Title: Slenderness Limit for Glass Fiber-Reinforced Polymer Reinforced Concrete Columns: Reliability-Based Approach

Author(s): Koosha Khorramian, Pedram Sadeghian, and Fadi Oudah

Publication: Structural Journal

Volume: 119

Issue: 3

Appears on pages(s): 249-262

Keywords: artificial neural network (ANN); concrete columns; glass fiber-reinforced polymer (GFRP) bars; reliability analysis; slenderness limit

Date: 5/1/2022

Abstract:
The slenderness limits in ACI 318 and ACI 440 are based on a deterministic method of defining slender columns as columns whose second-order capacity is lower than 5% of their firstorder capacity. For the first time, a reliability-based methodology is developed and employed in this research to quantify the safety associated with existing expressions used to calculate the slenderness limit of concrete columns reinforced with glass fiber-reinforced polymer (GFRP) bars, and to propose alternative reliability-based expressions to optimize the design based a predefined target reliability index. The method involves developing a novel artificial neural network (ANN) to conduct second-order analysis, conducting Monte Carlo simulation, and first-order reliability. Analysis results indicate a reliability index ranging from 3.99 to 4.53 for the existing expression in ACI 440. Four alternative design equations for calculating the slenderness limits were proposed and optimized to achieve a target reliability index ranging from 4.0 to 4.5.