Title:
Assessment of Deflection Prediction Models for Cracked Prestressed Concrete Beams
Author(s):
Wassim Nasreddine, Adi Obeidah, Peter H. Bischoff, and Hani Nassif
Publication:
Structural Journal
Volume:
120
Issue:
6
Appears on pages(s):
167-179
Keywords:
deflection; effective moment of inertia; partially prestressed; prestressed concrete
DOI:
10.14359/51739094
Date:
11/1/2023
Abstract:
Variability of deflection prediction models is assessed for cracked
prestressed concrete flexural members with bonded steel tendons.
Current models for computing deflection are based on an effective
moment of inertia (with or without an offset moment for the cracked
section response) or a bilinear moment-deflection response using
the moment of inertia of the uncracked section before cracking and
moment of inertia of the cracked section after cracking. The accuracy
of the approaches provided in ACI 318-19, the PCI Design
Handbook, and elsewhere are examined for computing immediate
deflection using a large database of 180 fully prestressed as
well as partially prestressed beams. Parameters considered in the
analysis include the effect of tension-stiffening, reinforcement ratio,
prestressing type (fully or partially prestressed), cracking moment,
concrete elastic modulus, modulus of rupture, and the use of transformed or gross section properties. Results highlight the need for a rational model that can be universally applied to reinforced as well as prestressed concrete flexural members.