PSI - Issue 64

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ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 64 (2024) 122–129

SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Evaluation of concrete frost resistance using drilled concrete powder SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Evaluation of concrete frost resistance using drilled concrete powder

Sothyrak Rath a , Xi Ji b , Yuya Takahashi b , Shunsei Tanaka c , Yuya Sakai d,* a Department of Civil Engineering, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan b Department of Civil Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan c Taisei Corporation, Nishi-Shinjuku 1-25-1, Shinjuku-ku, Tokyo 163-0606, Japan d Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan Sothyrak Rath a , Xi Ji b , Yuya Takahashi b , Shunsei Tanaka c , Yuya Sakai d,* a Department of Civil Engineering, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan b Department of Civil Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan c Taisei Corporation, Nishi-Shinjuku 1-25-1, Shinjuku-ku, Tokyo 163-0606, Japan d Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8505, Japan

Abstract Monitoring in-situ frost damage of concrete structures has always been a substantial challenge. Core tests are commonly used for direct evaluation of frost damage, but they affect structural integrity and are unsuitable for ongoing monitoring. Therefore, investigating on other evaluation methods that induce minimal damage is necessary. This study examines the applicability of the drilling powder method for estimating the degree of frost damage in concrete. Concrete samples were prepared using different water – cement ratios, curing conditions, and air-entrained admixture dosages. The powder samples were extracted using a 4-mm drilling bit, and the pore structures of the powder were evaluated. Their correlation with the degree of frost damage is examined. The results showed that the degree of frost damage can be evaluated based on the threshold powder porosity. These findings indicate that the proposed method can potentially be employed for minimal damage assessments of concrete structures in cold regions. © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers Keywords: Minimal damage; Frost resistance; Concrete powder; Concrete core; Porosity 1. Introduction In cold climates, internal frost damage is a major problem in concrete structures that poses a considerable challenge to engineers worldwide. Frost damage caused by recurrent freeze – thaw (F – T) cycles is a complex phenomenon; Abstract Monitoring in-situ frost damage of concrete structures has always been a substantial challenge. Core tests are commonly used for direct evaluation of frost damage, but they affect structural integrity and are unsuitable for ongoing monitoring. Therefore, investigating on other evaluation methods that induce minimal damage is necessary. This study examines the applicability of the drilling powder method for estimating the degree of frost damage in concrete. Concrete samples were prepared using different water – cement ratios, curing conditions, and air-entrained admixture dosages. The powder samples were extracted using a 4-mm drilling bit, and the pore structures of the powder were evaluated. Their correlation with the degree of frost damage is examined. The results showed that the degree of frost damage can be evaluated based on the threshold powder porosity. These findings indicate that the proposed method can potentially be employed for minimal damage assessments of concrete structures in cold regions. © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers Keywords: Minimal damage; Frost resistance; Concrete powder; Concrete core; Porosity 1. Introduction In cold climates, internal frost damage is a major problem in concrete structures that poses a considerable challenge to engineers worldwide. Frost damage caused by recurrent freeze – thaw (F – T) cycles is a complex phenomenon; © 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers

* Corresponding author. Tel.: +81-3-5452-6098. E-mail address: ysakai@iis.u-tokyo.ac.jp * Corresponding author. Tel.: +81-3-5452-6098. E-mail address: ysakai@iis.u-tokyo.ac.jp

2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers 2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers

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