Non‐traditional assessment and maintenance methods for aging concrete structures – technical and non‐technical issues

Abstract

Based on construction dates and observed time to corrosion induced damage, the future need for repair of reinforced concrete motorway bridges in The Netherlands is predicted. Due to the age distribution and in particular the relatively short life of conventional repairs, the need for maintenance will increase steeply over the next few decades. It appears that a back log of postponed maintenance exists, which aggravates the problem. This steep rise may be mitigated by the application of various modern techniques for assessment, prevention, monitoring, and protection, that each have a good track record but are not widely used. Various factors that oppose the application of such innovations in the area of concrete maintenance are discussed.

Covercrete with hybrid functions – A novel approach to durable reinforced concrete structures

“…Another technique – cathodic protection – has been applied to reinforced concrete structures since 1970s 2, 13, 14, but to a limited extent due to relatively high costs in both installation and maintenance, as well as “psychological factors” as Polder and Peelen 3 recently pointed out.…”

“…These maintenance and rehabilitation works have a significant impact on the environment. Although cathodic protection techniques have been used in reinforced concrete structures for mitigating the corrosion problem since 1970s 2, application of such techniques is still met with considerable resistance 3. Conventionally, to prevent reinforcement from corrosion, low water–cement ratio ( w/c ) is used in concrete for reducing ingress rate of aggressive substances and large cover thickness is designed for prolonging the time for aggressive substances to reach the reinforcement steel under the specified service life.…”

Structural health monitoring with statistical methods during progressive damage test of S101 Bridge

“…Despite a general lack of experience in the time of their design, prestressed concrete was a very popular construction type in those days. Retrospectively, some of the major design assumptions proofed to be erroneous and after short periods of operation significant and characteristic damage patterns occurred at the structure [26,27]. The load bearing capacity and especially the durability of the bridges remained mostly limited despite costly retrofitting activities [28,29].…”

Protection cathodique appliquée au béton armé aérien : étude expérimentale et modélisation

“…Le processus de la corrosion en présence de chlorures est étudié par de nombreux chercheurs et ingénieurs civils depuis plus d'un demisiècle, sans déboucher sur un consensus. Le manque de compréhension fondamental est également mis en évidence par le fait que les politiques relatives aux structures corrodées diffèrent sensiblement d'un pays à l'autre (malgré la similitude du problème technique) [2], et que les stratégies d'ingénierie actuelles reposent en grande partie sur l'expérience passée et sont empiriques [2,3]. L'approche conceptuelle de l'initiation de la corrosion est basée sur la définition d'une valeur de seuil de chlorure (C crit ) qui conduirait à une dépassivation de l'acier.…”