Title:
Sectional Shear Strength Analysis and Strengthening Design of Garage Post-Tensioned Beams and Girders
Author(s):
Kurt Tyler
Publication:
Web Session
Volume:
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/25/2020
Abstract:
The top level of a parking garage was repurposed as a restaurant with a plaza terrace that included large planters for trees. The increase in live and dead loads required the underlying continuous post-tensioned concrete girders and conventionally reinforced beams to be evaluated for strengthening. Based on the new demands and capacity of the existing structure, only shear strengthening was required. This article evaluates the influence of various factors on the shear strength, including determining the in-situ concrete compressive strength, the density of the lightweight concrete, and actual layout of the transverse reinforcement, as well as the secondary effects of post-tensioning in a continuous beam, strand positioning, and moment-shear demand. Using various provisions from ACI 318, ACI 440, and ACI 562, the net effect of the analysis was a significant reduction in the effort and quantity of proposed repairs.