Bridge Over Indian River

The Problem

The bridge is located on US-A1A near the City of Stuart, on the east coast of Florida. It consists of thirty 102 ft. long simply supported spans. Each span consists of five AASHTO Type III girders spaced at 5.5-ft. on centers with a 7 inch thick concrete deck slab. The bridge opened to traffic in 1957 and was designed to carry two lanes of AASHTO HS-15 loading.

All of the girders at the westernmost span exhibited severe signs of deterioration due to saltwater spray caused by a seawall under the span at this location. Chloride intrusion through the concrete resulted in corrosion of the bottom layer of strands at several locations and spalling of the concrete cover resulted.

Close inspection of the condition of reinforcement revealed that the strands at the bottom layer had lost over 50% of their cross section.


Typical Spalling Caused by Corrosion	Longitudinal View of Type III Girder

Load testing evaluation revealed significant deterioration in the flexural capacity of the span and required immediate attention. The level of deterioration was so severe that replacement of the entire span was considered to be the only option. The severity of the deterioration and the location of the bridge created an emergency situation.

A high strength composite carbon laminate system was considered to be a valid solution. The MAS2000 Fiber Wrap System provided the required strength and durability needed for this application. The system was considered to be very economical when compared to conventional and costly replacement methods. In addition, the system also serves as a barrier protecting the girders from future contamination by saltwater spray.

The Solution

The MAS2000 Fiber Wrap System was designed to restore full capacity of the girders. The damaged girders were first analyzed utilizing a non-linear finite element program developed by SDR engineers. The program was developed and calibrated through extensive laboratory and field testing and yields extremely accurate results. The results of the analysis were used to design the optimum restoration solution.

Corroded portions of the prestressing strands were removed and a neutralizing agent was applied to prevent future corrosion. The concrete sections were then restored to original shape using high quality concrete capable of reaching full strength within 24 hours. Girder restoration was followed by surface preparation according to SDR specifications. A specially designed composite laminate was then applied to the girders for their entire length.

The bridge, being located over water, presented a challenge to the work crew. However, the repair was completed within 96 hours during a period of five days.

After completion of the repairs, surfaces of the girders were prepared and then coated with a specially formulated polymer sealant to provide ultraviolet (UV) resistance and to resist chloride intrusion.

The MAS2000 Fiber Wrap System proved to be economical, quick and easy to apply.


Application of MAS2000 Fiber Wrap System	Rehabilitated Type III Girders

Load testing and inspection proved the structure to be sound and the original load rating for the bridge was maintained without any need for posting. Rehabilitation was completed in 1997 and the bridge has been functioning without any signs of distress or deterioration.