Title:
Simplified Computations for Effective Moment of Inertia Ie and Minimum Thickness to Avoid Deflection Computations
Author(s):
Jacob S. Grossman
Publication:
Journal Proceedings
Volume:
78
Issue:
6
Appears on pages(s):
423-439
Keywords:
beams (supports); building codes; concrete slabs; deflection; flexural strength; lightweight concretes; moments of inertia; rectangular beams;reinforced concrete; serviceability; stiffness; structural analysis; structural design;T-beams.
DOI:
10.14359/10526
Date:
11/1/1981
Abstract:
An approximate simplified procedure is described for estimating the effective moment of inertia I, for beams, T-beams, or one-way slabs constructed of normal weight aggregate concrete or lightweight concrete, and reinforced with 40-80 ksi reinforcing bars. The results are compatible with Ie values obtained from Eq. (9-7) of ACI 318-77. The simplified equations do not require computations for moment of inertia of the cracked section Icr, nor the reinforcing requirements initially. Also described is a simplified procedure for establishing minimum member depth so that deflection computations to ascertain serviceability may be avoided when designing the majority of one-way members.