Electrical conductivity, diffusion, and permeability of Portland cement-based mortars

McCarter, William John; Starrs, G.; Chrisp, T. M.

doi:10.1016/s0008-8846(00)00281-7

Cited by 167 publications

(55 citation statements)

References 21 publications

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“…Numerous studies based on this technique were reported, and the effectiveness in measuring these properties of concrete has been shown (McCarter and Brousseau 1990;Keddam et al 1997;Gu 1993;Cabeza et al 2002;Sato and Beaudoin 2011;Scuderi et al 1991). McCarter et al (2000) reported that the electrical conductivity and permeability and the diffusion coefficient of mortar showed a good correlation, which shows the relationship between the electrical conductivity and other properties of cement-based materials. In addition, there have been many studies investigating the correlation between the electrical conductivity and other properties of concrete (Andrade 1993;Streicher and Alexander 1995;Sánchez et al 2011;Ortega et al 2012;Shi et al 1999;Díaz et al 2006;Mercado et al 2012;Buenfeld and Newman 1987;Shane et al 2000;Vedalakshmi et al 2008;Neithalath and Jain 2010;Minagawa et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Electrical Conductivity and Chloride Ingress in Hardened Cement Paste

Kurumisawa

Nawa

2016

ACT

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The transport properties of hardened cement paste (HCP) have been investigated in many studies; the AC impedance method (ACI) is a non-destructive technique employed for this purpose and has been used in investigations of the electrical characteristic and mass transport properties of HCP. However, there are relatively fewer studies investigating chloride ingress in HCP and using the ACI. In this study, the relationship between the electrical conductivity measured by the ACI and chloride ingress was investigated. Backscattered electron image analysis and mercury intrusion porosimetry and water porosity were used to measure the pore structure of HCP, and the chloride ingress depth was measured by an electron probe microanalyzer. There was a high correlation between the porosity and conductivity and between the conductivity and diffusion coefficient of the chloride ions in HCP. This implies that the diffusion coefficient of chloride ions could be estimated by the conductivity measurements.

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Section: Introductionmentioning

confidence: 99%

Electrical Conductivity and Chloride Ingress in Hardened Cement Paste

Kurumisawa

Nawa

2016

ACT

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“…A presença de escória no cimento aumenta a densidade do concreto, assim como a resistência da matriz e a sinuosidade capilar, além de reduzir a concentração iônica nos poros [16,17]. Portanto, ao refinar os poros da microestrutura do concreto, é diminuída a condutividade das amostras e, consequentemente, aumenta-se a RES.…”

Section: Resultados E Discussõesunclassified

Efeito da escória de alto forno na resistividade elétrica superficial do concreto

Gans¹,

Medeiros²,

Lima³

2017

Simpósio Paranaense De Patologia Das Construções

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Resumo: Ao pensar em projetar estruturas de concreto a partir do conceito de durabilidade, a resistividade elétrica torna-se um parâmetro interessante para controle de vida útil, principalmente devido à praticidade de execução do ensaio, caracterizado como não destrutivo. A resistividade é definida como a habilidade do material em transportar cargas elétricas no seu interior, ou seja, no caso do concreto, de difundir os íons através da solução aquosa presente em seus poros. Relacionada à permeabilidade, a resistividade é um indicativo da resistência do concreto à penetração de agentes agressivos, a qual, consequentemente, afeta a velocidade de corrosão das armaduras do concreto. O objetivo deste artigo é comparar a resistividade elétrica superficial (RES) de concretos com dois diferentes tipos de cimento: um com adição de escória de alto forno durante a composição (CP III RS) e outro sem esse tipo de adição (CP V). A RES foi medida pelo método dos quatro pontos. Foi utilizado o mesmo traço 1:1,4:2,1 (cimento: areia: brita) e a mesma relação água/cimento de 0,50 para as duas amostras de concreto investigadas. Os resultados foram analisados nas idades de 28, 60, 90, 120, 150 e 180 dias. Para os concretos com ambos os tipos de cimento foi identificado um aumento da RES com o tempo de ensaio. Porém, no cimento com adição de escória, o fator idade do concretoparâmetro que mede o crescimento da resistividade no tempo -elevou-se 45% em relação ao fator idade das amostras de CP V. A RES foi muito superior para o concreto com cimento de escória de alto forno em todas as idades, atingindo valor 9,7 vezes maior que amostra de concreto com cimento CP V aos 180 dias.Palavras-chave: concreto, resistividade elétrica superficial, escória de alto forno. Abstract:The electrical resistivity is an interesting parameter of service life when thinking of durability of concrete structures, mainly due to the practicality of a non-destructive test method. In the case of concrete, it is defined as the material's ability to transport electric charges by diffusing the ions through the aqueous solution present in its pores. The electrical resistivity indicates the resistance of concrete to the penetration of aggressive agents that may cause corrosion of reinforcement. There are many factors that act directly on this parameter as the microstructure of concrete, the chemical composition of cement, the amount of water used in the mix and the proportion between materials. The aim of this study was to evaluate the change in surface electrical resistivity (SER) of concretes produced with two different types of cement: the blast-furnace slag cement (CP III RS) and a cement without this addition (CP V). It was used the same proportion between materials and the same water/cement ratio for the samples. The SER was measured using the Werner Method (four-point method) for 28, 60, 90, 120, 150 and 180 days. The results indicated that the SER increased with time for both types of cement, although the age factor -parameter that measures the development in ...

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“…Se trata de aplicar una corriente eléctrica de frecuencia variable mediante dos electrodos metálicos y medir su diferencia de potencial. La intensidad ha de ser pequeña para minimizar el efecto electroquímico (17)(18)(19)(20). Otro método, aplicado recientemente, no utiliza electrodos y la corriente eléctrica es inducida mediante un campo magnético variable (21 …”

Section: Procedimiento De Medidas Eléctricas Macroscópicas (Impedanciunclassified

“…It involves applying a variable frequency electric current through two metallic electrodes and measuring its potential difference. The intensity should be small to minimize the electrochemical effect (17)(18)(19)(20). Another method, recently implemented, does not use electrodes and the electric current is induced by a varying magnetic field (21).…”

Section: Procedures For Macroscopic Electrical Measurements (Electricamentioning

confidence: 99%

“…Figura 3. a) y b) Representación de la variación de la resistividad ρ con la edad de curado para los diversos especímenes de mortero (escala semi-logarítmica), c) velocidad de la resistividad con la edad de curado. (17). El valor de ρ en los morteros depende de la porosidad abierta y de la solución del poro, sin embargo la variación debida a la resistividad de solución de poro únicamente afecta en la primera hora de hidratación (25).…”

Section: Electrical Resistivity (ρ ρ)unclassified

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Evaluación de las propiedades eléctricas de morteros de cemento con puzolanas

Cruz¹,

Payá²,

Lalinde³

et al. 2010

Mater. construcc.

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RESUMENEn este trabajo se analiza la microestructura de morteros de cemento Portland, mediante medidas de impedancia eléctrica. Se comparan morteros de cemento sin y con dos sustituciones puzolánicas: residuo de catalizador de craqueo catalítico (FCC) y metacaolín (MK). Se describe el método de medida y se desarrolla el modelo de análisis de los espectros de impedancia eléctrica. Se definen tres parámetros eléctricos: resistividad eléc-trica, exponente capacitivo y factor capacitivo. Se observa un aumento importante de la resistividad de los morteros con puzolana a partir de los 7 días de curado, sobre todo en morteros con MK. Este aumento está correlacionado con la fijación de cal de las puzolanas. Las propiedades capacitivas son diferentes a edad temprana, pero se igualan a los 148 días. Los resultados eléctricos y mineralógicos muestran que la evolución microestructural comienza antes en los morteros con MK que con FCC y que la microestructura final es diferente.Palabras clave: adición activa, análisis térmico, hidratación, hidróxido cálcico, impedancia eléctrica. SUMMARYIn this paper the evolution of the microstructure of Portland cement mortar is analyzed, by using electrical impedance measurements. Cement mortars are compared without and with two pozzolanic substitutions: spent fluid catalytic cracking catalyst (FCC) and metakaolin (MK). The measurement method is described and the model for analyzing the electrical impedance spectra is developed. Three electrical parameters are defined: electrical resistivity, capacitance exponent, and capacitive factor. The results show a significant increase in resistivity of the mortars with pozzolans after 7 days of curing, especially in mortars with MK. This increase is correlated with lime-fixing by the pozzolans. The capacitive properties evolve differently at early age, but reach the same values after 148 days. The electrical and mineralogical data show that the evolution of the microstructure in the mortar with MK starts before it does in the mortars with FCC and that the final microstructure becomes different.

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Electrical conductivity, diffusion, and permeability of Portland cement-based mortars

Cited by 167 publications

References 21 publications

Electrical Conductivity and Chloride Ingress in Hardened Cement Paste

Electrical Conductivity and Chloride Ingress in Hardened Cement Paste

Efeito da escória de alto forno na resistividade elétrica superficial do concreto

Evaluación de las propiedades eléctricas de morteros de cemento con puzolanas

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