Performance Analysis of Ferrocement Retrofitted Masonry Wall Units under Cyclic Loading

Authors: Raquib Ahsan, Md. Mahir Asif, Md. Zahidul Alam

Abstract:

A huge portion of old masonry buildings in Bangladesh are vulnerable to earthquake. In most of the cases these buildings contain unreinforced masonry wall which are most likely to be subjected to earthquake damages. Due to deterioration of mortar joint and aging, shear resistance of these unreinforced masonry walls dwindle. So, retrofitting of these old buildings has become an important issue. Among many researched and experimented techniques, ferrocement retrofitting can be a low cost technique in context of the economic condition of Bangladesh. This study aims at investigating the behavior of ferrocement retrofitted unconfined URM walls under different types of cyclic loading. Four 725 mm × 725 mm masonry wall units were prepared with bricks jointed by stretcher bond with 12.5 mm mortar between two adjacent layers of bricks. To compare the effectiveness of ferrocement retrofitting a particular type wire mesh was used in this experiment which is 20 gauge woven wire mesh with 12.5 mm × 12.5 mm square opening. After retrofitting with ferrocement these wall units were tested by applying cyclic deformation along the diagonals of the specimens. Then a comparative study was performed between the retrofitted specimens and control specimens for both partially reversed cyclic load condition and cyclic compression load condition. The experiment results show that ultimate load carrying capacities of ferrocement retrofitted specimens are 35% and 27% greater than the control specimen under partially reversed cyclic loading and cyclic compression respectively. And before failure the deformations of ferrocement retrofitted specimens are 43% and 33% greater than the control specimen under reversed cyclic loading and cyclic compression respectively. Therefore, the test results show that the ultimate load carrying capacity and ductility of ferrocement retrofitted specimens have improved.

Keywords: Cyclic compression, ferrocement, masonry wall, partially reversed cyclic load, retrofitting.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1474919

References:

[1] A. Dogangun, A. Ural, and R. Livaoglu, “Seismic performance of masonry buildings during recent earthquakes in Turkey,” The 14th World Conference on Earthquake Engineering, Beijing, China, Oct. 2008.
[2] D. N. Trikha, P. C. Sharma, and S. Johnson, “Rehabilitation of Corrosion-damaged steel tanks by ferrocement at University of Roorkee,” Proceeding of 3rd International Conference on Ferrocement, University of Roorkee, pp. 207-215, 1988.
[3] Kantharaju, K. Vasudev, S. Kulkarni, C. V. Chandrashekar, G. Rajappa, and N. G. Malji, “Ferrocement components for low cost housing in developing countries,” 26th Conference on Our World In Concrete & Structures, Singapore, Aug. 2001.
[4] G. Dass, and M. Talwar, “Review paper on ferrocement in construction,” International Journal of Advanced Research in Computer Science, vol. 8, no. 4, May 2017.
[5] A. M. Reinhorn, and S. P. Prawel, “Seismic retrofit of structural masonry using a ferrocement overlay,”Proceedings of the Third North American Masonry Conference. 1985.
[6] K. K. Singh, S. K. Kaushik, and A. Prakash, “An investigation of the ultimate and first crack strength of ferrocement in flexure,” Indian Concrete Journal, pp. 335-340 & 344, 1976.
[7] M. T. Hossain, “Experimental investigation on performance of interior beam column joints retrofitted with ferrocement and polyster fiber reinforced concrete,” M.Sc. Thesis, Department of Civil Engineering, BUET, Dhaka, 2015.
[8] BNBC (2017) “Bangladesh National Building Code”, Volume 2, Part 6-“Structural Design”, chapter 12–“Ferrocement structures”. To be published by Housing and Building Research Institute, Bangladesh.