BRIDGE REMEDIATION

Bridge Repairs, Strengthening and Concrete Protection

Bridges are exposed to traffic loads, vibration, water, road contaminants and changing weather throughout their working life. Over time, these conditions can lead to cracked concrete, reinforcement corrosion, failed joints and deterioration of structural components.

Entekra undertakes bridge remediation for councils, contractors and infrastructure asset managers. Our work covers concrete repairs, crack injection, expansion-joint replacement, protective treatments and strengthening of existing bridge components.

The scope of each project is based on the condition of the bridge and the repairs specified for the asset. Some bridges require isolated repairs to damaged concrete. Others need work across several areas to address deterioration and reduce the likelihood of the same issues returning.

Why Bridges Require Remediation

Concrete bridges are designed for long-term service, but the environment around them can be demanding. Water entering through the deck, cracks or joints can carry contaminants into the concrete. Once these reach the reinforcement, corrosion may begin.

As reinforcing steel corrodes, it expands and places pressure on the surrounding concrete. Cracks develop, sections begin to delaminate and eventually concrete can break away.

Bridge remediation may be required where there is:

• Cracked or spalling concrete

• Rust staining or exposed reinforcement

• Carbonation or chloride damage

• Water entering through cracks and joints

• Deteriorated expansion joints

• Damaged beams, columns, piers or abutments

• Loss of concrete around bridge supports

• Increasing maintenance requirements

• A need to strengthen existing components

• Protective treatments reaching the end of their working life

These issues are best addressed before deterioration moves deeper into the bridge structure and increases the amount of repair work required.

Bridge Concrete Repairs

Concrete repair is a major part of bridge remediation. Before repairs begin, loose and delaminated concrete must be located and removed. This exposes the affected reinforcement and provides a sound edge for the repair.

Where the steel has corroded, it is cleaned and treated before the concrete is reinstated. A compatible repair mortar is then applied to rebuild the damaged section and restore the required profile.

Entekra carries out concrete repairs to bridge elements including:

• Beams and crossheads

• Columns and piers

• Abutments

• Concrete supports

• Deck edges

• Parapets

• Undersides of bridge decks

• Approach and joint areas

The repair method and material are selected according to the extent of deterioration, site conditions and project specification.

Bridge Crack Injection

Cracks give water and contaminants a direct path into a concrete bridge. The appropriate treatment depends on the cause of the crack, whether movement is continuing and whether water is passing through it.

Epoxy injection can be used where the intention is to bond the separated concrete faces and restore continuity through the cracked area. Polyurethane injection may be used for certain water-bearing cracks or where a more flexible treatment is needed.

Crack injection is only one part of the repair. If the surrounding concrete has deteriorated or the reinforcement is corroding, that work also needs to be addressed rather than simply filling the visible crack.

Bridge Expansion: Joint Repairs and Replacement

Expansion joints allow a bridge to move in response to traffic, temperature changes and movement between sections. When a joint deteriorates, water and debris can pass into the structure below. Drivers may also experience noise, impact or an uneven transition across the joint.

Entekra repairs and replaces bridge expansion joints as part of planned maintenance and wider bridge-remediation projects.

The work may involve:

• Removing the existing joint system

• Repairing damaged concrete around the joint

• Reinstating the joint nosings

• Installing the replacement joint

• Sealing around the completed system

During a maintenance program across 17 bridges in the Somerset Region, Entekra replaced expansion joints on 15 bridges. The project also included pressure cleaning, concrete repairs and penetrating treatments.

Bridge Strengthening

A bridge may require strengthening when loads change, deterioration affects an existing component or an asset is being upgraded.

Depending on the project design, strengthening may include Carbon Fibre Reinforced Polymer (CFRP), Fibre Reinforced Polymer (FRP), crack injection or other specified repair and reinforcement systems.

CFRP plates and FRP fabrics can add capacity without introducing significant weight or bulky structural sections. They may be used on beams, decks and other bridge components where additional flexural or shear capacity is required.

Any damaged concrete beneath the strengthening system must first be repaired and properly prepared. The performance of a bonded system relies on the condition of the surface to which it is attached.

Concrete Protection and Corrosion Control

Completing a concrete repair without considering the surrounding exposure conditions can leave the bridge vulnerable to further deterioration.

Once repairs are complete, a protective treatment may be used to reduce the movement of moisture and contaminants through the concrete. Depending on the requirements of the bridge, this may include penetrating treatments, sealers, anti-carbonation coatings or other protective systems.

Protection work can be particularly important where concrete is regularly exposed to rain, spray, salts or contaminants carried by traffic.

Planned Bridge Maintenance

Not every bridge remediation project begins with major structural damage. Planned maintenance can address smaller defects before they develop into larger and more disruptive repairs.

Maintenance work may include:

• Cleaning concrete surfaces

• Inspecting and repairing isolated defects

• Sealing cracks

• Replacing damaged joints

• Reapplying protective treatments

• Treating early reinforcement corrosion

• Repairing small areas of spalling

• Monitoring previous repair areas

A planned approach also allows work to be grouped and staged across several bridge assets.

Bridge Remediation Experience

Entekra has completed concrete repair and maintenance work on bridges across Queensland.

At Bon Accord Bridge in Gayndah, the work included concrete spalling repairs and colloidal silica treatment to the concrete columns and supports.

Entekra has also completed a maintenance program covering 17 bridges in the Somerset Region. The bridges were pressure cleaned and treated, concrete repairs were carried out on two structures, and expansion joints were replaced on 15.

This experience brings together the different parts of bridge remediation: preparing the structure, repairing damaged concrete, protecting the remaining concrete and completing joint work within a managed infrastructure project.

Managing Access and Disruption

Bridge work often needs to be completed while roads, surrounding infrastructure or public areas remain in use. Access can also be difficult, particularly beneath bridge decks or around waterways and embankments.

Before work starts, the repair sequence must take account of site access, traffic requirements, safety controls and the time available for each stage.

Where practical, remediation can be divided into sections so that individual areas are completed and returned to service progressively.

Talk to Entekra About Bridge Remediation

Entekra provides bridge remediation, concrete repairs, expansion-joint replacement, crack injection, strengthening and protective treatments for existing bridge assets.



Contact Entekra to discuss upcoming bridge repairs, maintenance programs or remediation requirements.

BENEFITS OF BRIDGE REMEDIATION