As infrastructure ages, maintaining bridge decks becomes increasingly important to ensure safety and longevity. One key aspect of bridge deck maintenance is having an effective waterproofing system to prevent corrosion and deterioration. This guide covers the basics of bridge deck waterproofing, to help infrastructure owners and managers make informed decisions.
Why Waterproof Bridge Decks?
Water is one of the main causes of bridge deck deterioration. Without an adequate protective barrier, water can seep into the concrete and reach the reinforcing steel underneath. This causes:
- Corrosion of the steel – As it rusts, the steel expands putting outward pressure on the concrete. This leads to further cracking and spalling.
- Freeze-thaw damage – Water that has penetrated the deck can freeze and expand in winter. This stresses the concrete and causes cracks and splits.
- Premature wear – Constant moisture access weakens the concrete and causes surfaces to erode faster.
An effective waterproofing system prevents these expensive problems and extends the service life of bridge decks.
Types of Bridge Deck Waterproofing Systems
There are two main types of waterproofing systems used for bridge decks today:
Membranes
These systems involve rolling out sheet materials that act as a protective barrier:
- Hot-applied rubberised asphalt membranes
- Preformed composite membranes
- Liquid-applied membranes
Membranes create a continuous waterproof barrier across the deck surface.
Concrete Sealers
These penetrate into the concrete surface and make it more impermeable:
- Silane sealers
- Acrylic sealers
- Epoxy sealers
Concrete sealers work by filling pores to reduce permeability.
Hybrid Waterproofing Solutions
Often dual waterproofing systems are used for maximum protection of critical infrastructure. This may involve a membrane layer for continuous barrier protection, paired with a concrete sealer underneath for deep penetration waterproofing.
The two systems working together provide both a defensive surface barrier, along internal concrete strengthening. Consult with our experts on optimal pairings for hybrid waterproofing.
Key Properties to Look For
When evaluating waterproofing systems, there are a few key properties to consider:
- Crack bridging ability – The system must be flexible to stretch and move over cracks without compromising the barrier. Look for stretch capacity over 10%.
- Strong adhesion – For membranes, the laps must adhere strongly to prevent moisture access. For sealers adequate surface penetration and bonding are key.
- Durability – Exposure to sun, winter temperatures, and foot and vehicle traffic means the systems experience harsh conditions. Only proven durable products should be selected. Look for outdoor exposure testing.
- Ease of inspection – Once installed, the system should allow for non-destructive inspection to check for breaches or failures.
Some other factors like thickness, solar reflectance, and permeability ratings will be provided for each product. Review these parameters when selecting systems to meet project requirements.
Installation Best Practices
While the products themselves are engineered to be effective, attention must also be given to proper installation:
- Surface preparation – Concrete surfaces must be cleaned and profiled to enable bonding and penetration of waterproofing materials.
- Detail work – Special care must be taken at joints, corners, and penetrations to provide continuous protection. Pre-formed detailing accessories are used.
- Weather conditions – Ideal conditions are dry weather between 40-100°F. Follow manufacturer specifications for allowable installation temperature and moisture ranges.
- Training and certification – Approved installer training programs are offered for more complex products to ensure correct handling and application. Verify the installer is properly qualified.
With manufacturer-approved products and trained applicators, excellent long-term bridge deck protection can be achieved.
Conclusion
With ageing infrastructure, effective bridge deck waterproofing is increasingly important for longevity and reducing maintenance costs.
As bridge waterproofing contractors, Vision Specialist Contracting offers installation services for all major waterproofing systems. Our certified technicians are experts in surface preparation, detail work, and achieving a continuous protective barrier on your bridge. We also advise infrastructure owners and managers on selecting appropriate products to meet durability, inspection, and other project requirements unique to each bridge.
Contact Vision today to discuss an optimised bridge deck waterproofing solution tailored for your specific bridges. Investing in high-performance waterproofing now will pay dividends through extended lifespan and reduced future maintenance. We offer complimentary consultations and estimates to review your bridge portfolio and maintenance goals.
Frequently Asked Questions
How long does bridge deck waterproofing last?
With high-quality materials and proper installation, waterproofing systems generally last 15-25 years before needing renewal.
Does the deck need to be replaced when re-waterproofing?
Usually, the waterproofing membrane or sealer can be applied over the top of existing concrete substrates, without needing full deck reconstruction.
Can waterproofing be added to an existing bridge deck?
Yes absolutely. Many older bridges without original waterproofing can have new systems added. This extends the lifespan at a fraction of the full deck replacement cost.
Who does the installation work?
Speciality waterproofing contractors with trained, certified technicians will have the expertise to install these systems properly.
