Skanska USA, the contractor hired to construct the $400 million Pensacola Bay Bridge in Florida, could earn a $15 million bonus for completing the work early. Likewise, when it contracted out the development of a collapsed section of Interstate 85, the Georgia Department of Transportation offered a $3.1 million early completion bonus to the contractor.
Fast-tracking bridge projects can be very lucrative for contractors — if the work is done right. There are numerous steps along the way where work can be accelerated, and one of these involves waterproofing the bridge deck. Consider the following five tips.
1. Choose the Right Removal Method
If you’re refurbishing a bridge, removal of the original coating and waterproofing can be a time-consuming process. Talk with your waterproofing manufacturer to find out about the various removal methods, such as water blasting, that could minimize manual efforts. The removal method will depend on many factors, including the chemical composition of the original coatings and the type of waterproofing membrane being applied.
2. Involve the Manufacturer in Pre-Site Inspections
Including the manufacturer is important for new construction as well as rehabilitation projects. For bridges that are being refurbished, the condition of the existing paving and waterproofing membrane will influence the refurbishment plan. For example, the amount of surface prep needed can vary, depending on the type and condition of materials used previously. In some cases, a single pass of a blast machine won’t be enough to clean the surface. If this prep isn’t done right, it can impact the bond between the bridge waterproofing and the substrate.
It can be hard to know what situation you’re getting into without seeing these conditions firsthand. The manufacturer should have insight to the site specifics with their products, which is why pre-site visits are essential.
3. Prevent Weather Delays
As the weather gets colder, ice crystals or condensation may accumulate on the bridge deck. This can result in work being halted when it’s too cold out. Nobody wants to have a crew waiting around to apply waterproofing until the weather changes. To extend your construction season and avoid work delays, consider choosing a liquid waterproofing system that can be applied in moist, freezing temperatures, or be sure to build in extra time since you may need to wait for temps to rise. Be aware: Many waterproofing membrane manufacturers claim to have liquid membranes that are cold applied. However, some of these products must be heated up when used in the wintertime. This is to ensure they don’t become too thick. To avoid this additional step, and the extra cost of bringing generators to the site, be sure to confirm before you start that the product will work within the confines of your project and its temperatures.
4. Use On-the-Spot QA Tools
Having the right quality assurance (QA) methodologies can give contractors the peace of mind that they’ve performed a high-quality application. It’s easy to validate the waterproofing membrane’s performance through adhesion testing that ensures the entire system is going to be fully bonded to the substrate. This way, as you apply subsequent coats of the waterproofing product(s), you know you have a chemical bond between the waterproofing layers and the substrate below. Wet film thickness (WFT) testing can also be performed immediately to verify that the waterproofing was applied properly. This allows applicators to instantly identify and repair any areas in need.
5. Consider a Phased Approach
Having the flexibility to perform certain work during overnight possession, such as spraying on the waterproofing membranes, can accelerate project completion and minimize frustration for commuters who rely on the bridge. This is a factor to consider when selecting your waterproofing membrane and planning its installation. Some tasks will be better done at different times.
About the Author:
Lynn Connors is global marketing manager of liquid-applied waterproofing at GCP Applied Technologies. She has more than 15 years’ experience growing emerging markets by bringing innovative solutions to market. Connors has held senior management positions at iRobot Corporation and Velcro USA Inc., and she has an Executive MBA from the University of New Hampshire. For more information, contact: GCP, https://gcpat.com