Effect of specimen sizes, specimen shapes, and placement directions on compressive strength of concrete

Yi, Seong‐Tae; Yang, Eun Ik; Choi, Joong-Cheol

doi:10.1016/j.nucengdes.2005.08.004

Cited by 247 publications

(93 citation statements)

References 9 publications

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“…The greater variability in results and higher mean compressive strength presented by the smaller test specimens are in line with the behaviors reported in studies on the subject [7,[17][18][19][20][21], and can be explained especially by the theory Of Effect Size [19,20]. Beyond that, it should be taken into account that the mechanical strength of a cementitious matrix composite is significantly affected by the porosity of its internal structure [21].…”

Section: Evaluation Of Resultssupporting

confidence: 88%

Characterization of test specimens produced in reduced size for X-ray microtomography (µ-CT) tests

Bernardes

Magalhães

Vasconcelos

et al. 2017

Rev. IBRACON Estrut. Mater.

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ResumoThe need to use reduced sample sizes, in order to attain improved spatial resolution in (µ-CT) tests applied in Portland cement composites, makes researchers perform the fractionation of materials to obtain samples with dimensions compatible with the capacity of the scanning equipment, which might cause alterations in the microstructure under analysis. Therefore, a test specimen (TS) with dimensions compatible with the scanning capacity of a microtomography system that operates with an X-ray tube and voltage ranging from 20 to 100 kV was proposed. Axial compression strength tests were made and their total porosity was assessed by an apparent density and solid fraction density ratio, which were obtained by means of mercury and helium pycnometry and µ-CT technique, respectively. The adoption of that TS has shown to be viable for providing a sample with a higher level of representation.Keywords: X-ray microtomography, fractionation of samples, test specimen, pycnometry, pore structure.A necessidade de se utilizar amostras de tamanho reduzido, para a obtenção de uma melhor resolução espacial nos ensaios de µ-CT em compósitos de cimento Portland, leva os pesquisadores a realizar o fracionamento do material para a obtenção de amostras com dimensões compatíveis com a capacidade de leitura do equipamento, o que pode ocasionar alterações da microestrutura em análise. Assim, foi proposto um corpo de prova (CP) com dimensões compatíveis com a capacidade de leitura de um microtomógrafo com tubo de raios X que opera dentro de um intervalo de tensão de 20 a 100 kV.Foram realizados testes de resistência à compressão axial e avaliação da sua porosidade total por meio da relação entre a densidade aparente e a densidade da fração sólida, obtidas respectivamente pelas técnicas de picnometria (de mercúrio e hélio) e pela técnica de µ-CT. A adoção deste CP se mostrou viável por proprocionar uma amostragem com maior nível de representatividade.Palavras-chave: microtomografia de raios X; fracionamento de amostras, corpo de prova, picnometria, estrutura de poros.

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Section: Evaluation Of Resultssupporting

confidence: 88%

Characterization of test specimens produced in reduced size for X-ray microtomography (µ-CT) tests

Bernardes

Magalhães

Vasconcelos

et al. 2017

Rev. IBRACON Estrut. Mater.

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show abstract

“…By reducing the effective cross-sectional area difference between cube (prism) and cylinder during testing, a useful comparison can be made on the effect of specimen shape to its compressive strength [5]. The initial target cross-sectional area for cylinder was a 45mm diameter (1590mm 2 ), compared with 40 x 40mm (1600mm 2 ) cube.…”

Section: Resultsmentioning

confidence: 99%

Effect of Specimen Shape and Size on the Compressive Strength of Foamed Concrete

Sudin

Ramli

2014

MATEC Web of Conferences

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-Lightweight concrete, in the form of foamed concrete, is a versatile material that primarily consists of a cement based mortar, mixed with at least 20% volume of air. Its dry density is typically below 1600 kg/m 3 with a maximum compressive strength of 15MPa. The ASTM standard provision specifies a correction factor for concrete strength of between 14 and 42Mpa, in order to compensate for a reduced strength, when the aspect height-to-diameter ratio of a specimen is less than 2.0. However, the CEB-FIP provision specifically mentions a ratio of 150mm dia. x 300mm cylinder strength to 150 mm cube strength; though, both provision requirements do not specifically clarify the applicability and/or modification of the correction factors for the compressive strength to lightweight concrete (in this case, foamed concrete). The focus of this work is to study the effect of specimen size and shape on the axial compressive strength of concrete. Specimens of various sizes and shapes were cast with square and circular cross-sections i.e., cubes, prisms, and cylinders. Their compression strength behaviours at 7 and 28 days were investigated. The results indicate that, as the CEB-FIP provision specified, even for foamed concrete, 100mm cubes (l/d = 1.0) produce a comparable compressive strength with 100mm dia. x 200mm cylinders (l/d = 2.0).

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“…However, in this paper, the uniaxial compressive strength is measured from the 150 mm cube specimen fc150. For ordinary strength concrete, this relationship is approximately fc'=0.9 fc150 (Yi et al, 2006).…”

Section: Model Verification and Analysismentioning

confidence: 98%

Study of the anti-penetration performance of concrete with different coarse aggregate content

Wu¹,

Li²,

Shen³

2018

Lat. Am. j. solids struct.

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Deep penetration experiments were performed on five types of concrete with different coarse aggregate content. The projectile diameter was 29.9 mm, the initial velocity was 647 m/s, and the volume fraction of the coarse aggregate was between 0% and 59.0%. The damage laws and damage mechanism of the target were analyzed. The pure mortar target had the smallest radial crack origin diameter and crater depth. Too high of the coarse aggregate content led to the formation of many voids, which led to the disappearance of radial cracks, crater surface bypassing the coarse aggregate and a large reduction of crater diameter. The influence laws and mechanism of the coarse aggregate on the penetration depth were also analyzed. The increase of volume fraction of coarse aggregate was beneficial to reducing penetration depth and the increase of voids volume fraction was opposite. The penetration depth was the lowest when the volume fraction of the coarse aggregate reached the maximum and no voids formed. By modifying the static resistance stress in the Forrestal penetration formula, a penetration depth model considering the volume fractions of the coarse aggregate and voids was established. The predicted results were in good agreement with the experimental results.

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Effect of specimen sizes, specimen shapes, and placement directions on compressive strength of concrete

Cited by 247 publications

References 9 publications

Characterization of test specimens produced in reduced size for X-ray microtomography (µ-CT) tests

Characterization of test specimens produced in reduced size for X-ray microtomography (µ-CT) tests

Effect of Specimen Shape and Size on the Compressive Strength of Foamed Concrete

Study of the anti-penetration performance of concrete with different coarse aggregate content

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