Title:
Strengthening of Two-Way Slabs Subjected to Moment and Cyclic Loading
Author(s):
U. Ebead and H. Marzouk
Publication:
Structural Journal
Volume:
99
Issue:
4
Appears on pages(s):
435-444
Keywords:
concrete; reinforcement; repair; shear; strength
DOI:
10.14359/12112
Date:
7/1/2002
Abstract:
A two-way slab is an optimum gravity load-resisting system. Its resistance to lateral loads, however, is questionable. Upgrading or strengthening a two-way slab to column connection is a reliable means of improving the lateral resistance of the two-way slab system. This paper provides further details on the application of a strengthening technique using steel plates and steel bolts of two-way slabs subjected to different load types. The tested slabs were of two different reinforcement ratios of 0.5 and 1.0% and were subjected to central load, moment, and cyclic landings. Results of 11 specimens were evaluated. The specimens were square in shape with a side length of 1900 mm. A column of 250 mm square in cross section was located at the slab center and extended to a distance of 850 mm above and below the slab surfaces. The strengthening steel plates were extended to twice the slab depth around the column. The ultimate load was increased by an average of a minimum of 45 and 122% for specimens subjected to central load and central load plus moment, respectively. For specimens subjected to cyclic loading, the strengthening contributed to an increase of the horizontal cyclic drift by 76% compared with the reference (unstrengthened) specimens.