Title:
Shear Stiffness of Earthquake-Resistant Concrete Squat Walls Reinforced with Glass Fiber-Reinforced Polymer Bars
Author(s):
Islam Shabana, Ahmed Sabry Farghaly, and Brahim Benmokrane
Publication:
Structural Journal
Volume:
120
Issue:
2
Appears on pages(s):
19-32
Keywords:
fiber-reinforced polymer (FRP); reinforced concrete; seismic; shear stiffness; squat walls; strut and tie; variable-angle truss.
DOI:
10.14359/51738345
Date:
3/1/2023
Abstract:
While evaluating the stiffness properties is crucial for developing the response spectra of structures, none of the North American codes/standards—including ACI 318-19, ASCE/SEI 41-06, ASCE/SEI 43-05, and CSA A23.3-19—offer an explicit analytical approach for estimating the shear stiffness of cracked concrete squat walls. Furthermore, the paucity of experimental research has led to the lack of seismic design provisions for concrete structures reinforced with fiber-reinforced polymer (FRP) bars. Therefore, this study is focused toward investigating the stiffness characteristics of concrete squat walls reinforced with glass FRP (GFRP) bars, aiming at proposing a straightforward method of analysis that can be used to estimate the post-cracking shear stiffness. Four
wall specimens with an aspect ratio (height-to-length ratio) of
1.14 were constructed and tested under simultaneous axial and
reversed-cyclic lateral loads. Test results were analyzed in terms of stiffness degradation trends and decoupled flexural and shear deformations. An analytical model was developed for evaluating the secant shear stiffness at any load level in the post-cracking range. The model was achieved by idealizing the shear-transfer mechanism of the web reinforcement using a variable-angle truss, and that of the web concrete using a direct strut-and-tie system representing the tied arch action developed through the web. A simple analytical expression was formulated for predicting the magnitude of average strain in the web horizontal reinforcement at failure. The validity of the derived model and expressions was examined by reproducing the load-shear displacement response of the tested walls. Further verification was also conducted by reproducing the response of steel-reinforced concrete squat walls available in the literature, considering only their pre-web yielding range.
Related References:
ACI Committee 318, 2019, “Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19),” American Concrete Institute, Farmington Hills, MI, 623 pp.
ACI Committee 440, 2015, “Guide for the Design and Construction of Concrete Reinforced with Fiber-Reinforced Polymer Bars (ACI 440.1R-15),” American Concrete Institute, Farmington Hills, MI, 88 pp.
Arafa, A.; Farghaly, A. S.; and Benmokrane, B., 2018, “Evaluation of Flexural and Shear Stiffness of Concrete Squat Walls Reinforced with Glass Fiber-Reinforced Polymer Bars,” ACI Structural Journal, V. 115, No. 1, Jan., pp. 211-221. doi: 10.14359/51700987
ASCE/SEI 41-05, 2006, “Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities,” American Society of Civil Engineers, Reston, VA, 81 pp.
ASCE/SEI 43-05, 2005, “Seismic Rehabilitation of Buildings,” American Society of Civil Engineers, Reston, VA, 411 pp.
Baek, J. W.; Park, H. G.; Lee, J. H.; and Bang, C. J., 2017, “Cyclic Loading Test for Walls of Aspect Ratio 1.0 and 0.5 with Grade 550 MPa (80 ksi) Shear Reinforcing Bars,” ACI Structural Journal, V. 114, No. 4, July-Aug., pp. 969-982. doi: 10.14359/51689680
CAN/CSA A23.3, 2019, “Design of Concrete Structures,” CSA Group, Toronto, ON, Canada, 301 pp.
CAN/CSA S806, 2012, “Design and Construction of Building Components with Fiber-Reinforced Polymers,” CSA Group, Toronto, ON, Canada, 208 pp.
Cheng, M. Y.; Hung, S. C.; Lequesne, R. D.; and Lepage, A., 2016, “Earthquake-Resistant Squat Walls Reinforced with High-Strength Steel,” ACI Structural Journal, V. 113, No. 5, Sept.-Oct., pp. 1065-1076. doi: 10.14359/51688825
Doostdar, H. M., 1994, “Behaviour and Design of Earthquake Resistant Low-Rise Shear Walls,” PhD thesis, University of Ottawa, Ottawa, ON, Canada, 274 pp.
Foster, S. J., and Gilbert, R. I., 1996, “The Design of Nonflexural Members with Normal and High-Strength Concretes,” ACI Structural Journal, V. 93, No. 1, Jan.-Feb., pp. 3-10.
Ghomi, S. K., and El-Salakawy, E., 2019, “Seismic Behavior of GFRP-Reinforced Concrete Interior Beam-Column-Slab Subassemblies,” Journal of Composites for Construction, ASCE, V. 23, No. 6, p. 04019047. doi: 10.1061/(ASCE)CC.1943-5614.0000980
Hiraishi, H., 1984, “Evaluation of Shear and Flexural Deformations of Flexural Type Shear Walls,” Bulletin of the New Zealand Society for Earthquake Engineering, V. 17, No. 2, pp. 135-144. doi: 10.5459/bnzsee.17.2.135-144
Hwang, S. J.; Fang, W. H.; Lee, H. J.; and Yu, H. W., 2001, “Analytical Model for Predicting Shear Strength of Squat Walls,” Journal of Structural Engineering, ASCE, V. 127, No. 1, pp. 43-50. doi: 10.1061/(ASCE)0733-9445(2001)127:1(43)
Kharal, Z., and Sheikh, A. S., 2020, “Seismic Behavior of Square and Circular Concrete Columns with GFRP Reinforcement,” Journal of Composites for Construction, ASCE, V. 24, No. 1, p. 04019059. doi: 10.1061/(ASCE)CC.1943-5614.0000988
Kim, J. H., and Mander, J. B., 1999, “Truss Modeling of Reinforced Concrete Shear-Flexure Behavior,” Report No. MCEER-99-0005, State University of New York at Buffalo, Buffalo, NY, 210 pp.
Mestyanek, J. M., 1986, “The Earthquake Resistance of Reinforced Concrete Structural Walls of Limited Ductility,” PhD thesis, University of Canterbury, Christchurch, New Zealand, 263 pp.
Mohamed, N.; Farghaly, A. S.; Benmokrane, B.; and Neale, K. W., 2014a, “Experimental Investigation of Concrete Shear Walls Reinforced with Glass Fiber-Reinforced Bars under Lateral Cyclic Loading,” Journal of Composites for Construction, ASCE, V. 18, No. 3, p. A4014001. doi: 10.1061/(ASCE)CC.1943-5614.0000393
Mohamed, N.; Farghaly, A. S.; Benmokrane, B.; and Neale, K. W., 2014b, “Flexure and Shear Deformation of GFRP-Reinforced Shear Walls,” Journal of Composites for Construction, ASCE, V. 18, No. 2, p. 04013044.doi: 10.1061/(ASCE)CC.1943-5614.0000444
Mun, J. H., and Yang, K. H., 2016, “Load Capacity of Squat RC Shear Walls by Strut-and-Tie Model,” Magazine of Concrete Research, V. 68, No. 24, pp. 1265-1277. doi: 10.1680/jmacr.15.00523
Mun, J. H.; Yang, K. H.; and Song, J. K., 2017, “Shear Behavior of Squat Heavyweight Concrete Shear Walls with Construction Joints,” ACI Structural Journal, V. 114, No. 4, July-Aug., pp. 1019-1029. doi: 10.14359/51689785
Park, H. G.; Baek, J. W.; Lee, J. H.; and Shin, H. M., 2015, “Cyclic Loading Tests for Shear Strength of Low-Rise Reinforced Concrete Walls with Grade 550 MPa Bars,” ACI Structural Journal, V. 112, No. 3, May-June, pp. 299-310. doi: 10.14359/51687406
Pilette, C. F., 1987, “Behavior of Earthquake Resistant Squat Shear Walls,” MSc thesis, University of Ottawa, Ottawa, ON, Canada, 195 pp.
Pultrall Inc., 2018, “Data Sheet—V-ROD GFRP rebars,” Thetford Mines, Quebec, QC, Canada.
Sánchez-Alejandre, A., and Alcocer, S. M., 2010, “Shear Strength of Squat Reinforced Concrete Walls Subjected to Earthquake Loading—Trends and Models,” Engineering Structures, V. 32, No. 8, pp. 2466-2476. doi: 10.1016/j.engstruct.2010.04.022
Sanchez, L. M. M., 2006, “RC Wall Shear-Flexure Interaction: Analytical and Experimental Responses,” PhD thesis, University of California, Los Angeles, Los Angeles, CA, 308 pp.
Shabana, I.; Farghaly, A. S.; and Benmokrane, B., 2021, “Effect of the Axial Load and Web Reinforcement Ratio on the Seismic Behavior of GFRP-RC Squat Walls,” ACI Structural Journal, V. 118, No. 4, July, pp. 109-121.
Sharifi, M., and Shafieian, M., 2018, “Effective Stiffness of Concrete Shear Walls Based on Statistical Analysis,” Journal of Structural Control, V. 19, No. 6, pp. 1560-1576.
Terzioglu, T.; Orakcal, K.; and Massone, L. M., 2018, “Cyclic Lateral Load Behavior of Squat Reinforced Concrete Walls,” Engineering Structures, V. 160, pp. 147-160. doi: 10.1016/j.engstruct.2018.01.024
Vecchio, F. J., and Collins, M. P., 1986, “The Modified Compression-Field Theory for Reinforced Concrete Elements Subjected to Shear,” ACI Journal Proceedings, V. 83, No. 2, Mar.-Apr., pp. 219-231.
Wasiewics, Z. F., 1988, “Sliding Shear in Low Rise Shear Walls Under Lateral Load Reversals,” MSc thesis, University of Ottawa, Ottawa, ON, Canada, 144 pp.
Whyte, C. A., and Stojadinovic, B., 2013, “Hybrid Simulation of the Seismic Response of Squat Reinforced Concrete Shear Walls,” Report No. 2013/02, PEER Center, University of California, Berkeley, Berkeley, CA, 196 pp.