BEHAVIOR EVALUATION FOR DEEP BEAMS CONSIDERING CONDITION LOADED WITH CONCRETE COLUMN STUB AND BEARING PLATE, AND CONTRIBUTION OF STEEL DIAGONAL REINFORCEMENT

• Main Author: Ramli, Rahmat
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/37055
• Institution: Institut Teknologi Bandung

Deep Beams commonly found in tall building, offshore building, pile cap, or transfer beam. Deep beams have a shear span-effective depth ratio less than or equal to 2. In a structures known as beam regions and discontinuity region. In discontinuity region is distinguished into a force discontinuity and geometric discontinuity. Deep beams is designed using strut-and-tie model. One of the strut-and-tie method can be calculated based on ACI 318-14. ACI 318-14 defines the shear element on deep beams with concrete column stub or bearing plate based on force discontinuity, where in actual condition the shear span of deep beams with concrete column stub is determined based on geometric discontinuity. Deep beams that are prone to shear failure can be avoided by increasing their shear capacity using diagonal reinforcement parallel to the direction of diagonal strut. To prove the inaccuracy in determining the shear span of deep beams and show the addition of diagonal reinforcement parallel to the direction of diagonal strut will increase the shear capacity of deep beams, database of deep beams testing with concrete column stub is collected to be analyze and laboratory testing of 8 deep beams specimens. The result of the analysis from database and experimental showed that strength capacity of deep beams with determination shear element deep beams using concrete column stub based on geometric discontinuity approach to actual result. The experimental results of deep beams with concrete column stub have a greater strength capacity about 2,6%-8,8% and a greater deformability about 29,5%-43,3% from deep beams with bearing plate. Deep beams with smaller ratio of a/d (shear span-effective depth ratio) have a greater strength capacity about 37,5%-53,3% compared to deep beams with large ratio of a/d , but deep beams with large ratio of a/d have a greater deformability about 95,4%-116,2%. Deep beams with addition of diagonal reinforcement shows that the strength capacity increases compared deep beems without diagonal reinforcement about 10,6%-15,8% and deformability increasing about 82%-95,2%. Deep beams that are prone to shear failure, by addition diagonal reinforcement can change the failure mode to flexure failure.