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This paper presents the behavior of composite slabs with different geometry of profile steel sheet where the strength of composite deck slab mainly depending on the composite action and strength of the connection between concrete and profile steel sheet. In this study, three full-scale specimens of composite slabs with different types of geometry of profile steel sheets (T-shape, triangle shape and trapezoidal shape) were cast and tested under two-point load in order to evaluate the structural behavior and shear bond of composite slabs. The results show that geometry of profile steel sheet have significantly effect on the behavior and strength of composite slab where the ultimate load increased by (32% and 133%) in composite slabs with (triangle shape and T-shape) respectively as compared with trapezoidal shape. As well as the results were satisfy in term of deflection, horizontal end slip, strain and mode of failure.

The accumulation of rubber tires poses a great danger to the environment, especially since the number of cars is constantly increasing. Therefore, at the beginning work was done to recycle these tires and use them as an alternative to the natural aggregate used in concrete. It was also used in asphalt used in roads. Packaging for the Shear Connecter used in composite section. As this work gave excellent results in reducing the hardness of the shaker contactor, increasing its durability and resistance, and also preserving it from corrosion by rust. Waste rubber was also used to covering the bolts used to connect the beam with the column in steel structures. Where the presence of rubber gave a high ability to dissipate energy when the steel structure is subjected to a seismic load. It also worked to increase the displacement and increase the durability of the steel structure and also reduce the friction between the bolts and their holes. The presence of rubber around the bolt also delayed the failure time of the steel structure and thus the important aim of the research work has been achieved, which is to maintain the safety of people when the structure is exposed to an earthquake load.

Near surface mounted (NSM) is a promising strengthening technique for improving the flexural, shear and torsional strength of structures. Epoxy is the adhesive material used in this technique, but, the rapid failure happened in the mechanical properties of the epoxy matrix at high temperature, and the dangerous effects of epoxy fumes on the workers made the need of replacing epoxy with a new sustainable adhesive. Geopolymer Paste Adhesive and Modified Geopolymer Paste Adhesive were used in this study as adhesive materials in NSM strengthening technique to be an alternative to epoxy, where the geopolymer is a sustainable, environmentally friendly and less expensive material than epoxy. More importantly, it can better work at high temperatures. The test results showed that the modified geopolymer paste adhesive beat the epoxy adhesive by (4.1)% when adding (1)% micro steel fiber and (9.6)% when adding (0.6)% carbon fiber, while the bond strength reaches to (93)% of epoxy adhesive when adding (0.6)% polypropylene fiber.

This research presents an experimental study to investigate the role of shear span-to-depth (a/d) ratio for the cross-sectional area of reinforced concrete beam on the deflection in reinforced concrete beams (deep and normal beams), when the value of shear span-to-depth ratio (a/d) equal to (1, 2, 3, and 4) respectively, the behavior of deep beams is significantly different from that of normal beams. Because of their proportions, deep beams are likely to have strength controlled by shear. The a/d ratio is to have a very significant role on the deflection where the values of a/d < 2 (deep beam) and the value of a/d > 2 (normal beam) according to (ACI 318-08) with the constant reinforcement ratio ρ The experimental program included casting and testing four beams with a constant width of cross section (b = 250 mm) and reinforcement ratio ρ. Also, all models of beams tested under two-point loads. The results showed that the percentage of average increasing in value of deflection in normal beam (a/d > 2) 1.68 % from value of deflection in deep beam (a/d < 2). Also, the gained deflection due to load in ranges from (10 to 110 kN) increase by (31.64 %) when a/d > 2 in TB1. moreover, the deflection due to load in ranges from (10 to 190 kN) increase by (21.28 %) when a/d < 2 in TB2. Furthermore, the gained deflection due to load in ranges from (10 to 360 kN) increase by (21.21 %) when a/d < 2 in TB3. as well as, in this research studied the role of shear span-to-effective depth ratio (a/d) on the crack width and the number of cracks.

Shear tab connections are some of the most and simplest connections are used on steel constriction. The behavior of shear tabs under conventional loads are studied, but, the behavior of shear tabs become complex under companied loads axial and shear forces and moment. The connection should be sufficient ductile rotation to resist the unexpected force when the structures are exposed such as earthquake or wind load. The aim of this study is tested six steel portal frames. Three specimens are tested under horizontal cyclic load-quasi static load and other three specimens are verified under inclined cyclic load – quasi-static load. The connections of specimens are developed by using composites steel bolt/rubber are instead of conventional steel bolts for bolted the shear tab connections at the web of the beam. The composite steel bolts/rubber with different diameters are made of steel bolts covered by rubber taken from the old and wasted tires. Enhanced in the steel connections were cleared by increasing the resistance of these steel frames during the test as well as the tests are investigated that the effect of the inclined cyclic load is more influential than horizontal cyclic load.

This study scoped to develop the connections of steel structures using composite steel bolts/rubber to connect beam-to columns joints of steel structures instead of conventional steel bolts. Four steel plane portal frames were tested under horizontal cyclic quasi-static load. The study included testing different diameters of composite steel bolts/rubber: 0.5dbolt , 1.0dbolt , and 1.5dbolt , that are used to connect the beam with columns and these results were compared with traditional beam-to columns connections without rubber. The rubberized connections are working at high structural standards through reducing the effect of the stresses resulting from the earthquakes by absorbing damping process. They protect the bolts that are used in joints of steel structures from corrosion due to friction, and they are economically feasible because the rubber that was used for covering the bolts is taken from old tires. The experimental tests proved that using the rubber material around the bolts as much as one - half times bolt diameter raises the specimen’s resistance by 166.66%, increases the displacement by 163.30%, and reduces the strain by 48.13%, as compared with bolts that do not have a rubber (steel bolts only). All these results will be discussed in detail in this report.