concrete. This type of concrete slabs is widely used to construct floors in steel or reinforced concrete framing buildings. In such solutions ceiling can be considered as a simple-supported beam. Considered precast concrete was made of C50/C60 concrete with use of Portland cement CEM II 52.5 R. Investigated specimens were sampled directly from the upper part of prestressed concrete slabs. The process of chloride penetration in concrete can be described by the non-linear diffusion equation. In the paper Bayesian inverse technique was applied to estimate diffusion coefficient of chloride in concrete treated as a saturated porous material. Unknown distribution of estimated parameters was sampled with use of Metropolis-Hastings algorithm which allowed us to obtain unknown values and their error bounds. Obtained values of diffusion coefficient were confronted against values obtained with use of norms: NT BUILD 443 and ASTM C 1556 - 03 and against previously developed methodology based on the analytical solution of the diffusion equation.

A Probabilistic-Based Durability Analysis of Concrete Structures Exposed to Chloride Containing Environment

2012 ◽  
Vol 204-208 ◽  
pp. 3282-3286
Author(s):  
Wei Hua Shi ◽  
Zhi Wu Yu ◽  
Ya Chuan Kuang
Keyword(s):  
Diffusion Coefficient ◽  
Life Prediction ◽  
Chloride Transport ◽  
Concrete Structures ◽  
Chloride Diffusion ◽  
Chloride Ingress ◽  
Chloride Diffusion Coefficient ◽  
Time Dependency ◽  
Durability Analysis

Time dependency of chloride transport has been studied and an improving model for predicting the apparent chloride diffusion coefficient has been proposed. A probabilistic-based durability analysis to estimate failure probability on the chloride ingress into concrete has been carried out. Results of the analysis demonstrate that the improving model in this paper is appropriate for long term service life prediction of concrete structures exposed to chloride containing environment.

scholarly journals Experimental Study on Effective Chloride Diffusion Coefficient of Cement Mortar by Different Electrical Accelerated Measurements

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 240
Author(s):  
Jianlan Chen ◽  
Jiandong Wang ◽  
Rui He ◽  
Huaizhu Shu ◽  
Chuanqing Fu
Keyword(s):  
Diffusion Coefficient ◽  
Cement Mortar ◽  
Early Stage ◽  
Chloride Concentration ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Good Consistency ◽  
Determination Methods

This study investigated the effective chloride diffusion coefficient of cement mortar with different water-to-cement ratio (w/c) under electrical accelerated migration measurement. The cumulative chloride concentration in anode cell solution and the cumulative chloride concentration drop in the cathode cell solution was measured by RCT measurement and the results were further used to calculate the chloride diffusion coefficient by Nordtest Build 355 method and Truc method. The influence of w/c on cement mortar’s chloride coefficient was investigated and the chloride diffusion coefficient under different determination methods were compared with other researchers’ work, a good consistency between this work’s results and literatures’ results was obtained. The results indicated that the increased w/c of cement mortar samples will have a higher chloride diffusion coefficient. The cumulative chloride concentration drop in the cathode cell solution will have deviation in early stage measurement (before 60 h) which will result in overestimation of the effective chloride diffusion coefficient.

scholarly journals Effects after 1500 Hardening Days on the Microstructure and Durability-Related Parameters of Mortars Produced by the Incorporation of Waste Glass Powder as a Clinker Replacement

2021 ◽  
Vol 13 (7) ◽  
pp. 3979
Author(s):  
Rosa María Tremiño ◽  
Teresa Real-Herraiz ◽  
Viviana Letelier ◽  
Fernando G. Branco ◽  
José Marcos Ortega
Keyword(s):  
Diffusion Coefficient ◽  
Water Absorption ◽  
Glass Powder ◽  
Cementitious Materials ◽  
Cement Industry ◽  
Waste Glass ◽  
Supplementary Cementitious Materials ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Waste Glass Powder

One of the ways of lessening the CO2 emissions of cement industry consists of replacing clinkers with supplementary cementitious materials. The required service life of real construction elements is long, so it is useful to characterize the performance of these materials in the very long term. Here, the influence of incorporating waste glass powder as a supplementary cementitious material, regarding the microstructure and durability of mortars after 1500 hardening days (approximately 4 years), compared with reference mortars without additions, was studied. The percentages of clinker replacement by glass powder were 10% and 20%. The microstructure was studied using impedance spectroscopy and mercury intrusion porosimetry. Differential thermal and X-ray diffraction analyses were performed for assessing the pozzolanic activity of glass powder at the end of the time period studied. Water absorption after immersion, the steady-state diffusion coefficient, and length change were also determined. In view of the results obtained, the microstructure of mortars that incorporated waste glass powder was more refined compared with the reference specimens. The global solid fraction and pores volume were very similar for all of the studied series. The addition of waste glass powder reduced the chloride diffusion coefficient of the mortars, without worsening their behaviour regarding water absorption after immersion.

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