Title: Modification of Approximate Method of ACI 318 Prestressed Concrete Shear Provision

Author(s): D. Lee, H. Shin, M. Yerzhanov, H. Ju, and T. H.-K. Kang

Publication: Structural Journal

Volume: 120

Issue: 3

Appears on pages(s): 131-144

Keywords: approximate method; limit condition; modification; prestressed concrete; shear design; shear strength

DOI: 10.14359/51738463

Date: 5/1/2023

Abstract:
In response to the longstanding concerns regarding the impracticality of ACI 318 prestressed concrete (PC) one-way shear provisions, rational improvements to the approximate method were discussed. This study addresses new limit conditions reflecting prestress effects and corresponding updates on upper-limit shear strength (Vc). Also, a consistent and straightforward definition of effective depth (dv) and coefficient accounting for longitudinal reinforcement effect (K) were newly introduced. The proposed approximate method was verified through use of an extensive PC shear database to have analytical accuracy and conservatism statistically comparable to the ACI 318-19 approximate provision. In addition, applicability was confirmed through analysis of four design examples. The proposed modifications are an advisable alternative to the current approximate method. They provide for simple, economical, and safe PC member design while resolving underlying issues in the current approximate method.