Experimental study on seismic behavior of damaged Unreinforced Masonry Walls retrofitted by concrete vertical ties and bed rebar with and without shotcrete

Rismanian Yazdi, Batool; Javaheri Tafti, Mohamadreza; Mirjalili, Alireza

doi:10.22065/jsce.2023.385394.3042

Experimental study on seismic behavior of damaged Unreinforced Masonry Walls retrofitted by concrete vertical ties and bed rebar with and without shotcrete

Document Type : Original Article

Authors

Batool Rismanian Yazdi ¹

mohamadreza javaheri tafti ²

alireza mirjalili ³

¹ Ph.D. Candidate. Department of Civil Engineering, Taft Branch, Islamic Azad University, Taft, Iran

² Assistant Professor. Department of Civil Engineering, Taft Branch, Islamic Azad University, Taft, Iran

³ Assistant Professor. Department of Civil Engineering, Yazd Branch, Islamic Azad University, Yazd, Iran

10.22065/jsce.2023.385394.3042

Abstract

The present article describes experimental procedures to investigate the seismic retrofitting techniques used for damaged unreinforced masonry (URM) walls. In total, three tests were performed on a full-scale wall under constant vertical load, along with lateral loading according to the loading protocol. The wall was built similarly to the walls of typical masonry buildings in Iran. The unreinforced wall was tested as a reference sample. Then, the damaged sample was retrofitted with two vertical concrete ties and bed rebar on one side and retested. Finally, the damaged sample was repaired with shotcrete on two sides and tested. The experimental results showed that strengthening the damaged unreinforced wall with the vertical concrete ties and bed rebar not only restored most of the original seismic characteristics of the wall but also significantly improved the seismic behavior of the wall. Moreover, improving seismic characteristics, the retrofitting by vertical concrete ties, bed rebar, and two-side shotcrete increased wall energy absorption capacity. The experimental results showed that by repairing the damaged wall with vertical concrete ties and bed rebar, the lateral resistance increased by 219%. and by repairing the damaged wall with vertical concrete ties, bed rebar, and both side shotcrete, the lateral resistance increased by 464%.

Keywords

Damaged unreinforced masonry walls

Vertical concrete ties

Bed rebar

Shotcrete

Seismic retrofit

Subjects

Repair, Rehabilitation and Retrofit of Structures

[1] Elgawady M, Letuzzi P, Badoux M (2004) A review of conventional seismic retrofitting techniques for URM. In: 13th international brick and block masonry conference, Amsterdam.

[2] Wilding BV, Beyer K (2016) Force–displacement response of in-plane loaded unreinforced brick masonry walls: the critical diagonal crack model. Bull Earthq Eng 15:2201–2244.

[3] Shabdin, M., Zargaran, M. and Attari, N. K. A. [2018c] “Experimental diagonal tension (shear) test of Unreinforced Masonry (URM) walls strengthened with textile reinforced mortar (TRM),” doi: 10.1016/j.conbuildmat.2017.12.234.

[4] Toranzo, L. A., Restrepo, J. I., Mander, J. B. and Carr, A. J. [2009] “Shake-table tests of confined-masonry rocking walls with supplementary hysteretic damping,” Journal of Earthquake Engineering 13(6), 882–898. doi:10.1080/13632460802715040.

[5] M.T. Shedid, W.W. El-Dakhakhni, R.G. Drysdale, Alternative strategies to enhance the seismic performance of reinforced concrete-block shear wall systems, J. Struct. Eng. 136 (6) (2009 Nov 21) 676–689.

[6] T. Kasparik, M.J. Tait, W.W. El-Dakhakhni, Seismic performance assessment of partially grouted, nominally reinforced concrete masonry structural walls using shake table testing, J. Perform. Constr. Facil. 28 (2) (2012 Nov 3) 216–227.

[7] Tso WK, Rutenberg A, Heidebrecht AC. Cyclic loading of externally reinforced masonry walls confined by frames. Canadian Journal of Civil Engineering 1975, 2(4):489–493.

[8] Kazemi MT, Hoseinzadeh Asl M, Bakhshi A, Rahimzadeh Rofooei F. Shaking table study of a full-scale signle storey confined brick masonry building. Scientia Iranica 2010, 17(3):184–193.

[9] Gouveia, J. P., & Lourenço, P. B. (2007). Masonry shear walls subjected to cyclic loading: influence of confinement and horizontal reinforcement. 10th North americal masonry conference, St. Louis, Missouri, USA.

[10] Sarrafi B, Eshghi S. Behavior of clay brick confined masonry walls under cyclic loads. TMS Journal 2012; 7–19.

[11] Hori N, Inoue N, Purushotam D, Nishida T, Kobayashi J. Experimental and analytical studies on earthquake resisting behaviour of confined concrete block masonry structures. Earthquake Engineering & Structural Dynamics 2006, 35(13):1699–1719.

[12] Yekrangnia M, Bakhshi A, Ghannad M.A., Force-displacement model for solid confined masonry walls with shear-dominated failure mode.

[13] D. Zhou, Z. Lei, J. Wang, In-plane behavior of seismically damaged masonry walls repaired with external BFRP, Compos. Struct. 102 (2013) 9–19.

[14] H. Santa-Maria, P. Alcaino, Repair of in-plane shear damaged masonry walls with external FRP, Constr. Build. Mater.25 (3) (2011) 1172-1180.

[15] H. Santa-Maria, E. Mustafaraja, Y. Yardimb, Retrofitting damaged unreinforced masonry using external shear

strengthening techniques, https://doi.org/10.1016/j.jobe.2019.100913.

[16] Ehteshami Moeini, M., Razavi, S. A., Yekrangnia, M., Pourasgari, P., & Abbasian, N. (2022). Cyclic performance assessment of damaged unreinforced masonry walls repaired with steel mesh reinforced shotcrete. Engineering Structures, 253, 113747. https://doi.org/10.1016/j.engstruct.2021.113747.

[17] Ghezelbash, A., Beyer, K., Dolatshahi, K. M., & Yekrangnia, M. (2020). Shake table test of a masonry building retrofitted with shotcrete. Engineering Structures, 219, 110912. https://doi.org/10.1016/j.engstruct.2020.110912.

[18] Mardani, A., Dehkordi, M.R., Moghadam, A.S., & Yekrangnia, M. (2019). Example of a Two-Story Unreinforced Masonry Building Retrofitted by Shotcrete. Advanced Design Examples of Seismic Retrofit of Structures.

[19] BS EN ISO 60 (2000) Plastics-Determination of apparent density of material that can be poured from a specified funnel , British Standard. https://standards.iteh.ai/catalog/standards/sist/d32e9ed0-5009-45f0-83b7- 8290915c8383/sist-iso-601996

[20] ASTM C-67-00 (2002) Standard test methods for sampling and testing brick and structural clay tile. ASTM International, West Conshohocken. www.astm.org.

[21] ASTM C109/C109M-16a (2016) Standard test method for compressive strength of hydraulic cement mortars (using 2-in. or [50 mm] cube specimens). ASTM International, West Conshohocken. www.astm.org.

[22] Harris, H. G. and Sabnis, G. [1999] Structural Modeling and Experimental Techniques, second Edition, CRC Press, Boca Raton, FL.

[23] ASTM C1314-02A. Standard test method for compressive strength of masonry prisms. American Society for Testing and Materials; 2002.

[24] ASTM C39/C39M-99 (2000) Standard test method for compressive strength of cylindrical concrete specimens. ASTM International, West Conshohocken. www.astm.org.

[25] ACI 374.1-05 (2019) Acceptance Criteria for Moment Frames Based on Structural Testing and Commentary: an ACI standard: an ACI report. A. C. I. Committee 374, American Concrete Institute.

[26] FEMA-356. Pre standard and commentary for the seismic rehabilitation of buildings. Washington (DC): Federal Emergency Management Agency; 2000.

[27] ASCE. Seismic rehabilitation of existing buildings – SEI/ASCE 41-06. Reston. Va.: American Society of Civil Engineers; 2007.