The 60-year Evolution of Durable, Post-Tensioned Concrete Parking Structures
Presented By: Tim Christle
Affiliation:
Description: From 1965, when Carl founded Carl Walker & Associates, Inc., to today, there has been a noteworthy 60-year evolution of design and construction improvements associated with post-tensioned (PT), cast-in-place concrete parking structures. This presentation examines advancements in post-tensioning reinforcement systems, design strategies, construction tactics, and the lessons learned that helped inform these advancements. Best practices for durable PT parking structures in 2025 will also be highlighted.
H. Carl Walker, P.E., the Pioneer and Mentor to Many
Presented By: Paul Tourney
Affiliation: Tourney Consulting Group, LLC
Description: Harry Carl Walker was a true pioneer in the engineering fields of structures, construction, and building materials. This presentation will highlight Mr. Walkers impacts to the parking industry and to individuals from this author’s experiences. H Carl Walker was a friend, early adopter, visionary, leader, mentor, and young engineer sponsor.
EV Weight: Is it an Issue for Design Loads?
Presented By: Rashid Ahmed
Affiliation: Walker Consultants
Description: Honoring Carl Walker, a well-known in the parking industry. Carl established Walker Parking Consultants in 1965, which is now one of the leading parking consultants in the country. As the popularity of electric vehicles has grown, there is continued concern that Electric Vehicles are too heavy predominantly because of the batteries used to power them. Does the code prescribed design live loads need to be re-evaluated for parking structures based on electric vehicle weight, relying on a certain percentile weight. The presentation will also include vehicle size and EV sales trends. Design Vehicle and 85th Percentile, Impact of EVs on curb weight of passenger vehicles, and Design Loads.
Dapped and Notched Ends in Thin-Stemmed Prestressed Concrete Beams
Presented By: Gregory Lucier
Affiliation: NC State University
Description: Thin-stemmed prestressed double-tee beams are common in precast concrete construction, including parking garages and data centers. The ends of these members are often dapped or notched to accommodate offset bearing heights, or to reduce the overall floor-to-floor dimension, necessitating careful proportioning of internal reinforcement to accommodate the geometric discontinuity introduced. This presentation summarizes the ongoing work at NC State University to study the behavior of dapped and notched-end beams, with a focus on the differences in response between dapped ends and notched end members.