In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
American Concrete Institute
38800 Country Club Dr.
Farmington Hills, MI
Feedback via Email
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Analysis of Total Deflection of Reinforced Concrete Box Beams
Under Repeated Loading
Author(s): Yew-Chaye Loo and Yen Wen Wong
Publication: Journal Proceedings
Appears on pages(s): 87-94
Keywords: box beams; creep properties; cyclic loads; deflection; live loads; moments of inertia;reinforced concrete; static loads; structural analysis.
Abstract:A simple, computational procedure is presented for the prediction of the total deflection of singly-reinforced concrete box beams under repested loading. The total deflection is obtained by summing the instantaneous live load deflection and the accumulated dead load deflection. The latter may be computed as the product of the intial dead load deflection and intensive creep factor. Following a comparitive study, the most suitable method is chosen from well-known procedures for the computation of the intial dead load deflection. Based on the experimental data on 30 under-reinforced box beams (tested under 100,000 cycles of load), an empirical formula for the intensive creep factor is derived. Parallel to the logarithmic time-creep equation, the formula is considered to be more realistic than an alternative hyperbolic method. For computing the instantaneuos live load deflection of any loading cycle, a new equation for the equivilant moment of interia is proposed. This equation is shown to be superior to existing formulas. All equations recommended for use are simple and explicit. Comparisions with the test results indicate that the proposed computational procedure is generally accurate.
Click here to become an online Journal subscriber