Mr. Enea Mustafaraj was awarded the degree: PhD in Civil Engineering
July 3rd, 2016
On June 16, 2016, Mr. Enea Mustafaraj, Lecturer at the Department of Civil Engineering, has been conferred the PhD degree by Epoka University. His study entitled "External shear strengthening of unreinforced damaged masonry walls" was related to improvement of structural performance of unreinforced masonry walls using various strengthening techniques. Mr. Mustafaraj is the first PhD student graduated from the department of Civil Engineering of Epoka University.
We wish every success to Dr. Mustafaraj in his future academic career and professional engagements.
Below you may find some details related to his research:
Title: EXTERNAL SHEAR STRENGTHENING OF UNREINFORCED DAMAGED MASONRY WALLS
Author: Enea MUSTAFARAJ
Thesis Supervisor: Assoc. Prof. Dr. Yavuz YARDIM
Unreinfroced masonry (URM) buildings are one of the most used construction types in the world. Due to the limited capacity to sustain lateral loads, particularly seismic actions, all this building stock is suspectible to damages in the case of an earthquake.
In this study, it is presented the experimental campaign on investigation of structural performance of masonry walls by conducting diagonal compression tests and finite element modelling. A total of 52 diagonal compression tests were conducted in laboratory on 38 specimens of nominal dimensions of 1.2 x 1.2 x 0.25 m. The primary objective was to investigate the structural behavior of three main specimen types: unreinforced, strengthened and repaired masonry panels. Four different strengthening techniques such as ferrocement jacketing (FC), textile reinforced mortar (TRM), glass fiber reinforced polymer (G-FRP) mesh and carbon fiber reinforced polymer (C-FRP) wrap have been used and the structural performance of the panels has been evaluated and compared among each other. The panels were made of two different type of mortars; type “N” representing the modern masonry buildings and type “O” mortars for old buildings of 1950-60s and earlier.
A special attention is paid on the pre-cracked or the so-called damaged panels. After the plain panels were tested until failure, they were repaired using the strengthening methods as ferrocement jacketing, polypropylene plastering and C-FRP repair. The results among these techniques were compared in terms of increment of improvement in shear strength, drift, as well as energy dissipation.
It was observed that ferrocement jacketing technique, after repairing of the pre-cracked panels, increased the shear strength by 179-476% and ductility 388-1193%.
Additionally, the plain and strengthened panels with ferrocement jacketing and polypropylene reinforced mortar were modelled using discrete micro-modelling of DIANA 9.6 commercial software and a non-linear analysis was conducted for each case. The modelling results showed a good match of experimental and analysis results, highlighting the ferrocement jacketing technique as the most effective one.
As a result, the strengthening techniques had a considerable improvement in shear strength and defromation capacity. The maximum improvement for both, shear strength and ultimate drift was achieved by ferrocemnt jacketing, 511% and 576% respectively, occrring in panles of Series 2.
At the end of campagin, it was observed that ferrocement jacketing technique apart from increase in shear strength, improved considerably the deformation capacity of the wall specimens in both cases; repaired panels as well as undamaged ones.
Keywords: unreinforced masonry, strengthening, ferrocement jacketing, textile reinforced mortar, fiber reinforced polymers, diagonal compression test, finite element modelling