Application of FRP composites for underwater piles repair

SP-230: 7th International Symposium on Fiber-Reinforced (FRP) Polymer Reinforcement for Concrete Structures, 2005

Synopsis: The poor durability of conventional corrosion repairs has led to increased interest for its replacement by fiber reinforced polymers (FRP). Over the past decade, several highway agencies completed demonstration projects in which FRP was used to repair corrosion damage on surfaces that were dry. These repairs have held up well and show little sign of deterioration. The availability of resins that can cure in water has made it possible to explore the application of FRP for the underwater repair of corrosion-damaged piles. This paper presents findings from three demonstration projects in which corroding reinforced and prestressed piles at two contrasting locations were repaired using two different FRP systems. Several piles were instrumented to allow long-term corrosion monitoring. The projects confirm the feasibility of conducting underwater FRP repairs in tidal waters. Preliminary data suggests that the wrap leads to a reduction in the prevailing corrosion rate.

NCHRP-IDEA Program Project Final Report, 2010

This Innovations Deserving Exploratory Analysis (IDEA) project developed a new fiber reinforced polymer (FRP) repair system incorporating a sacrificial cathodic protection (CP) system inside a FRP wrap. The FRP-CP system is versatile and can be used for repairing concrete columns or piles in seismic or non-seismic regions, on dry land or partially submerged in salt water. The system was implemented for repairing piles in estuarine waters and its effectiveness over the duration of the project proven. The project was carried out in two separate stages. In the first stage, pressure / vacuum bagging technologies commonly used by the composite industry for bonding composite elements were refined to develop a new system suitable for infrastructure applications. This new system assured good bond between concrete and FRP, irrespective of the wetness or dryness of the concrete surface; tests showed that compared to controls, pressure bagging improved bond by over 70% and vacuum bagging by ov...

Fiber reinforced polymers (FRP) have been used extensively for repairing and rehabilitating structures for well over a decade. Its application for strengthening corrosion-damaged reinforced concrete elements is of more recent origin. Several state transportation departments such as Michigan, New York and Texas have carried out demonstration projects using FRP for repairing corrosion damage. Recently, the Florida Department of Transportation funded studies to evaluate the application of FRP for repairing corrosion damaged prestressed piles driven in tidal waters. This paper provides a brief overview of some of the findings and discusses design, experimentation and implementation issues.

Transportation Research Record: Journal of the Transportation Research Board, 2007

The poor durability of conventional repairs has led to increased interest in the application of fiber-reinforced polymers (FRP) for repairing corroded concrete structures. The availability of resins that can cure under wet conditions has made it possible to consider FRP for repairing partially submerged piles. An overview is provided of a recently completed multiyear study that investigated this problem. In the project, laboratory studies were conducted to determine the effectiveness of FRP in corrosion repair, and two field demonstration projects were completed. A simple, new design method was developed and used for the design of the FRP wrap in the demonstration projects. Some of the issues related to pile repair are addressed, with particular attention to the newly developed design method.

Journal of Performance of Constructed Facilities, 2005

An effective method for combined environmental protection and structural restoration of wood piles in waterfront facilities is not available. The objective of the study presented in this paper is to survey the available methods for wood pile protection and structural restoration with the intent of developing an effective method. In addition to reviewing the available repair methods, a field inspection of a harbor in Maine was conducted to assess existing technologies. A wood pile repair method that utilizes bonded fiber-reinforced polymer (FRP) composite shells and a grouting material is proposed. Fiber, resin, adhesive, coating, and grouting materials are systematically analyzed to deliver the required system performance. Two fabrication methods for the FRP composite shells are discussed based on the experience gained in the fabrication of laboratory prototypes. Then a step-by-step procedure amenable for field installation is proposed, and a preliminary cost analysis is conducted to assess the feasibility of the proposed system.

2022

The development of the use of advance composites is remarkable, especially in applications that require the materials used to be corrosion resistant. One of the most important of these applications is the structures built inside or under water, especially hydraulic structures. Constant exposure to wet makes materials such as concrete and steel threatened to the high level of corrosion and deterioration. The traditional methods for repairing proved insufficient over time, in addition to being expensive in some cases. Therefore, it became necessary to search for alternatives that achieve engineering efficiency and lower costs. One of these alternatives is the use of fiber reinforced polymer (FRP) system. Until recent years, it was not possible to use FRP system under water as a repair system for hydraulic structures without cofferdam. However, during this period, types of underwater cured resins were produced and underwater FRP system is the best choice for this type of structures. There are no many practical applications for the use of FRP in repairing of hydraulic structures, so it is possible to study its application in marine structure to show the possibility of use it in hydraulic structure. This research highlight the advantages and disadvantages of traditional method in repairing underwater structures. Also present project that considered the underwater FRP as a construction material used in the rehabilitation of deteriorated concrete pile. As a conclusion, using fibers with water activated resin can provide an economical solution for future repair and rehabilitation projects. Also the pre-preg system is efficient for repairing dry zones, while the wet layup system is very effective in repairing splash zones of damaged structural elements.

The high cost of infrastructure repair due to corrosion of steel has led to a worldwide interest in the feasibility of using alternative fiber reinforced polymer (FRP) material. FRPs have long been used by the aerospace industry where it enjoys an excellent reputation for corrosion resistance. Whether such a reputation is justified for civil engineering applications remains to be fully established. Over the past decade, the University of South Florida has conducted a number of long-term studies to assess the likely performance of FRP material used for prestressing piles driven in a marine environment. In the investigations aramid, carbon, fiberglass -all identified as suitable for prestressing applications -were tested. The studies attempted to obtain answers to the following questions: Are FRP materials durable in concrete Do they become more brittle with age and exposure Does the bond between concrete and FRP deteriorate with exposure Does the polymer matrix deteriorate in concrete Most importantly, how do these changes collectively impact the strength and serviceability of FRP pretensioned elements This paper describes the basis, scope and methodology adopted in the investigations and summarizes some of the principal findings.

Engineering Science and Technology, an International Journal

Fibre reinforced polymer (FRP) composites have attracted significant attention in repairing existing and deteriorating structures since the traditional rehabilitation techniques have several limitations in terms of durability, self-weight and complex installation process. Prefabricated FRP composite jackets are the preferred solution in repairing bridge piles located both underwater and above the waterline as they can be easily placed around the damaged pile to form a robust single-piece repair system. The structural continuity of the jacket in such a repair system is critical for effectively utilising its maximum strength. This study presents an extensive review of the current practices and new opportunities for using prefabricated composite jackets for structural repair. Important design considerations to effectively utilise prefabricated FRP composite jackets in repairing structures are presented and analysed. The review also identifies the challenges and highlights the future directions of research to increase the acceptance and use of emerging composite repair systems.

Structural Engineering International, 2017

Transportation Research Record: Journal of the Transportation Research Board, 2010

Fiber-reinforced polymers (FRPs) are increasingly being used for corrosion repair. As barrier elements, FRPs can only slow down corrosion. Cathodic protection (CP) is the only proven method for stopping electrochemical corrosion of steel. But a new method repairs corrosion damage: a sacrificial CP system is incorporated within an FRP repair. The system was implemented in a demonstration project in which corroding piles supporting the Friendship Trail Bridge, Tampa Bay, Florida, were repaired. The repaired piles were instrumented so that performance of the CP system could be assessed. Results indicate that the CP system is effective in protecting the reinforcing steel. It also shows that corrosion rates are lower in FRP-wrapped piles. This lower rate can increase the life of anodes used by the CP system by more than 20%.