Title:
BEHAVIOR OF BIAXIALLY LOADED SLAB-COLUMN CONNECTIONS WITH SHEAR STUDS
Author(s):
Eric M. Matzke, Rémy D. Lequesne, Gustavo J. Parra-Montesinos, and Carol K. Shield
Publication:
Structural Journal
Volume:
112
Issue:
3
Appears on pages(s):
335-346
Keywords:
confinement; drift capacity; punching shear; seismic; shear study; two-way slab
DOI:
10.14359/51687408
Date:
5/1/2015
Abstract:
Results are presented from four non-prestressed concrete slab-column connection subassemblies tested under simulated gravity and earthquake-type loading. Each specimen consisted of a large-scale first-story interior slab-column connection reinforced with headed shear studs, loaded to a gravity-shear ratio of 50%, and subjected to biaxial lateral displacements. The slabs, which were nominally identical aside from the shear stud reinforcement design, had a flexural reinforcement ratio in the column strip, based on the effective depth, of 0.7%. Shear stud reinforcement in the test specimens varied in terms of amount and spacing, both between and within stud peripheral lines. All four specimens exhibited drift capacities significantly lower than shown by previous studies. Although the lateral strength of the specimens was governed by the flexural capacity of the slab, severe concrete degradation ultimately limited the drift capacity of the connections. Signs of punching-related damage were first observed during the cycle to 1.85% drift in each loading direction. Test results suggest that the minimum amount of shear reinforcement required in Section 21.13.6 of ACI 318-11 when neither a drift nor a combined shear-stress check is performed (vs = 3.5vfc', psi
[0.29vfc', MPa]) is adequate for connections subjected to a gravity shear ratio of up to 50% and resultant drifts from biaxial displacements up to 2.0% if studs are spaced at less than 2d within the first two peripheral lines. For larger drift demands, a maximum stud spacing within the first three peripheral lines of 1.5d is recommended.
Related References:
ACI Committee 318, 2011, “Building Code Requirements for Structural Concrete (ACI 318-11) and Commentary,” American Concrete Institute, Farmington Hills, MI, 503 pp.
ASTM A615/A615M-09, 2009, “Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement,” ASTM International, West Conshohocken, PA, 6 pp.
Broms, C. E., 2007, “Flat Plates in Seismic Areas: Comparison of Shear Reinforcement Systems,” ACI Structural Journal, V. 104, No. 6, Nov.-Dec., pp. 712-721.
Cheng, M.-Y., 2009, “Punching Shear Strength and Deformation Capacity of Fiber Reinforced Concrete Slab-Column Connections under Earthquake-Type Loading,” PhD dissertation, University of Michigan, Ann Arbor, MI, 334 pp.
Cheng, M.-Y.; Parra-Montesinos, G. J.; and Shield, C. K., 2010, “Shear Strength and Drift Capacity of Fiber-Reinforced Concrete Slab-Column Connections Subjected to Biaxial Displacements,” Journal of Structural Engineering, ASCE, V. 136, No. 9, pp. 1078-1088. doi: 10.1061/(ASCE)ST.1943-541X.0000213
Comité Européen de Normalisation, 2004, “Eurocode 2: Design of Concrete Structures — Part 1-1: General Rules and Rules for Buildings (EN 1992-1-1:2004),” Brussels, Belgium, 225 pp.
Dilger, W. H., and Brown, S. J., 1994, “Earthquake Resistance of Slab-Column Connections,” Proceedings of Canadian Society of Civil Engineering Conference, Winnipeg, MB, Canada, pp. 388-397.
Dilger, W. H., and Cao, H., 1991, “Behavior of Slab-Column Connections Under Reversed Cyclic Loading,” Proceedings of the 2nd International Conference of High-Rise Buildings, China.
Durrani, A. J.; Du, Y.; and Luo, Y. H., 1995, “Seismic Resistance of Nonductile Slab-Column Connections in Existing Flat-Slab Buildings,” ACI Structural Journal, V. 92, No. 4, July-Aug., pp. 476-487.
Farhey, D. N.; Adin, M. A.; and Yankelevsky, D. Z., 1993, “RC Flat Slab-Column Subassemblages Under Lateral Loading,” Journal of the Structural Division, ASCE, V. 119, No. 6, pp. 1903-1916. doi: 10.1061/(ASCE)0733-9445(1993)119:6(1903)
Hawkins, N. M.; Mitchell, D.; and Sheu, M. S., 1974, “Cyclic Behavior of Six Reinforced Concrete Slab-Column Specimens Transferring Moment and Shear,” Progress Report, University of Washington, Seattle, WA.
Hueste, M. B., and Wight, J. K., 1999, “Nonlinear Punching Shear Failure Model for Interior Slab-Column Connections,” Journal of Structural Engineering, ASCE, V. 125, No. 9, pp. 997-1008. doi: 10.1061/(ASCE)0733-9445(1999)125:9(997)
Islam, S., and Park, R., 1976, “Tests on Slab-Column Connections with Shear and Unbalanced Flexure,” Journal of the Structural Division, ASCE, V. 102, No. 3, pp. 549-568.
Kang, S.-M.; Park, H.-G.; and Kim, Y.-N., 2013, “Lattice-Reinforced Slab-Column Connections under Cyclic Lateral Loading,” ACI Structural Journal, V. 110, No. 6, Nov.-Dec., pp. 929-940.
Matzke, E.; Lequesne, R. D.; Shield, C. K.; and Parra-Montesinos, G. J., 2013, Drift Capacity of Slab-Column Connections Reinforced with Headed Shear Studs and Subjected to Combined Gravity Load and Biaxial Displacements, 256 pp.
Megally, S. H., 1998, “Punching Shear Resistance of Concrete Slabs to Gravity and Earthquake Forces,” PhD dissertation, Department of Civil Engineering, University of Calgary, AB, Canada, 468 pp.
Megally, S. H., and Ghali, A., 2000, “Seismic Behavior of Edge Column-Slab Connections with Stud Shear Reinforcement,” ACI Structural Journal, V. 97, No. 1, Jan.-Feb., pp. 53-60.
Morrison, D. G., and Sozen, M. A., 1981, “Response of Reinforced Concrete Plate-Column Connections to Dynamic and Static Horizontal Loads,” PFR-78-16318, University of Illinois at Urbana-Champaign, Urbana, IL, 272 pp.
Pan, A., and Moehle, J. P., 1989, “Lateral Displacement Ductility of Reinforced Concrete Flat Plates,” ACI Structural Journal, V. 86, No. 3, May-June, pp. 250-258.
Rha, C.; Kang, T. H.-K.; Sin, M.; and Yoon, J. B., 2014, “Gravity and Lateral Load-Carrying Capacities of Reinforced Concrete Flat Plate Systems,” ACI Structural Journal, V. 111, No. 4, July-Aug., pp. 753-764.
Robertson, I. N., 1990, “Seismic Response of Connections in Indeterminate Flat-Slab Subassemblies,” PhD thesis, Department of Civil Engineering, Rice University, Houston, TX, 284 pp.
Robertson, I. N., and Johnson, G., 2006, “Cyclic Lateral Loading of Nonductile Slab-Column Connections,” ACI Structural Journal, V. 103, No. 3, May-June, pp. 356-364.
Robertson, I. N.; Tadashi, K.; Lee, J.; and Enomoto, B., 2002, “Cyclic Testing of Slab-Column Connections with Shear Reinforcement,” ACI Structural Journal, V. 99, No. 5, Sept.-Oct., pp. 605-613.
Symonds, D. W.; Mitchell, D.; and Hawkins, N. M., 1976, “Slab-Column Connections Subjected to High Intensity Shears and Transferring Reversed Moments,” Report No. SM 76-2, Division of Structures and Mechanics, Department of Civil Engineering, University of Washington, Seattle, WA.
Tian, Y.; Jirsa, J. O.; Bayrak, O., Widianto; and Argudo, J. F., 2008, “Behavior of Slab-Column Connections of Existing Flat-Plate Structures,” ACI Structural Journal, V. 105, No. 5, Sept.-Oct. pp. 561-569.
Wey, E. H., and Durrani, A. J., 1992, “Seismic Response of Interior Slab-Column Connections with Shear Capitals,” ACI Structural Journal, V. 89, No. 6, Nov.-Dec., pp. 682-691.
Zee, H. L., and Moehle, J. P., 1984, “Behavior of Interior and Exterior Flat Plate Connections Subjected to Inelastic Load Reversals,” Report No. UCB/EERC-84/07, Earthquake Engineering Research Center, University of California, Berkley, Berkley, CA, 130 pp.