An improved ring test to assess cracking resistance of concrete under restrained shrinkage

Nowadays, low water-to-cement (w/c) ratio has been put into widespread use in engineering practice. However, low w/c ratio may give rise to high self-desiccation, which may lead to the decrease of early-age cracking resistance. Investigating the impact of w/c ratio on cracking resistance is utterly meaningful to understand the cracking mechanism of concrete better. However, the corresponding investigations remain lacking, especially when the ring test is utilized. Ring tests for three concrete mixtures with different w/c ratios were conducted to investigate the early-age cracking resistance of concrete from multiple parameters in the present study. Results showed that: (1) the development rate of shrinkage of concrete for Mixture W50 was slower than Mixture W33 and W40; (2) the value and development rate of residual stress of concrete decreased when the w/c ratio increased; (3) the relaxed stress for all mixtures developed rapidly at very early age, and reached the maximum quickly; (4) the cracking resistance of concrete increased as the w/c ratio increased at early age.

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Restrained Shrinkage Behavior of Concrete under Different Environmental Conditions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.941-944.835 ◽

2014 ◽

Vol 941-944 ◽

pp. 835-841 ◽

Cited By ~ 1

Author(s):

Zhi Tao Chen ◽

Mao Guang Li ◽

Ying Zi Yang ◽

Qi Liu

Keyword(s):

Relative Humidity ◽

Environmental Conditions ◽

Test Method ◽

Mineral Admixtures ◽

Ring Test ◽

Test Duration ◽

Restrained Shrinkage ◽

Shrinkage Cracking ◽

Higher Temperature ◽

Shrinkage Behavior

The ring test method is used to evaluate the behavior of concrete under restrained shrinkage. Four kinds of environmental conditions (20±1°C, RH60±5%; 35±1°C, RH60±5%; 50±1°C, RH15±5%; 65±1°C, RH15±5%) were designed to investigate the effect the environmental condition on the shrinkage behavior of concrete prepared with different kinds of mineral admixtures. The results show that higher temperature and lower relative humidity can increase the risk of shrinkage cracking. The addition of different mineral admixtures increases the shrinkage of concrete at room conditions. In the case of higher temperature and lower relative humidity, the addition of mineral admixtures can delay the shrinkage cracking in the test duration.

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Development of notched ring test for measuring slow cracking resistance in plastics pipes and fittings

Plastics Rubber and Composites ◽

10.1179/174328907x191314 ◽

2007 ◽

Vol 36 (5) ◽

pp. 219-225 ◽

Cited By ~ 8

Author(s):

S. Choi ◽

S. Pyo ◽

Y. S. Suh ◽

Y. Seo

Keyword(s):

Ring Test ◽

Cracking Resistance

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Thermoplastics pipes for the conveyance of fluids. Determination of the slow cracking resistance of pipes and fittings using the Notched Ring Test (NRT)

10.3403/30249478 ◽

2012 ◽

Keyword(s):

Ring Test ◽

Cracking Resistance

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Notched Ring Test for Measuring Slow Cracking Resistance in Plastics Pipes and Fittings

Macromolecular Symposia ◽

10.1002/masy.201051082 ◽

2010 ◽

Vol 296 (1) ◽

pp. 626-631 ◽

Cited By ~ 4

Author(s):

Christian Tischler ◽

Thomas R. Kratochvilla ◽

Heinz Muschik ◽

Heinz Dragaun

Keyword(s):

Ring Test ◽

Cracking Resistance

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Restrained Shrinkage Ring Test on Polymer Fibres Treated in Cold Plasma Discharge

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.464.25 ◽

2013 ◽

Vol 464 ◽

pp. 25-30 ◽

Cited By ~ 1

Author(s):

Daniel Kopkáně ◽

Lenka Bodnárová ◽

Rudolf Hela

Keyword(s):

Low Temperature ◽

Cold Plasma ◽

Plasma Discharge ◽

Ring Test ◽

Cement Matrix ◽

Restrained Shrinkage ◽

Low Temperature Plasma ◽

Polypropylene Fibres ◽

Temperature Plasma ◽

Positive Correlation

The paper refers to utilization of low temperature plasma discharge in air on polypropylene fibres. Such fibres have been tested in concrete as reinforcement. The effect has been tested by restrain ring test. The experiment proved positive correlation between time of exposure and cracks suppression. The effect is considered as improved cohesion of polymer fibres with cement matrix.

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An Evaluation on the Restrained Shrinkage of Ultra-High Performance Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.525-526.449 ◽

2012 ◽

Vol 525-526 ◽

pp. 449-452 ◽

Cited By ~ 1

Author(s):

Jung Jun Park ◽

Doo Yeol Yoo ◽

Sung Wook Kim ◽

Young Soo Yoon

Keyword(s):

High Performance ◽

High Performance Concrete ◽

Tensile Creep ◽

Ring Test ◽

Early Age ◽

Restrained Shrinkage ◽

Reinforcing Bars ◽

Ultra High Performance Concrete ◽

Shrinkage Cracking ◽

Coarse Aggregates

Since ultra-high performance concrete (UHPC) is subject to large occurrence of shrinkage at early age due to its low water-to-cement ratio, the mixing of large quantities of powdered admixtures and the absence of coarse aggregates, UHPC presents large risks of shrinkage cracking caused by the restraints provided by the form and reinforcing bars. Accordingly, this study intends to evaluate the shrinkage behavior of UHPC under restrained state by performing restrained shrinkage test using ring-test. The test results reveal that increasing thickness of the inner ring increases the tensile creep at early age leading to the reduction of the average strain and residual stress of the inner ring.

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