الفهرس 
GENERALOnly 14 pages are availabe for public view
 |  | from | 210 |  |  |
| | | from | 210 | | |
Abstract
Traditional masonry buildings still present an important part of the existing building stock in many regions in Egypt. However, most of these buildings were not designed to meet the modern code requirements. This is basically, attributed to converting old building to new uses of occupancies design and construction faults of degradation happening in these structures due to insufficient maintenance for these reasons, these Buildings may need rehabilitation.
In this study, non-linear 3D numerical analyses were performed to investigate the efficiency of using ferrocement laminates in strengthening masonry walls to resist lateral loads. Verification models have been carried out by simulating available experimental data. A total of 77 models was analyzed and examined numerically by the 3-D nonlinear finite element package (ANSYS 15). The walls were built using concrete bricks and were tested under uniform axial vertical load and lateral load using Square wire mesh. The dimensions of proposed wall models were 1000*1000*250 mm. Different parameters were taken into consideration during this study; thickness of ferrocement layer (15, 20, 25, and 30 mm), steel mesh-fabric (0, 1, 2, 3, and 4 per face), compressive strength of mortar (20, 40, 60, and 90 MPa),and ferrocement layer location.
The numerical results of the strengthened walls demonstrated that, ferrocement laminates can be successfully used for increasing the ultimate carrying capacity, strength, energy absorption, and stiffness of masonry wall. The ferrocement thickness has a great influence on the amount of gain in ultimate load capacity, stiffness, energy absorption, and Ductility. It was observed that the ultimate lateral load and uncracked stiffness of strengthened models were increased respectively by about 160%, 310%, of the un-retrofitted wall.
Based on numerical results it is suggested an equation to predict the ultimate lateral load resist by ferrocement. The results of the finite element gave satisfactory agreement with the prediction equation ones. The finite element results of the ultimate lateral loads of strengthened walls with ferrocement succeed to achieve about 98% of the analytical results. Generally, The ANSYS program and predicted formula can be utilized to determine the effect of variables not studied experimentally.
In chapter 5, a total of 26 numerical simulations have been conducted using Seismo-Struct package. Four main parameters with regard to the main properties of ferrocement were studied: two different thicknesses of the mortar layer (20 and 25 mm), two different types of mortar strength (30 and 40 MPa), three values of number of wire meshes (1, 2, and 3), and two types of brick (clay and concrete) were considered. The ultimate strength is considerably enhanced by increasing the ferrocement laminate thickness and steel mesh-fabric. The retrofitted walls were not only restored the original ultimate load but also showed higher ultimate load compared to the control specimen. Also, increasing the mortar compressive strength increases both the ultimate load carrying capacity and displacement. It can be seen that the uncracked stiffness increases with increasing ferrocement thickness and number of wire meshes. Strengthening wall by ferrocement laminates of thickness 25 mm lead to increasing the total wall thickness and consequently increases the load-carrying capacity up to 121%.