Search results for "concrete beam"
showing 10 items of 41 documents
Flexural Response of RC Beams Failing in Shear
2020
In this paper, an analytical model to determine the flexural response of simply supported RC beams under four-point bending tests failing in flexure and shear is presented. The model is able to provide load-deflection curves, including also the shear contributions, which are determined assuming a kinematic rigid plastic model able to consider different strength contributions such as the concrete, the dowel action, and transverse reinforcement with progressive yielding. For each contribution, a physical explanation is provided to link the strength evaluation with a specific kinematic evolution for the determination of the overall response of RC beams under combined shear and flexural loads. …
Dissipative connections of rc frames with prefabricated steel-trussed-concrete beams
2020
In the last thirty years, Hybrid Steel-Trussed Concrete Beams (HSTCBs) have been widely used in civil and industrial constructions and, therefore, their mechanical performance must be evaluated with the aim of guaranteeing adequate dissipation of the seismic energy particularly in the beam-to-column joints. However, one of the most frequent peculiarities of HSTCBs is that of using their own steel joist to cover large spans with reduced depth and, in the case of traditional beam-to-column connections, this requires large amount of steel reinforcement inside the panel zone, often made with large diameter rebars. These characteristics make both the panel zone and the beam end potentially vulne…
Experimental characterization of friction properties of materials for innovative beam-to-column dissipative connection for low-damage RC structures
2023
Low-damage design of structures in seismic-prone areas is becoming an efficient strategy to obtain "earthquake-proof" buildings, i.e. buildings that, even in the case of severe seismic actions, experience a low or negligible amount of damage. Besides the safeguard of human lives, this design strategy aims also to limit the downtime of buildings, which represents a significant source of economic loss, and to ensure an immediate occupancy in the aftermath of an earthquake. In this context, focusing on moment-resisting frames (MRFs), several solutions have been developed for the beam-to-column connections (BCCs) of steel and precast/prestressed concrete structures, but very few for cast-in-sit…
Assessment of push-out test response of hybrid steel trussed-concrete beams by FE model
2013
Aiming to investigate the truss-concrete stress transfer mechanism in Hybrid Steel Trussed-Concrete Beams (HSTCBs), a three-dimensional nonlinear FE model is developed. The constitutive laws of the steel composing the plates and the bars is modeled by means of a quadri-linear law, while the concrete behavior is defined by means of a Concrete Damaged Plasticity (CDP) model, suitable for modeling concrete and brittle materials. The CDP model uses the concept of isotropic damaged elasticity in combination with isotropic tensile and compressive plasticity and is able to properly account for the concrete confinement effect. Two main failure mechanisms are considered, namely the tensile cracking …
Innovative connections for steel-concrete-trussed beams: a patented solution
2023
The most recent design strategies welcome the adoption of innovative techniques for seismic energy input mitigation, aiming to achieve high dissipation capacity, prevent the structure from collapse and ensure the serviceability of the construction. Friction damper devices have been widely adopted in framed steel structures for decades, while their introduction in different structural types is still under investigation. This paper presents the outcomes of innovative research supported by the industry and conducted on beam-to-column connections of RC structures in which the beams are Hybrid Steel-Trussed Concrete Beams (HSTCBs) and the columns are classical RC pillars. An innovative solution,…
Finite element modeling of the shear behavior of hybrid steel trussed concrete beams
2015
The development and calibration of a three-dimensional (3D) nonlinear Finite Element (FE) model is presented with the aim of investigating the shear behavior of steel-concrete composite beams realized with a steel truss embedded into a concrete core and named Hybrid Steel Trussed-Concrete Beams (HSTCBs). The model is calibrated on the results of a reference experimental campaign of three-point bending tests on HSTCBs realized at the Laboratory of Structures of the University of Palermo. The actual behavior at the steel-concrete interface has been introduced in the model through the implementa-tion of a cohesive constitutive relationship. Furthermore, the damaged plasticity of concrete has b…
Shear-flexure interaction of RC elements strengthened with FRP sheets
2005
An approximate physical model for evaluation of the M-V interaction resistance domains for concrete elements strengthened with FRP sheets is presented. The reliability of the model in predicting flexureshear capacity is verified by a comparison with the results of several experimental tests.
Seismic response of RC frames with HSTC beams endowed with friction damper devices
2019
The aim of this work is to compare the seismic response of RC frames built using Hybrid Steel-Trussed Concrete Beams (HSTCBs) whether or not equipped with friction damper devices installed at the beam-to-column joints. Due to their small depth-to-span ratios, HSTCBs usually lead to a large amount of rebar within the beam-column joint, potentially reducing its cyclic performance. Therefore, the adoption of a friction system at the beam-tocolumn joint provides two main advantages, i.e. limiting the shear forces, and thus the potential damage, in the panel zone thanks to the increasing of the bending moment lever arm, and assigning to the device the task of dissipating the incoming seismic ene…
Design of friction connections in R.C. structures with hybrid steel-trussed concrete beams
2019
In this work a feasibility study on the use of friction devices within beam-to-column joints of RC structures is conducted. The connection is made between RC columns cast in-situ and semi-prefabricated steel-concrete beams, named Hybrid Steel-Trussed-Concrete Beams (HSTCBs). Nowadays, HSTCBs are widely adopted in civil and industrial buildings and, therefore, it is required to evaluate their compliance with the capacity design criteria and their seismic energy dissipation capability. However, the design of the reinforcement of such beams usually lead to the adoption of large amount of steel within the panel zone which becomes potentially vulnerable to the effects of seismic cyclic actions a…