الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Reinforced concrete structures throughout the world are frequently subjected to greater challenges such as change of use, increase in the existing loads, and durability of aging structures. For that, rehabitation, maintenance, and upgrading of structural members are more suitable ways for increasing the serviceability of structural members. Numerous structures designed according to the older design codes around the world are deemed unsafe according to the new design codes due to increased loads and other considerations. To replace these deficient structures by new buildings requires a large amount of time, and funding. Strengthening has become more desired way of increasing the load capacity and extending the service live of these structures. Infrastructure decay caused by premature deterioration of buildings and structures has led led led led to the investigation of several processes for repairing or strengthening purposes. To coup with the great structural demands, many attempts of repairing and retrofitting methods have been developed to increase strength of RC beams. The recent research was conducted to study the flexural and shear behavior of R.C beams that was strengthened externally by sprayed polyurea system and study the effectiveness of changing the thickness of polyurea. The technique of polyurea system to strength of R.C beams was investigated in order to evaluate system in increasing the flexure and shear capacity of beams. Small and large scale specimens of beams were used. Different strengthening schemes for beams were used with variable thickness of polyurea. Sixteen specimens were prepared and where divided to six flexural beams and ten shear beams and tested according to variable of study. The experimental measurements included ultimate load, vertical deflection along the beams, overall ductility, and containing fragmentation. The polyurea system showed measurable increasing in flexure and shear capacity of beams. The ductility of beams was increased. The ability of containing fragmentation was clearly achieved by polyurea coating.