Concrete structures can have a long shelf-life if proper construction techniques are used, it is in an ideal environment and is properly maintained. Exposure to moisture, freeze-thaw cycles, and deicing chemicals can adversely affect concrete structures. When looking at your existing infrastructure or other properties, ask yourself:
Do We Know the Construction Technique Used?
In the early 1900’s, the construction industry and engineers developed different concrete construction techniques to gain an advantage over competitors. The industry was still learning the limits of concrete, specifically elevated slab construction, and aimed for the thinnest floor section and greatest spacing of columns. As such, we’ve learned some techniques weren’t best suited for the intended use. It’s important to understand the construction techniques of these older concrete structures before attempting any modifications to the structure.
What’s the Exposure?
Concrete structures will rarely have long-term issues if it’s protected from water, in relatively constant and ideal temperature/humidity, and has little to no joints. This type of structure is almost impossible to build because of the common issue of needed joints, which can fail over time if not maintained and protected. Parking ramps can experience many issues regarding joints and often require inspections by a professional engineer to assess these conditions. For other structures, an understanding of the building envelope is needed to prepare proper maintenance plans.
No Existing Drawings? Now What?
Original construction documents are an engineer’s best friend when doing existing structures assessments. While a full set of documents is rare for buildings built before the 1960’s, any documentation is useful in identifying opportunities for modification and assessing load limitations. If no documents are available, there are different testing techniques to help assess the limits. Using data obtained from these techniques, we can better understand structures and advise owners to either proceed or make adjustments to plans.
The Structures Evaluation and Building Sciences groups at Braun Intertec have technicians, engineers and architects that complete testing, observations and assessments for most concrete structures. We’ve worked with many owners and property management companies to help determine the causes of deterioration and develop repair options or proper maintenance plans. Contact Jason Hanlon at 651.487.7074 for more information.