| Author(s) | Ahmed B. Shuraim |
| Affiliation | Department of Civil Engineering, College of Engineering, King Saud University, P. O. Box 800, Riyadh, 11421, Saudi Arabia |
| Title | Applicability of Code Design Methods to RC Slabs on Secondary Beams. Part I: Mathematical Modeling |
| Source | Journal of King Saud University. Engineering Sciences. Volume 15, No 2. (2003/1423) |
| Abstract | Abstract. The behavior and the appropriate method of analysis for two-way slab systems supported by a grid of main and secondary beams are not fully understood. The overall objective of this two-part study is to investigate the applicability of the ACI code methods for evaluation of design moments for such slab systems. This part analyzes five beam-slab-systems of different configurations through the code and finite element procedures. One slab system was without secondary beams while the remaining four have secondary beams with bearing beam- to-slab depth ratios from 2.6 to 5. The secondary beams were found to reduce the floor weight by upto 30 % when the five slab systems were of equal stiffness. However, achieving slab-systems of equal stiffness is not straightforward and cannot be evaluated from section properties only. It was found that derivation of equal stiffness of the slab systems based on section properties alone resulted in an error of 38 % in computed deflection. In beam-slab systems, the rib projection of the beam poses a modeling challenge. Two options were considered: physical offset with rigid link option or equivalent beam option in which the size of the beam was increased to compensate for the rib offset. In this part the study, the advantages and drawbacks of both modeling approaches are discussed. Keywords: Reinforced concrete slabs; Design methods; Secondary beams; Beam-slab systems; Mathematical modeling; Codes of practice. |
