A discussion of the paper “A neutron diffraction study of ice and water within a hardened cement paste during freeze–thaw” by I.P. Swainson and E.M. Schulson 2001. Cement and Concrete Research 31, 1821–1830

AbstractScaling of concrete due to salt frost attack is an important durability issue in moderate and cold climates. The actual damage mechanism is still not completely understood. Two recent damage theories—the glue spall theory and the cryogenic suction theory—offer plausible, but conflicting explanations for the salt frost scaling mechanism. The present study deals with the cryogenic suction theory, which assumes that freezing concrete can take up unfrozen brine from a partly frozen deicing solution during salt frost attack. According to the model hypothesis, the resulting saturation of the concrete surface layer intensifies the ice formation in this layer and causes salt frost scaling. In this study an experimental technique was developed that makes it possible to quantify to which extent brine uptake can increase ice formation in hardened cement paste (used as a model material for concrete). The experiments were carried out with low temperature differential scanning calorimetry, where specimens were subjected to freeze–thaw cycles while being in contact with NaCl brine. Results showed that the ice content in the specimens increased with subsequent freeze–thaw cycles due to the brine uptake at temperatures below 0 °C. The ability of the hardened cement paste to bind chlorides from the absorbed brine at the same time affected the freezing/melting behavior of the pore solution and the magnitude of the ice content.

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A neutron–diffraction study of changes induced in aluminous cement paste by the application of external electric fields

Physica B Condensed Matter ◽

10.1016/j.physb.2004.03.151 ◽

2004 ◽

Vol 350 (1-3) ◽

pp. E561-E564 ◽

Cited By ~ 2

Author(s):

Marta Castellote ◽

Xavier Turrillas ◽

Irene Llorente ◽

Cruz Alonso ◽

Carmen Andrade ◽

...

Keyword(s):

Neutron Diffraction ◽

Diffraction Study ◽

Electric Fields ◽

Cement Paste ◽

Neutron Diffraction Study ◽

External Electric Fields ◽

Aluminous Cement

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Composite materials based on cement matrices

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1983.0077 ◽

1983 ◽

Vol 310 (1511) ◽

pp. 191-202 ◽

Cited By ~ 5

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Cement Paste ◽

Metal Wire ◽

Hardened Cement ◽

Paper Briefly ◽

Hardened Cement Paste ◽

Recent Developments ◽

Reinforced Cement ◽

Cement And Concrete

All materials produced from inorganic hydraulic cements are composites of one kind or another because of their multiphase nature. This paper briefly considers the relevance of composite principles in predicting the mechanical properties of hardened cement paste, mortar and concrete and then discusses recent developments towards enhancing these properties by the addition of polymers and more particularly fibres. Fibres derived from glass, polypropylene and cellulose with metal wire are currently being used as cement reinforcements. Important properties of some of these practical fibre reinforced cement and concrete (F.R.C.) materials are discussed with particular reference to the replacement of asbestos products. Some examples of recent innovations in the manufacture of F.R.C. materials are given together with projections for their future use.

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