• Title/Summary/Keyword: chloride ion

Search Result 1,122, Processing Time 0.03 seconds

Experimental Study on the Chloride Invasion Resistance Properties of Concrete Containing Mineral Admixtures (혼화재 혼입 콘크리트의 염화물 침투저항성에 관한 실험적 연구)

  • Yoo, Jae-Kang;Kim, Dong-Seuk;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2003.11a
    • /
    • pp.43-48
    • /
    • 2003
  • This paper investigate that the effect of the concrete containing mineral admixtures(pozzolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete added mineral admixtures for 3~4 replacement ratios under W/B ratios ranged from 0.40 to 0.55. For the electrical migration test, Tang and Nilsson's method was used to estimate the migration coefficient of chloride ion. As a results, the W/B ratios, kinds of admixture and replacement ratios, water curing periods had a great effect on the migration coefficient of chloride ion, and the optimal replacement ratios of admixture had a limitation for each admixtures. Also, the addition of mineral admixtures by mass(replacement of OPC) enhanced the resistance of the mixture to chloride penetration compared with the plain concrete. The amount of acid soluble chloride ions and water soluble chloride ions were varied with the kinds of mineral admixtures. The compressive strength was shown related to the migration coefficient of chloride ion, the compressive strength increased with the decreasing migration coefficient of chloride ion. Below the 50MPa, the variation of migration coefficient of concrete added mineral admixtures was bigger than plain concrete.

  • PDF

Experimental Study on the Chloride Invasion Resistance Properties of Concrete Containing Mineral Admixtures (혼화재 혼입 콘크리트의 염화물 침투저항성에 관한 실험적 연구)

  • 유재강;김동석;이상수
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2003.05a
    • /
    • pp.43-48
    • /
    • 2003
  • This paper investigate that the effect of the concrete containing mineral admixtures(pozzaolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete added mineral admixtures for 3∼4 replacement ratios under W/B ratios ranged from 0.40 to 0.55. For the electrical migration test, Tang and Nilsson's method was used to estimate the migration coefficient of chloride ion. As a results, the W/B ratios, kinds of admixture and replacement ratios, water curing periods had a great effect on the migration coefficient of chloride ion, and the optimal replacement ratios of admixture had a limitation for each admixtures. Also, the addition of mineral admixtures by mass(replacement of OPC) enhanced the resistance of the mixture to chloride penetration compared with the plain concrete. The amount of acid soluble chloride ions and water soluble chloride ions were varied with the kinds of mineral admixtures. The compressive strength was shown related to the migration coefficient of chloride ion, the compressive strength increased with the decreasing migration coefficient of chloride ion. Below the 50MPa, the variation of migration coefficient of concrete added mineral admixtures was bigger than plain concrete.

  • PDF

Chloride Ion Penetration Resistance of Mortars including Expanded Vermiculite Immobilizing Bacteria (박테리아 흡착 팽창질석을 혼입한 모르타르의 염소이온 침투 저항성)

  • Jung, Seung-Bae;Yang, Keun-Hyeok
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2017.11a
    • /
    • pp.151-152
    • /
    • 2017
  • This tests examined the effectiveness of bacteria slime on the chloride ion penetration resistance of cement mortar. Test results exhibited that the chloride ion penetration depth of mortars including 5% expanded vermiculite immobilizing bacteria was 17% smaller than that of the control mortar without expanded vermiculite.

  • PDF

Influence of Mineral Admixtures on the Diffusion Coefficient for Chloride Ion in Concrete (광물질 혼화재가 콘크리트의 염소이온 확산계수에 미치는 영향)

  • Bae, Su-Ho;Park, Jae-Im;Lee, Kwang-Myong;Choi, Sung
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.4A
    • /
    • pp.347-353
    • /
    • 2009
  • The qualitative factors influencing the ingress of chloride ion into concrete are water-binder (W/B) ratio, cement type, age, chloride ion concentration of given environment, wet and dry conditions, etc. Thus, an objective of this experimental research is to investigate the effects of cement types and environmental conditions on the chloride ion diffusion characteristics in concrete through the chloride ion diffusion test. For this purpose, the diffusion coefficients for chloride ion in concrete with three types of cement such as ordinary portland cement (OPC), binary blended cement (BBC), and ternary blended cement (TBC), were measured for the concrete specimens with W/B ratios of 32%, 38%, and 43%, respectively. The diffusion coefficients for chloride ion were also measured for the concrete specimens with W/B ratio of 43%, which were subjected to standard curing and field exposure conditions. It was observed from the test results that the resistance against chloride ion penetration increased with decreasing W/B ratio and those of BBC and TBC concretes were greater than that of OPC concrete. Therefore, it was revealed that the use of these cements containing mineral admixtures is required to extend the service life of RC structures exposed to chloride environment. On the other hand, it was noted that the resistance against chloride ion penetration of field exposure test specimens was slightly lower than that of standard curing test specimens due to the penetration of chloride ion under the irregular ambient temperature, splash of wave, and cycle of wet and dry.

Influence of Water-Cement Ratios and Curing Conditions on the Diffusion Characteristics of Chloride Ion in Concrete (콘크리트의 염소이온 확산특성에 미치는 물-시멘트비 및 양생조건의 영향)

  • Bae, Su-Ho;Lee, Kwang-Myong;Kim, Jee-Sang;Jung, Sang-Hwa
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.4A
    • /
    • pp.753-759
    • /
    • 2006
  • To predict service life of concrete structures exposed to chloride attack, surface chloride concentration, diffusion coefficient of chloride ion, and chloride corrosion threshold value in concrete, are used as important factors. Of these, as the diffusion coefficient of chloride ion for concrete is strongly influenced by concrete quality and environmental conditions of structures and may significantly change the service life of structures, it is considered as the most important factor for service life prediction. The qualitative factors affecting the penetration and diffusion of chloride ion into concrete are water-cement (W/C) ratio, age, curing conditions, chloride ion concentration of given environment, wet and dry conditions, etc. In this paper the influence of W/C ratio and curing conditions on the diffusion characteristics of chloride ion in concrete was investigated through the chloride ion diffusion test. In the test, the voltages passing through the diffusion cell were measured by accelerated test method using potential difference, and then with the consideration of IR drop ratio the diffusion coefficient of chloride ion for concrete with different W/C ratios were estimated by Andrade's model. Furthermore, under different curing conditions formulas for the estimation of the diffusion coefficient of chloride ion have been proposed by the regression analysis considering the effect of W/C ratio and age.

A Study on the Chloride ion Penetration Characteristic of Concrete containing Ground Granulated Blast Furnace Slag (고로슬래그미분말 치환 콘크리트의 염화물 침투특성에 관한 연구)

  • 김현수;지남용
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2001.05a
    • /
    • pp.997-1002
    • /
    • 2001
  • There are two types of chloride in concrete; one is added as concrete materials' chloride when concrete's mixing, and .the other is penetrated from the air and sea water in the sea-shore area. These chlorides penetrate into concrete, and they are accumulated inside the concrete with aging. This study aimed to evaluate the chloride ion penetration resistance of concrete containing GGBFS in the sea-shore area. Therefore, the specimens made with the replacement ratios(0, 0.30, 0.45, 0.60) of GGBFS were put into 3% NaCl solution according to the chloride accelerating test of JCI-SC3, and then investigated the weight changes, compressive strength, chloride ion with the depths of the specimens by aging. The result is that the diffusion coefficient of chloride ion is decreased with the increase of replacement ratios when compared to OPC

  • PDF

Estimation of Probability Valuable for Diffusion Coefficient of Chloride Ion (염소이온 확산계수의 확률변수 평가)

  • Bae Su Ho;Lee Kwang Myong;Kim Jee Sang;Jung Sang Hwa
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2005.11a
    • /
    • pp.515-518
    • /
    • 2005
  • In recent years, many research works have been carried out in order to obtain a more controlled durability and long-term performance of concrete structures exposed to chloride environments. In particular, the development of new procedures for probability-based durability analysis and design has been proved to be very valuable. To carry out the procedures described above, the statistical properties of design valuables such as diffusion coefficient of chloride ion, surface chloride concentration, and chloride threshold value etc. should be known. For this purpose, this paper presents the statistical properties of the diffusion coefficient of chloride ion such as mean value and standard deviation with water-cement(w/c) ratio and curing conditions, respectively. It was observed from the test that the standard deviation for the diffusion coefficient of chloride ion was found to be small with decrease in the w/c ratio irrespective of curing conditions and that of standard curing was found to be smaller than that of field curing.

  • PDF

Resistance against Chloride Ion and Sulfate Attack of Cementless Concrete (무시멘트 콘크리트의 염소이온 침투 및 황산염 침투 저항성)

  • Lee, Hyun-Jin;Bae, Su-Ho;Kwon, Soon-Oh;Lee, Kwang-Myong;Jeon, Jun-Tai
    • Journal of the Korean Society for Advanced Composite Structures
    • /
    • v.6 no.2
    • /
    • pp.63-69
    • /
    • 2015
  • It has been well known that concrete structures exposed to chloride and sulfate attack environments lead to significant deterioration in their durability due to chloride ion and sulfate ion attack. The purpose of this experimental research is to evaluate the resistance against chloride ion and sulfate attack of the cementless concrete replacing the cement with ground granulated blast furnace slag. For this purpose, the cementless concrete specimens were made for water-binder ratios of 40%, 45%, and 50%, respectively and then this specimens were cured in the water of $20{\pm}3^{\circ}C$ and immersed in fresh water, 10% sodium sulfate solution for 28 and 91 days, respectively. To evaluate the resistance to chloride ion and sulfate attack for the cementless concrete specimens, the diffusion coefficient for chloride ion and compressive strength ratio, mass change ratio, and length change ratio were measured according to the NT BUILD 492 and JSTM C 7401, respectively. It was observed from the test results that the resistance against chloride ion and sulfate attack of the cemetntless concrete were comparatively largely increased than those of OPC concrete with decreasing water-binder ratio.

The Diffusion Property of Chloride Ion into Concrete by Electrically Accelerated Method (전기적인 촉진시험에 의한 콘크리트의 염화물이온 확산특성)

  • Bae, Ju-Seong;Park, Gook-Joon
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.14 no.3
    • /
    • pp.138-143
    • /
    • 2010
  • Recently, as many big marine concrete structures increase, it is necessary that chloride ion diffusion coefficient of concrete shall be evaluated but it will take a long time to evaluate chloride ion diffusion coefficient of concrete. Accordingly, many test methods are suggested to evaluate chloride ion diffusion coefficient in a short period time by the promotion in electro chemical ways but the systematic study for this is insufficient. Therefore, this study evaluates chloride ion penetration and diffusion features by three representative electric promotion tests targeting for three different cements whose ingredients are different and analyzes the correlationship between them. As a result, diffusion features of chloride ion varied according to the cement ingredients and three ingredients cement in which blast furnace slag powder and fly ash are mixed in constant ratio, which shows the most excellent cement diffusion properties. For diffusion properties of chloride ion, the correlationship between test methods are good.

Chloride-ion Test of Seaside Concrete Structure (임해 콘크리트 구조물의 염분 침투량 분석)

  • 이장화;장종탁
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1990.10a
    • /
    • pp.123-124
    • /
    • 1990
  • Seaside concrete structure is deteriorated by chloride-ion, sulphate and salt cristalization in concrete pore. Therefore the amount of these chemical substance should be analyzed for evaluating the durability of seaside concrete structure. In this study, the amount of chloride-ion in concrete was surveyed in order to estimate the damage state of concrete structure within am influence of seawater.

  • PDF