Flexural Capacity of the Concrete Beams Reinforced by Steel Truss System

Reinforced concrete beam is normally reinforced by steel bars to sustain tensile forces occurring due to flexural response, and vertical steel reinforcement to sustain shear stresses. On the other side, the truss system is a structure composed by triangle. Truss system develops its flexural capacity based on the inter-action of the bar elements. Therefore, introducing of the truss system to the reinforced concrete beams by modifying of the tensile and shear reinforcement may increase the beam flexural capacity. The study on the application of the truss system to the reinforced concrete beams has been conducted. The shear reinforcement was modified to form the triangles that were connected to the tensile reinforcement on the bottom and compressive reinforcement on the top. The steel bar elements were connected by welding to form a truss system. The effect of the buckling of the compression bar element on the truss system may be avoided due to the constrain effect of the surrounding concrete. In order to clarify the effect of the truss system reinforcement to the flexural behaviour, a series of specimens was prepared. The beams specimens have a length of 3.3 m with cross section of the 15 by 20 cm. A normal concrete beam was also prepared as control specimens. Results indicated that the concrete beams reinforced by truss system had flexural capacity higher than the normal beam.