Permeation Analysis

Basheer, P. A. M.

doi:10.1016/b978-081551437-4.50019-9

Cited by 33 publications

(42 citation statements)

References 34 publications

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“…Autoclam device from Amphora Company was used to measure the Air Permeability Index (API) [32]. The modification of the API test procedure involves applying of an annular seal, between the base ring and the concrete surface, made of microgum with a thickness of 8 mm, and also clamping a steel ring with G-clamps instead of using expansion anchors in the bored holes.…”

Section: Specimens and Test Methodsmentioning

confidence: 99%

Permeability testing of radiation shielding concrete manufactured at industrial scale

2018

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The effect of the composition of industrial concrete designed for radiation shielding structures on the air permeability and the diffusion of moisture was studied. The mix design for heavyweight concrete of bulk density 3168-3317 kg/m 3 was developed using barite and magnetite aggregate and cements blended with fly ash and blastfurnace slag. Structural elements, like columns of a height of 4 m and massive blocks made of mixtures with different cements were manufactured using ready mixed concrete pumped into the formwork. Core specimens were taken from the elements at different locations. The air permeability index was tested using Autoclam device. Evaluation of the quality of concrete on the basis of API results varied from ''very good'' to ''good''. The moisture distribution inside concrete specimens was equilibrated to RH = 60 ± 5%. Observation of RH changes allowed to determine the moisture diffusion coefficient. Significant differences of the permeability and moisture diffusion coefficient depending on the location of the core specimens drilling and mix design of concrete were found. The D coefficient provided a good reflection of the different quality of heavyweight concrete in structural elements.

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Section: Specimens and Test Methodsmentioning

confidence: 99%

Permeability testing of radiation shielding concrete manufactured at industrial scale

2018

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“…After 4 days, a further quarter of the depth was immersed before complete immersion after another 2 days. The whole process is shown in Figure 1, which allowed the specimens to be saturated by capillary action without trapping air [20]. At the completion of the saturation process, the saturated mass (Mo) and the dimensions (radius, r and length, l) were measured.…”

Section: Specimen Preparationmentioning

confidence: 99%

“…Relative humidity (RH) provides direct information about the content and distribution of moisture in the concrete sample and is considered a useful parameter in checking the reliability of an air permeability measurements; particularly when distinguishing between pore structure and moisture affects [14,16,20,21]. In this study, RH measurements were carried out on sample surfaces and within drilled 20 mm deep holes using an RH probe, which is shown in Figure 2.…”

Section: Relative Humidity On the Surface And In The 20mm Drilled Holementioning

confidence: 99%

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Establishment of a preconditioning regime for air permeability and sorptivity of alkali-activated slag concrete

Yang

Chen

Magee

et al. 2016

Cement and Concrete Composites

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This study reports an experimental investigation designed to assess the influence of near-surface moisture contents on permeation properties of alkali-activated slag concrete (AASC). Five different drying periods (5, 10, 15, 20 and 25 days) and three AASC and normal concretes with compressive strength grades ranging from C30 to C60 were considered. Assessment of moisture distribution was achieved using 100 mm diameter cores with drilled cavities. Results indicate that air permeability of AASC is very sensitive to the moisture content and its spatial distribution, especially at relative humidity above 65%. To control the influence of moisture on permeation testing, the recommendation of this paper is that AASC specimens should be dried in controlled conditions at 40 o C for 10 days prior to testing. It was also concluded from this study that AASC tends to perform less well, in terms of air permeability and sorptivity, than normal concrete for a given strength grade. This conclusion reinforces the need to further examine AASC properties prior to its widespread practical use.

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“…In concrete, physical structure (distribution and pores size) as well as water condition inside these pores, influence the transportation process (Muhammed Basheer, 2001).…”

Section: Introductionmentioning

confidence: 99%

Estudio de la adición de arcillas calcinadas en la durabilidad de hormigones

Lara

Antoni²,

Díaz

et al. 2011

Rev. ing. constr.

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Estudio de la adición de arcillas calcinadas en la durabilidad de hormigones * Universidad Central de Las Villas, Santa Clara, Cuba ** Escuela Politécnica Federal de Lausana (EPFL), SUIZA Resumen Actualmente son bien conocidas las ventajas económicas y medioambientales de la sustitución del clínker de cemento por otros materiales cementicios suplementarios. Las arcillas calcinadas en forma de metacaolín han recibido por ejemplo especial atención en años recientes. Se conoce que estas adiciones, cuando se añaden a morteros y hormigones, mejoran tanto su resistencia mecánica como su durabilidad. El objetivo de este trabajo es evaluar el comportamiento de las propiedades físico-mecánicas y la durabilidad en microhormigones, empleando arcillas calcinadas y molidas como material sustituyente del 30% en peso del cemento Pórtland ordinario (CPO). Para ello se utilizó una tierra arcillosa, compuesta principalmente por mineral caolín de bajo grado de pureza, para la obtención de arcillas calcinadas como minerales cementicios suplementarios. Los mejores resultados se resistencia a la compresión a los 28 días se obtuvieron para la arcilla sedimentada y calcinada, la cual posee mayor contenido de mineral caolín debido a un proceso de purificación por sedimentación de la materia prima acometido sólo para esta adición. Sin embargo, los ensayos de absorción de agua por capilaridad arrojaron los mejores resultados para el suelo arcilloso calcinado, el cual posee una elevada finura en comparación al resto de los materiales estudiados. Los menores valores mostrados por esta adición, tanto de porosidad capilar como de sorptividad, indican que existió un predominio del fenómeno de la compacidad e impermeabilidad, lograda en la matriz cementicia al usar un material tan fino, por encima del efecto de la reacción puzolánica. Estudios en la microestructura del gel de C-S-H, usando energía dispersiva por rayos-X (EDX), demostraron como el empleo de arcillas calcinadas en sustitución del CPO favorece la formación de productos de hidratación más estables, principalmente monosulfos del tipo hemicarbo y monocarbo, lo cual es conveniente para el hormigón ante la posible acción de diferentes mecanismos de degradación.Palabras Clave: Arcillas calcinadas, durabilidad, absorción capilar, porosidad, productos de hidratación Abstract Currently economical and environmental advantages of cement clinker replacement by other supplementary cementious materials are well known. For example calcined clays, such as metakaolin, have drawn special attention during recent years. It is well known that these admixtures added to mortars and concretes improve mechanical strength as well as durability. The purpose of this study is to evaluate the behavior of physical-mechanical properties and durability in micro-concretes, by employing calcinated and grinded clays as replacement material, by 30% of ordinary Portland cement (OPC). Therefore, clay soil was employed, which is mainly composed by low-purity-kaolin mineral, so as to obtain calcined clays to be used as s...

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Permeation Analysis

Cited by 33 publications

References 34 publications

Permeability testing of radiation shielding concrete manufactured at industrial scale

Permeability testing of radiation shielding concrete manufactured at industrial scale

Establishment of a preconditioning regime for air permeability and sorptivity of alkali-activated slag concrete

Estudio de la adición de arcillas calcinadas en la durabilidad de hormigones

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