Comparative Study of T-beam Bridge Longitudinal Girder Design using IRC 112:2011 and IRC 21:2000

T-beam Bridge is composite concrete structure which is composed of slab panel, longitudinal girder and cross girder. Present study is mainly focuses design of longitudinal girder by IRC: 112-2011 and IRC: 21-2000. In India, till now girders are designed and constructed according to Indian road congress guidelines as per IRC: 21-2000 code in which working stress method is used. Recently Indian road congress has introduced another code IRC: 112-2011 for design of prestressed and RCC bridges using limit state method. In regards to this, present study has been performed to know how design of IRC-112 differs from IRC-21 and an attempt is made to study undefined parameters of IRC: 112-2011 such as span to depth (L/d) ratio. Present study is performed on design of longitudinal girder using "working stress method" using IRC: 21-2000 and limit state method using IRC: 112-2011 code specifications. It is observed that L/d ratio of 10 in working stress method and L/d ratio of 14 in limit state method is most preferable. Quantity of materials required in limit state method is compared with quantity of material required in working stress method and it is found that concrete can be saved up to 25 to 30% using limit state method.