Title:
Vertical Punching Capacity of Reinforced Concrete Flat Plates without Shear Reinforcement
Author(s):
Srinivas Mogili, Hsiang-Yun Lin, and Shyh-Jiann Hwang
Publication:
Structural Journal
Volume:
121
Issue:
1
Appears on pages(s):
171-184
Keywords:
ACI 318; analytical model; design codes; Eurocode 2; flat plates; punching; reinforced concrete; shear strength; softened strut-and-tie (SST)
DOI:
10.14359/51739193
Date:
1/1/2024
Abstract:
Reinforced concrete flat-plate systems are widely adopted in buildings owing to ease of construction and facilitating larger clear
story heights. Flat plates are routinely designed for two-way
shear to preclude brittle punching failures. Accurate assessment
of concrete contribution to shear strength is particularly important
for flat plates in carrying out a reliable and economical design. To
address this, an efficient analytical method based on the softened
strut-and-tie model to estimate punching capacity of flat plates
without shear reinforcement under gravity loading is presented.
The proposed method can account for the influence of various
key parameters such as concrete strength, plate thickness, column
geometry, longitudinal reinforcement area, and arrangement of
tension reinforcement. The proposed method, when verified against
data from 224 specimens reported in the literature, showed reasonably good accuracy with a mean test-to-estimated capacity ratio of 1.20 and a coefficient of variation (CoV) of 0.19. In comparison, average capacity ratios using ACI 318-19 and Eurocode 2 provisions were 1.60 and 1.27 (CoV of 0.34 and 0.29), respectively.
A comprehensive discussion on the effects of key parameters on
punching behavior of flat plates without shear reinforcement is
presented, and suggestions to improve existing design provisions
are provided.