Flexural Behaviour of External Reinforced Concrete Beams

Most of highway bridge structure elements are constructed using concrete structures such as deck, girders and piers. Especially on girder beams, concrete structural elements that work optimally resist bending is a part of the outermost fibers on the compression side while the concrete on the tensile side is negligible. Therefore it is understandable that the concrete on compression section of a concrete beam should be optimized while the concrete on tension section should be minimized. This may cause the reducing of the self-weight of the concrete structures as well as the using of the concrete materials can be reduced. As an experimental effort to achieve the above consideration, a series of study is being done in reducing the volume of concrete on tension parts. In order to clarify the flexural capacity of beam without concrete on the tension part (External reinforced concrete beam, ERCB), an experimental flexural test was carried out. The specimens are beams with a length of 2700 mm, width of 150 mm and 200 mm high. The beams were supported by a simple supports with span of 2500 mm and it was subjected to monotonic two loading points. The results indicated that the flexural capacity of ERCB decreased to 86%, compared to the control specimens. Additionally, the stiffness of the ERCB also decreased to 60% compared to the normal beams.