Home Secretary's Corner Secretary’s Corner – October 2019 – Joshua White

Secretary’s Corner – October 2019 – Joshua White

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(The following presentation summary is provided thanks to VP Emily McCarthy because, let’s be honest, it’s a bit odd for the secretary to summarize his own presentation in third person!)

Thanks to everyone who braved the weather and made it to our last monthly meeting at Maggiano’s for Josh White’s talk “Condition Assessment of Maritime Piers”. Josh’s expertise surrounds nondestructive evaluation (NDE) technologies, many of which he and his colleagues used to assess the remaining service life of coastal piers that showed signs of wear in precast conventionally-reinforced deck panels. Cracking on the underside of the panels (of varying widths) and visible deflection between panel supports motivated the owner to request load tests of the deck to quantify the deck capacity, as well as service life modeling to assist in repair planning. Conventional approaches for load testing were not feasible – therefore the project team had to develop a unique approach to satisfy project requirements. Service life modeling involved using laboratory analysis of material samples, as well as the use of several NDE methods (including visual observations, ground penetrating radar mapping, chloride testing, impact testing). Josh’s primary findings included:

  1. Some of the precast conventionally reinforced panels did not have a roughened surface to achieve appropriate shear transfer to the 6-in topping slab, per ACI requirements. This ultimately led to a downgrade in live load capacity for select piers.
  2. Aspects of as-built construction (concrete cover, topping thickness, etc.) varied, sometimes resulting in favorable and unfavorable effects on structural capacity.
  3. Cracks observed were primarily flexural and were primarily the result of the designed elements approaching cracked section properties under dead load.
  4. Using service life modeling results, panels from a certain population of precast suppliers showed more expected deterioration than others and helped to guide the owner on prioritizing repairs.
  5. The load test helped to validate the structural modeling and provided the owner with confidence in using the piers.

Our next meeting will include a short presentation from Tristian Ybarra, the recipient of the 2019 Conference Scholarship, as Tristian discusses what he learned from attending this year’s State Conference and some of his internship experiences. Following this, we are happy to host Dr. Joseph Colaco, who will be presenting on his contributions to the design of Pennzoil Place, a unique icon of downtown Houston. Please be sure to join us as we meet again on October 17 and Maggiano’s at Memorial City Mall.