<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-04-17T20:59:23Z</responseDate><request verb="GetRecord" identifier="oai:riubu.ubu.es:10259/10073" metadataPrefix="xoai">https://riubu.ubu.es/oai/request</request><GetRecord><record><header><identifier>oai:riubu.ubu.es:10259/10073</identifier><datestamp>2025-01-30T01:05:48Z</datestamp><setSpec>com_10259_4809</setSpec><setSpec>com_10259_5086</setSpec><setSpec>com_10259_2604</setSpec><setSpec>col_10259_4810</setSpec></header><metadata><metadata xmlns="http://www.lyncode.com/xoai" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.lyncode.com/xoai http://www.lyncode.com/xsd/xoai.xsd">
<element name="dc">
<element name="contributor">
<element name="author">
<element name="none">
<field name="value">González Cabrera, Dorys Carmen</field>
<field name="authority">246</field>
<field name="confidence">600</field>
<field name="orcid_id">0000-0001-8740-120X</field>
<field name="value">Mena Alonso, Álvaro</field>
<field name="authority">721</field>
<field name="confidence">600</field>
<field name="orcid_id">0000-0002-4269-5299</field>
<field name="value">Mínguez Algarra, Jesús</field>
<field name="authority">369</field>
<field name="confidence">600</field>
<field name="orcid_id">0000-0003-0569-5131</field>
<field name="value">Vicente Cabrera, Miguel Ángel</field>
<field name="authority">574</field>
<field name="confidence">600</field>
<field name="orcid_id">0000-0002-9425-6087</field>
</element>
</element>
</element>
<element name="date">
<element name="accessioned">
<element name="none">
<field name="value">2025-01-29T12:40:13Z</field>
</element>
</element>
<element name="available">
<element name="none">
<field name="value">2025-01-29T12:40:13Z</field>
</element>
</element>
<element name="issued">
<element name="none">
<field name="value">2021-12</field>
</element>
</element>
<element name="embargoEndDate">
<element name="none"/>
</element>
</element>
<element name="identifier">
<element name="issn">
<element name="none">
<field name="value">0165-232X</field>
</element>
</element>
<element name="uri">
<element name="none">
<field name="value">http://hdl.handle.net/10259/10073</field>
</element>
</element>
<element name="doi">
<element name="none">
<field name="value">10.1016/j.coldregions.2021.103397</field>
</element>
</element>
</element>
<element name="description">
<element name="abstract">
<element name="en">
<field name="value">In this work, the effects caused by both the amount of air-entraining agent (AEA) and freeze-thaw cycles on microstructure of high-strength concrete have been analyzed. For this purpose, five series of concrete specimens have been manufactured, each of them containing a different amount of AEA. Then, all series have been subjected to up to 300 freeze-thaw cycles. In addition, the specimens have been analyzed using a computed tomography (CT) scan device at pre-defined freeze-thaw cycles and all data have been processed with digital image processing (DIP) software.&#xd;
The results reveal, on the one hand, that the quantity of AEA has a greater influence on pore structure, and additionally the freeze-thaw action only slightly modifies the pore structure. As AEA increases, a progressive rise of the porosity and the number of pores is observed up to a maximum value. Next, a decrease is noticed. Moreover, there is not a linear relation between porosity and AEA. Furthermore, as AEA increases, a variation of its size and shape is observed. Alternatively, the effect of freeze-thaw cycles is more complex and does not show a monotonous tendency. The results reveal that the first 50 freeze-thaw cycles have the strongest influence on pore structure, observing a decrease in porosity. For the rest of the cycles, the porosity increases progressively resulting, after 300 freeze-thaw cycles, in a slightly lower porosity in almost all series than in those presented at the beginning. Hydration of unhydrated cement particles alongside with microcracking act as opposite performances during the freeze-thaw cycles. Therefore, this can suggest that, under these conditions, freeze-thaw action is not able to damage significantly the microstructure of concrete.&#xd;
The results show that the series with a lower AEA content show a better behavior under freeze-thaw cycles. In this case, the specimens exhibit a lower porosity and a higher level of small pores, and the pores evince a more elongated shape. All these features lead to a more impermeable concrete and, therefore, with a better performance under freeze-thaw cycles.</field>
</element>
</element>
<element name="sponsorship">
<element name="en">
<field name="value">The authors are grateful for the financial support from the Ministerio de Economía y Competitividad, PID2019-110928RB-C32, Spain.</field>
</element>
</element>
</element>
<element name="format">
<element name="mimetype">
<element name="none">
<field name="value">application/pdf</field>
</element>
</element>
</element>
<element name="language">
<element name="iso">
<element name="es">
<field name="value">eng</field>
</element>
</element>
</element>
<element name="publisher">
<element name="es">
<field name="value">Elsevier</field>
</element>
</element>
<element name="relation">
<element name="ispartof">
<element name="es">
<field name="value">Cold Regions Science and Technology. 2021, V. 192, 103397</field>
</element>
</element>
<element name="publisherversion">
<element name="es">
<field name="value">https://doi.org/10.1016/j.coldregions.2021.103397</field>
</element>
</element>
<element name="projectID">
<element name="es">
<field name="value">info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-110928RB-C32/ES/DAÑO A FATIGA ALTERNA EN HORMIGON DE MUY ALTA RESISTENCIA A TRACCION REFORZADO CON FIBRAS. MAPEO Y CUANTIFICACION DEL DAÑO CON TOMOGRAFIA COMPUTERIZADA/</field>
</element>
</element>
</element>
<element name="rights">
<element name="*">
<field name="value">Attribution-NonCommercial-NoDerivatives 4.0 Internacional</field>
</element>
<element name="uri">
<element name="*">
<field name="value">http://creativecommons.org/licenses/by-nc-nd/4.0/</field>
</element>
</element>
<element name="accessRights">
<element name="es">
<field name="value">info:eu-repo/semantics/openAccess</field>
</element>
</element>
</element>
<element name="subject">
<element name="en">
<field name="value">Computed tomography</field>
<field name="value">Air-entraining agent</field>
<field name="value">Freeze-thaw cycles</field>
<field name="value">High-strength concrete</field>
<field name="value">Pore structure</field>
<field name="value">Pore distribution</field>
</element>
<element name="other">
<element name="es">
<field name="value">Ingeniería civil</field>
<field name="value">Materiales de construcción</field>
<field name="value">Resistencia de materiales</field>
</element>
<element name="en">
<field name="value">Civil engineering</field>
<field name="value">Building materials</field>
<field name="value">Strength of materials</field>
</element>
</element>
</element>
<element name="title">
<element name="en">
<field name="value">Influence of air-entraining agent and freeze-thaw action on pore structure in high-strength concrete by using CT-Scan technology</field>
</element>
</element>
<element name="type">
<element name="es">
<field name="value">info:eu-repo/semantics/article</field>
</element>
<element name="hasVersion">
<element name="es">
<field name="value">info:eu-repo/semantics/acceptedVersion</field>
</element>
</element>
</element>
<element name="journal">
<element name="title">
<element name="en">
<field name="value">Cold Regions Science and Technology</field>
</element>
</element>
</element>
<element name="volume">
<element name="number">
<element name="es">
<field name="value">192</field>
</element>
</element>
</element>
<element name="page">
<element name="initial">
<element name="es">
<field name="value">103397</field>
</element>
</element>
</element>
</element>
<element name="bundles">
<element name="bundle">
<field name="name">THUMBNAIL</field>
<element name="bitstreams">
<element name="bitstream">
<field name="name">Gonzalez-crst_2021.pdf.jpg</field>
<field name="originalName">Gonzalez-crst_2021.pdf.jpg</field>
<field name="description">IM Thumbnail</field>
<field name="format">image/jpeg</field>
<field name="size">4337</field>
<field name="url">https://riubu.ubu.es/bitstream/10259/10073/4/Gonzalez-crst_2021.pdf.jpg</field>
<field name="checksum">88f449ea7fdfc6b6bf60eaa75ae14f09</field>
<field name="checksumAlgorithm">MD5</field>
<field name="sid">4</field>
</element>
</element>
</element>
<element name="bundle">
<field name="name">LICENSE</field>
<element name="bitstreams">
<element name="bitstream">
<field name="name">license.txt</field>
<field name="originalName">license.txt</field>
<field name="format">text/plain; charset=utf-8</field>
<field name="size">999</field>
<field name="url">https://riubu.ubu.es/bitstream/10259/10073/3/license.txt</field>
<field name="checksum">b295bcbce42e2caabeb0c623d3860c06</field>
<field name="checksumAlgorithm">MD5</field>
<field name="sid">3</field>
</element>
</element>
</element>
<element name="bundle">
<field name="name">CC-LICENSE</field>
<element name="bitstreams">
<element name="bitstream">
<field name="name">license_rdf</field>
<field name="originalName">license_rdf</field>
<field name="format">application/rdf+xml; charset=utf-8</field>
<field name="size">805</field>
<field name="url">https://riubu.ubu.es/bitstream/10259/10073/2/license_rdf</field>
<field name="checksum">4460e5956bc1d1639be9ae6146a50347</field>
<field name="checksumAlgorithm">MD5</field>
<field name="sid">2</field>
</element>
</element>
</element>
<element name="bundle">
<field name="name">ORIGINAL</field>
<element name="bitstreams">
<element name="bitstream">
<field name="name">Gonzalez-crst_2021.pdf</field>
<field name="originalName">Gonzalez-crst_2021.pdf</field>
<field name="description"/>
<field name="format">application/pdf</field>
<field name="size">2035119</field>
<field name="url">https://riubu.ubu.es/bitstream/10259/10073/1/Gonzalez-crst_2021.pdf</field>
<field name="checksum">47a1a8bea3a49a1b104ed28524ac8227</field>
<field name="checksumAlgorithm">MD5</field>
<field name="sid">1</field>
</element>
</element>
</element>
</element>
<element name="others">
<field name="handle">10259/10073</field>
<field name="identifier">oai:riubu.ubu.es:10259/10073</field>
<field name="lastModifyDate">2025-01-30 02:05:48.289</field>
</element>
<element name="repository">
<field name="name">Repositorio Institucional de la Universidad de Burgos</field>
<field name="mail">bubrep@ubu.es</field>
</element>
<element name="license">
<field name="bin">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</field>
</element>
</metadata></metadata></record></GetRecord></OAI-PMH>