Building Durable Structures Considerations for concrete, waterproofing, and longevity by Alireza Biparva, B.Sc., M.A.Sc. Photos courtesy Kryton International THE U.S. CONSTRUCTION INDUSTRY IS SHIFTING PERSPECTIVES FROM TRADITIONAL BUILDING TOWARD A GREEN, MORE SUSTAINABLE DESIGN SENSIBILITY. THIS APPROACH INCLUDES BUILDING CONCRETE STRUCTURES THAT WILL LAST AN APPROPRIATE LIFESPAN WITH MINIMAL MAINTENANCE AND REPAIRS—AND THIS NECESSITATES CAREFUL ATTENTION PAID TO THE WATERPROOFING STRATEGIES CHOSEN. If built sustainably, maintenance and repair for concrete buildings should not be as cumbersome an issue as noted in the past. While general upkeep will always contribute to a project’s lifecycle costs, it will not be nearly to the degree experienced for projects where concrete is continually needed to be worked on, and where deterioration reaches the point where full reconstruction—a daunting, and occasionally impossible task—is considered. While routine maintenance is expected on any structure, its difference from major repairs is significant. Referring to De Sitter’s Law of Fives, a major repair can be expected to cost roughly five times what routine maintenance would have cost. 1 An all-out replacement will then be five times what a major repair would have cost. Avoiding major repairs and replacement issues are of the utmost importance for ensuring the financial viability of a 52 the construction specifier | november 2015 CS_November2015.indd 52 2015-10-15 9:25 AM