STRUCTURAL PARAMETRIC STUDY ON PRESTRESSED CONCRETE BEAM WITH HIGH STRENGTH STIRRUPS BY USING FEM

Advisor: Dr. Badrinarayan Rath

The concrete is weak in tension and the tension cracks develop at the bottom of the beam which causes the failure, so the Prestressed concrete refers to a technology designed to apply enough pre-compression in the concrete beam by tensioned steel wires, cables, or rods so, under operating conditions, the concrete has no tensile stresses or the tensile stresses are so low that little to no visual cracking occurs. This thesis presents a Structural Parametric Study on Prestressed Concrete Beam with High Strength Stirrups by Simulating FEM. The finite element models on ABAQUS are validated with the experimental results of five beams having Yield Strength of Stirrup 420MPa, 535MPa, 675MPa subjected to three-point bending and that of a beam subjected to point load. The validated models are used to investigate the influence of the shear span to depth ratios, eccentricity, shear reinforcement ratio and the prestressing force on the beam capacity. The structural behaviors like deflection, flexural strength, failure mode with crack propagation and shear strength of PSC and RCC beam has been analyzed by using ABAQUS. The cross section of beam is (450 x 860 x 3000) mm and (450 x 600 x 3000) has performed by using ABAQUS for testing structural behavior. The numerical results are shown within 3.5% range for PSC and 5.4% for RCC of accuracy in comparison to the experimental results. The analysis indicates that the flexural strength of the beams is inversely dependent on the eccentricity. When a/d ratio reduces the deformability of the beams reduced, while the post-cracking of the beams is decrease due to shear reinforcement ratio increasing. The analysis indicates that the shear capacity and crack width of the beams is dependent on the shear reinforcement ratio. It also shows that the average increase in the shear capacities is 53.5% for PSC beam and 32% increase for RCC beam when the a/d ratios decreased from 5.0 to 3.5. Finally the percentage of increment in shear strength for PSC beam specimen will be equal to the percentage of decrement of shear reinforcement so prestressed concrete with high strength steel minimized a large number of stirrups substitute by prestressed concrete. Keywords: Prestressed Concrete Beam, Reinforced Concrete Beam, High Strength Stirrups, Finite Elment Method.