Weathering the Storm: Self-Performing Concrete that Can Withstand the Elements
July 18, 2016
By Brasfield & Gorrie
To self-perform trades well, especially when facing labor shortages across the industry, a contractor must commit to maintaining the highest quality skilled laborers and perfecting the means, methods, and execution of these trades. This focus results in a thorough understanding of every trade and improved control over cost, schedule, and quality on every project.
Self-performing major trades, such as concrete, often benefits projects. Building entire concrete structures or even forming smaller slabs involves extensive planning and finesse to provide exactly the function and aesthetic a given project needs.
Recently, our team had the opportunity to self-perform concrete on a major league ballpark. Ground-up construction of a facility that is exposed to the elements 365 days a year presents unique considerations and challenges beyond those encountered on dried-in projects. Because the concrete must weather the storms (literally) while remaining aesthetically pleasing for patrons, quality considerations included the concrete’s durability and long-term appearance.
To create a superior natural look, our team elected to use a higher grade of plywood than normally used for forming decks. These thick form materials are sanded, treated, and given a veneer. As a result, they provide a smooth, clean finish to the concrete. With most of the decks on the project exposed overhead and underfoot, this technique ensured that the final product met the high standards of both the owner and designer.
Per the design specifications, we also formed warped decks across the ballpark’s wide structural bays, sloping them to strategically placed drains. The design uses a complex drainage system to prevent precipitation from seeping into the concrete structure, which would cause quicker corrosion and cracking. The sloped design for water management dictated the elevations of all the project’s structural concrete components, driving the design specifications and schedule. But by protecting the structure from premature corrosion, it will also extend the stadium’s lifecycle.
Another challenge presented by the ballpark was its 25-foot-high concrete columns, which are exposed for their entire length. Achieving a uniform look from floor to ceiling required smooth steel forms and full-height pours with a leaner concrete mix at the bottom of the columns and standard mix above. The varying mixtures allowed the concrete to flow easily around the rebar at the base of the columns, with the denser concrete above compressing the lighter concrete below and thereby removing imperfections. This process promoted a refined finish.
The project’s extremely high quality standard for exposed concrete called for a careful forming process and extensive upfront quality control to create a crisp, clean finished concrete appearance that will stand the test of time. As with any self-perform project, coordination between our construction team and the design team from the outset ensured an exceptional end product. Extensive planning and collaboration helped us create excellent finishes the first time, preventing rework and keeping the project on budget and on schedule.