Dimensional and ice content changes of hardened concrete at different freezing and thawing temperatures

Publication: Research - peer-reviewJournal article – Annual report year: 2010

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Dimensional and ice content changes of hardened concrete at different freezing and thawing temperatures. / Johannesson, Björn.

In: Cement and Concrete Composites, Vol. 32, No. 1, 2010, p. 73-83.

Publication: Research - peer-reviewJournal article – Annual report year: 2010

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Johannesson, Björn / Dimensional and ice content changes of hardened concrete at different freezing and thawing temperatures.

In: Cement and Concrete Composites, Vol. 32, No. 1, 2010, p. 73-83.

Publication: Research - peer-reviewJournal article – Annual report year: 2010

Bibtex

@article{f7d222ec60b447a6ba6739cb32011d13,
title = "Dimensional and ice content changes of hardened concrete at different freezing and thawing temperatures",
keywords = "Durability, Freezing, Frost damages, Scanning calorimeter, Ice content, Thawing",
publisher = "Pergamon",
author = "Björn Johannesson",
year = "2010",
doi = "10.1016/j.cemconcomp.2009.09.001",
volume = "32",
number = "1",
pages = "73--83",
journal = "Cement and Concrete Composites",
issn = "0958-9465",

}

RIS

TY - JOUR

T1 - Dimensional and ice content changes of hardened concrete at different freezing and thawing temperatures

A1 - Johannesson,Björn

AU - Johannesson,Björn

PB - Pergamon

PY - 2010

Y1 - 2010

N2 - Samples of concrete at different water-to-cement ratios and air contents subjected to freeze/thaw cycles with the lowest temperature at about -80 degrees C are investigated. By adopting a novel technique, a scanning calorimeter is used to obtain data from which the ice contents at different freeze temperatures can be calculated. The length change caused by temperature and ice content changes during test is measured by a separate experiment using the same types of freeze-thaw cycles as in the calorimetric tests. In this way it was possible to compare the amount of formed ice at different temperatures and the corresponding measured length changes. The development of cracks in the material structure was indicated by an ultra-sonic technique by measuring on the samples before and after the freeze-thaw tests. Further the air void structure was investigated using a microscopic technique in which air'bubble' size distributions and the so-called spacing factor, indicating the mean distance between air bubbles, were measured. By analyzing the experimental result, it is concluded that damages occur in the temperature range of about -10 degrees C to -55 degrees C, when the air content is lower than about 4% of the total volume. For a totally water-saturated concrete, damages always occur independently of the use of entrained air or low water-to-cement ratios. It is, further, concluded that the length changes of these samples correspond to the Calculated ice contents at different temperatures in a linear fashion. @ 2009 Elsevier Ltd. All rights reserved.

AB - Samples of concrete at different water-to-cement ratios and air contents subjected to freeze/thaw cycles with the lowest temperature at about -80 degrees C are investigated. By adopting a novel technique, a scanning calorimeter is used to obtain data from which the ice contents at different freeze temperatures can be calculated. The length change caused by temperature and ice content changes during test is measured by a separate experiment using the same types of freeze-thaw cycles as in the calorimetric tests. In this way it was possible to compare the amount of formed ice at different temperatures and the corresponding measured length changes. The development of cracks in the material structure was indicated by an ultra-sonic technique by measuring on the samples before and after the freeze-thaw tests. Further the air void structure was investigated using a microscopic technique in which air'bubble' size distributions and the so-called spacing factor, indicating the mean distance between air bubbles, were measured. By analyzing the experimental result, it is concluded that damages occur in the temperature range of about -10 degrees C to -55 degrees C, when the air content is lower than about 4% of the total volume. For a totally water-saturated concrete, damages always occur independently of the use of entrained air or low water-to-cement ratios. It is, further, concluded that the length changes of these samples correspond to the Calculated ice contents at different temperatures in a linear fashion. @ 2009 Elsevier Ltd. All rights reserved.

KW - Durability

KW - Freezing

KW - Frost damages

KW - Scanning calorimeter

KW - Ice content

KW - Thawing

U2 - 10.1016/j.cemconcomp.2009.09.001

DO - 10.1016/j.cemconcomp.2009.09.001

JO - Cement and Concrete Composites

JF - Cement and Concrete Composites

SN - 0958-9465

IS - 1

VL - 32

SP - 73

EP - 83

ER -