Abstract:
This study presents an analytical assessment for the reinforced concrete frame constructed with flat beams. The typology is known as frame with “embedded beam in the slab”, with a total height 25cm. Many similar structures have been constructed all around Balkans regions and Middle East. Sometime these structures have only in the perimeter the normal beam (thickness more than the slab). As it is well known the main advantages of using this type of reinforced concrete frames are that, they provide both, low economical cost for initial construction and a good architectural flexibility. Anyway in some literature, these types of structures are not recommended as being the only system for seismic forces resistance of a building.
The response of the frame with flat beams is compared with two other structural typologies, classical frame and uncoupled wall systems. Structures with 3 and 5 floors are selected for this analyse. The effect of infill masonry hallow clay bricks is also considered.
The criterions of comparisons are based mostly on Eurocode 8 and especially on damage limitation states. This criterion is chosen in this study due to the fact that this parameter is connected not simply to deformation but to the financial loss to. This investigation is made by using software ETABS. The investigation as was expected show that the frame with flat beams has much deformation than the classical frame and the uncoupled wall systems. The interstory drifts are much difficult to accommodate as per Eurocode 8 requirements. When infill walls are symmetrical in plan and well distributed in height the effect is positive in all structures. When are not continues on the ground story only the uncoupled wall systems represent consistent interstory drifts. Two other structural typologies are similar on their ability to present the negative effect of soft story.
