過去許多研究證實提供拉力側撓曲鋼筋可以有效增加版柱接合部貫穿剪力強度，但鮮少有文獻對配置於其他深度的撓曲鋼筋進行探討。以單向構件如鋼筋混凝土梁而言，增加壓力筋強度影響有限，但能增加構件變形能力，過去文獻對於雙向版壓力側撓曲鋼筋的相關討論非常有限。

本研究透過搜集過去已完成之實驗數據(資料庫共包含66組試體)，以及五座近實尺寸版柱接合部試體，初步了解撓曲鋼筋配置於版內不同深度對無梁版貫穿剪力強度與變形能力之影響。五座試體主要實驗變數為(1)提供額外撓曲鋼筋於版內不同深度(與拉力側撓曲鋼筋同深度、版厚中央、版壓力側)、(2)額外撓曲鋼筋配置範圍、以及(3)額外撓曲鋼筋截斷與否。

實驗結果顯示，除對照組試體外，其餘試體破壞模式均為貫穿剪力破壞；額外撓曲鋼筋配置深度從拉力側同深度變更至壓力側時，接合部強度提升22%，變形能力提升64%，且試體拉力側環狀裂縫分布範圍增加約1.5d；不論配置於版深度何處，增加額外撓曲鋼筋配置範圍均能增加接合部強度；額外撓曲鋼筋有截斷之試體，於貫穿剪力破壞前額外撓曲鋼筋均明顯發生握裹失效。透過資料庫數據分析，本研究進一步發現，額外增加拉力側撓曲鋼筋於特定區域能提升接合部剪應力強度，但提升效果不明顯；ACI 318-19 (ACI Committee 318, 2019)所建議之最小拉力撓曲鋼筋量限制不保守；增加拉力側撓曲鋼筋量時，透過適當配置壓力側撓曲鋼筋維持版的標稱彎矩強度對應曲率，能進而維持接合部變形能力。

This research aims to explore the effect of flexural reinforcement placed at different depths within the slab on the punching shear capacity of slab-column joints, using a database comprising 66 sets of completed experimental data and five near full-scale specimens to find preliminary conclusions. The test parameters for the five specimens include (1) providing additional flexural reinforcement at different depths within the slab (same depth as tension reinforcement, central depth of the slab, and compression-side of the slab), (2) the range of additional flexural reinforcement placement, and (3) whether the additional flexural reinforcement is cut off or not.

The experimental results indicated that all specimens’ failure mode are controlled by punching shear. When the depth of additional flexural reinforcement was changed from the tension side to the compression side, the joint strength increased by 22%, and the deformation capacity increased by 64%. Regardless of the placement depth within the slab, increasing the range of additional flexural reinforcement can enhanced the joint strength. Specimens with cut off additional flexural reinforcement occurred significant anchorage failure before punching failure. Through the database, this study found that concentrating the tension reinforcement didn’t significantly enhance the joint strength. The minimum requirement for tension reinforcement recommended by ACI 318-19 (ACI Committee 318, 2019) was found to be non-conservative. By properly placing compression reinforcement, the nominal curvature of the slab could be increase, and enhanced the deformation capacity of the joint afterward.

ACI Committee 318, 2019, “Building Code Requirements for Structural Concrete and Commentary(ACI318-19),” American Concrete Institute, Farmington Hills, Michigan, 623 pp.

Adetifa, B., and Polak, M. A., 2005, “Retrofit of Slab Column Interior Connections Using Shear Bolts,” ACI Structural Journal, 102(2), pp. 268-274.

Alexander, S. D. B., and Simmonds, S. H., 1992, “Tests of Column-Flat Plate Connections,” ACI Structural Journal, 89(5), pp. 495-502.

Bazant, Z. P., and Cao, Z., 1987, “Size Effect in Punching Shear Failure of Slabs,” ACI Structural Journal, 84(1), pp. 44-53.

Birkle, G., and Dilger, W. H., 2008, “Influence of Slab Thickness on Punching Shear Strength,” ACI Structural Journal, 105(2), pp. 180-188.

Cantone, R., Fernández Ruiz, M., Bujnak, J., and Muttoni, A., 2019, “Enhancing Punching Strength and Deformation Capacity of Flat Slabs,” ACI Structural Journal, 116(5), pp. 261-274.

Dam, T., Wight, J., and Parra-Montesinos, G., 2017, “Behavior of Monotonically Loaded Slab-Column Connections Reinforced with Shear Studs,” ACI Structural Journal, 114(1), pp. 221-232.
 
Donmez, A., and Bazant, Z., 2017, “Size Effect on Punching Strength of Reinforced Concrete Slabs without and with Shear Reinforcement,” ACI Structural Journal, 114(4), pp. 875-886.

Ebead, U., and Marzouk, H., 2002, “Strengthening of Two-Way Slabs Using Steel Plates,” ACI Structural Journal, 99(1), pp. 23-31.

Elstner, R. C., and Hognestad, E., 1956, “Shearing Strength of Reinforced Concrete Slabs,” ACI Journal Proceedings, 53(7), pp. 29-58.

Guandalini, S., Burdet, O., and Muttoni, A., 2009, “Punching Tests of Slabs with Low Reinforcement Ratios,” ACI Structural Journal, 106(1), pp. 87-95.

Hawkins, N. M., and Ospina, C. E., 2017, “Effect of slab flexural reinforcement and depth on punching strength,” ACI Symposium Publication, 315, pp. 117-140.

Lee, J. H., Yoon, Y. S., Cook, W., and Mitchell, D., 2009, “Improving Punching Shear Behavior of Glass Fiber-Reinforced Polymer Reinforced Slabs,” ACI Structural Journal, 106(4), pp. 427-434.

Li, K. K. L., 2000, “Influence of Size on Punching Shear Strength of Concrete Slabs,” Master Thesis, Department of Civil Engineering and Applied Mechanics at McGill University. 89 pp.
 
Lips, S., Fernández Ruiz, M., and Muttoni, A., 2012, “Experimental Investigation on Punching Strength and Deformation Capacity of Shear-Reinforced Slabs,” ACI Structural Journal, 109(6), pp. 889-900.

Marzouk, H., and Hussein, A., 1991, “Experimental Investigation on the Behavior of High-Strength Concrete Slabs,” ACI Structural Journal, 88(6), pp. 701-713.

McHarg, P. J., Cook, W. D., Mitchell, D., and Yoon, S. Y., 2000, “Benefits of Concentrated slab Reinforcement and Steel Fibers on Performance of Slab-Column Connections,” ACI Structural Journal, 97(2), pp. 225-234.

Muttoni, A., 2008, “Punching Shear Strength of Reinforced Concrete Slabs without Transverse Reinforcement,” ACI Structural Journal, 105(4), pp. 440-450.

Osman, M., Marzouk, H., and Helmy, S., 2000, “Behavior of High-Strength Lightweight Concrete Slabs under Punching Loads,” ACI Structural Journal, 97(3), pp. 492-498.

Park, H. G., Ahn, K. S., Choi, K.-K., and Chung, L., 2007, “Lattice Shear Reinforcement for Slab-Column Connections,” ACI Structural Journal, 104(3), pp. 294-303.

Rizk, E. R., 2010, “Structural Behaviour of Thick Concrete Plates,” Ph. D. Thesis, Faculty of Engineering and Applied Science Memorial University of Newfoundland. 255 pp.
 
Rodriguez, D. G., and Moehle, J. P., 2021, “Comparative Study of Punching Shear and Concrete Breakout,” ACI Structural Journal, 118(2), pp. 183-192.

Ruiz, M. F., Mirzaei, Y., and Muttoni, A., 2013, “Post-Punching Behavior of Flat Slabs,” ACI Structural Journal, 110(5), pp. 801-812.

Swamy, R. N., and Ali, S. A. R., 1982, “Punching Shear Behavior of Reinforced Slab-Column Connections Made with Steel Fiber Concrete,” ACI Journal Proceedings, 79(5), pp. 392-406.

Teng, S., Cheong, H. K., Kuang, K. L., and Geng, J. Z., 2004, “Punching Shear Strength of Slabs with Openings and Supported on Rectangular Columns,” ACI Structural Journal, 101(5), pp. 678-687.

Vanderbilt, M. D., 1972, “Shear Strength of Continuous Plates,” Journal of the Structural Division, 98(5), pp. 961-973.

Widianto, Bayrak, O., and Jirsa, J., 2009, “Two-Way Shear Strength of Slab-Column Connections: Reexamination of ACI 318 Provisions,” ACI Structural Journal, 106(2), pp. 160-170.

Yamada, T., Nanni, A., and Endo, K., 1992, “Punching Shear Resistance of Flat Slabs: Influence of Reinforcement Type and Ratio,” ACI Structural Journal, 11(67), pp. 555-563.
 
林尚緯，2021年。「粗骨材粒徑大小及撓曲鋼筋量對貫穿剪力強度之影響」，碩士論文，國立臺灣科技大學，136頁。