ao"length of opening dh, dl"distance from top of steel section to centroid of concrete force at high and low moment ends of the opening, respectively dr"distance from outside edge of flange to centroid of reinforcement *b"maximum bending deflection for unperforated beam *m,b"maximum bending deflection for a member with an opening Fy"yield stress of steel FM y"reduced axial strength of steel in ...

neither damage mechanics model nor elastoplastic constitutive law can solely describe the behavior of concrete satisfactorily. in fact, they both fail to represent proper unloading slopes during cyclic loading. to overcome the disadvantages of pure plastic models and pure damage approaches, the combined effects need to be considered. in this regard, various classes of plastic-damage models have...

Precast concrete structures in Iran are generally designed as continuous columns with hinged beams, thereby making them simple frames. In this system in site show walls in two directions of buildings guaranteed lateral resisting system. However, in order to obtain a seismic resisting frame, the connection between beam and column should be moment resisting and ductile, allowing the formation of ...

Automated optic inspection of concrete aggregates for pollutants (e.g. wood, plastics, gypsum and brick) is required to establish the suitability for reuse in new concrete products. Inspection is more efficient when directly sampling the materials on the conveyor belt instead of feeding them in a sampled stream to the sensor system. However, this does not reveal the true volume contents if the ...

This paper presents a study on interfacial stresses of a concrete column confined by fiber-reinforced plastic (FRP) plate, which has been widely applied in the civil engineering for rehabilitation and retrofitting of conventional structures. It is assumed that both the FRP plate and concrete structures are elastic and the interface between them is perfectly bonded. An analytical model for analy...

an analytical nonlinear stress-strain model and a microscopic damage index for confined and unconfined concretes together with a macroscopic damage index for reinforced concrete (rc) structures under cyclic loading are proposed. in order to eliminate the problem of scale effect, an adjustable finite element computer program was generated to simulate rc structures subjected to cyclic loading. by...