Environmental Studies and Researches Institute, University of Sadat City, Egypt

Reinforced concrete deep beams may exist in many structural applications such as offshore structures,
transfer girders, pile caps, tall buildings and water tanks. The depth of deep beams is much greater
than normal in relation to their span. Since the beam is short in this case, shear deformations are more
important and special design methods should be applied in this case rather than normal beam theory.
Continuous deep beams are defined in the Egyptian Code of Practice (2012) [2]as those beams whose
height to effective span ratio greater than 0.4. Deep beams are members with special features. In such
beams, plane sections do not remain plane after bending, with significant warping of the crosssections
because of high shear stresses. The resulting strain distribution is no longer linear and
flexural stresses are not linearly distributed even in the elastic range. Recently, high strength
concrete, defined by the American Concrete Institute ACI318-08[3], as concrete with cylinder
compressive strength greater than 60Mpa, is being widely used in the construction industry.
However, limited research efforts were directed towards the study of the behavior and shear strength
of reinforced high strength concrete continuous deep beams. Furthermore, sometimes web openings
have to be provided in deep beams for the purpose of access or for providing services. The presence
of such openings may affect the shear strength of deep beams. However, limited investigations were
directed towards the study of continuous deep beams with openings. Also, strengthening simply
supported deep beams using carbon fiber reinforced polymers (CFRP) was investigated by many
researchers. However, limited research papers were directed towards CFRP strengthening of
continuous deep beams. Experimental tests have been carried out on rectangular reinforced concrete
continuous deep beams with a/d=1.17, under static loading up to failure. The study takes into
consideration the following parameters: Percentage of web reinforcement (ρh), Positions of
openings and number of openings. Also, strengthening of openings in continuous deep beams using
glass fiber reinforced polymer (GFRP) was studied in this research. Test results indicated that the
presence of web openings within exterior or interior shear spans had great effect on the beam
capacity and its behavior. Existence of web openings within exterior or interior shear spans caused a
high reduction in the shear capacity of the beams by about 35%. Therefore and whenever should be 
kept clear of the natural load path joining the loading and reaction points (solid) free from openings.
Also, the strengthening of openings contains the cracks and increase the crack and ultimate load.
Finally we will compare the test results with the theoretical values for beam A1 which were evaluated
using strut and tie analysis according to Egyptian code (2012). The strut–and tie method can be used for
the design of Disturbed regions (D- regions) of structures where the basic assumption of flexure theory
namely plane sections remaining discontinuities arising from concentrated forces or reactions and near
geometric discontinuities such as abrupt changes in cross section etc. The strut – and- tie method of
design is based on the assumption that the D-regions in concrete structures can be analyzed and design
using hypothetical pin-jointed trusses consisting of struts and ties interconnected at nodes. The usual
design practice for continuous deep beams has been to employ empirical equations which are invariably
based on simple span deep beams testes. Given the unique behavior pattern of continuous deep beams,
this practice is unreliable. Since continuous deep beams contain significant extents of D-regions and they
exhibit a marked truss or tied arch actions, the strut- and – tie method offers a rational basis for the
analysis and design of such beams. The mechanics and behavior of continuous deep beams are briefly
discussed from which a strut–and–tie model for such a beam is developed.