PSI - Issue 62

Available online at www.sciencedirect.com

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2022) 000–000 Available online at www.sciencedirect.com ScienceDirect

ScienceDirect ScienceDirect

www.elsevier.com/locate/procedia

Structural Integrity Procedia 00 (2022) 000–000

Procedia Structural Integrity 62 (2024) 285–298

www.elsevier.com/locate/procedia

II Fabre Conference – Existing bridges, viaducts and tunnels: research, innovation and applications (FABRE24) II Fabre Conference – Existing bridges, viaducts and tunnels: research, innovation and applications (FABRE24) Corrosion and brittle fracture of high strength steel in prestressed concrete structures: a critical review of the problem Corrosion and brittle fracture of high strength steel in prestressed concrete structures: a critical review of the problem Edoardo Proverbio *

University of Messina, Dept. Engineering, C/Da di Dio, 98168 Messina, Italy

Edoardo Proverbio *

Abstract

University of Messina, Dept. Engineering, C/Da di Dio, 98168 Messina, Italy

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 Scientific Board Members 10.1016/j.prostr.2024.09.044 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 Scientific Board Member s 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 Scientific Board Member s The introduction of the prestressing technique in the design of reinforced concrete structures is certainly one of the most surprising advances in construction technology which has triggered a real wave of innovation in the construction of bridges, building and, more generally, large-span structures. Given the extreme importance of the prestressing elements, great attention was addressed from the beginning to a good corrosion protection (ACI-ASCE Joint Committee 323, 1958). In post-tensioned reinforced concrete structures, protection is guaranteed by the grout (cement mixture with specific rheological properties and very low shrinkage) used to fill the cable housing ducts. The presence of grouting defects often leads to the activation of corrosion phenomena. The main problem is the presence of an aqueous phase rich in salts which can have a variable origin. Water can access grout defects due to leaks in the ducts and because of the ingress of rainwater, seawater, * * Corresponding author. Tel.: +30 090 676 5243 E-mail address: eproverbio@unime.it * * Corresponding author. Tel.: +30 090 676 5243 E-mail address: eproverbio@unime.it Abstract Corrosion of high-strength steel (wire, strand, bars, etc.) for prestressed concrete structures always raises a great concern in builders as well as in structure owners. Corrosion can occur in service due to improper protection, construction defects, improper design, and unsuitable materials or improper steel element storage before construction. Corrosion can lead, because of a significant cross-section reduction and the high load, to the failure of the prestressing steel element. However, brittle fracture, the most significant and dreaded event, can also occur when a limited corrosion attack is observed. Brittle fracture is a consequence of different damage mechanisms, and it is strongly dependent on the type of steel element. Starting from a critical analysis of the theoretical aspects and from a literature review, a comprehensive framework for correctly approaching the problem is reported. © 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 Scientific Board Members Corrosion of high-strength steel (wire, strand, bars, etc.) for prestressed concrete structures always raises a great concern in builders as well as in structure owners. Corrosion can occur in service due to improper protection, construction defects, improper design, and unsuitable materials or improper steel element storage before construction. Corrosion can lead, because of a significant cross-section reduction and the high load, to the failure of the prestressing steel element. However, brittle fracture, the most significant and dreaded event, can also occur when a limited corrosion attack is observed. Brittle fracture is a consequence of different damage mechanisms, and it is strongly dependent on the type of steel element. Starting from a critical analysis of the theoretical aspects and from a literature review, a comprehensive framework for correctly approaching the problem is reported. Keywords : corrosion, prestressing steel, hydrogen embrittlement, stress corrosion cracking 1. Introduction The introduction of the prestressing technique in the design of reinforced concrete structures is certainly one of the most surprising advances in construction technology which has triggered a real wave of innovation in the construction of bridges, building and, more generally, large-span structures. Given the extreme importance of the prestressing elements, great attention was addressed from the beginning to a good corrosion protection (ACI-ASCE Joint Committee 323, 1958). In post-tensioned reinforced concrete structures, protection is guaranteed by the grout (cement mixture with specific rheological properties and very low shrinkage) used to fill the cable housing ducts. The presence of grouting defects often leads to the activation of corrosion phenomena. The main problem is the presence of an aqueous phase rich in salts which can have a variable origin. Water can access grout defects due to leaks in the ducts and because of the ingress of rainwater, seawater, 1. Introduction Keywords : corrosion, prestressing steel, hydrogen embrittlement, stress corrosion cracking