Reinforced and Prestressed Concrete Hollow Beams Under Torsion

Abstract

Recently a new rational theoretical model for beams under torsion has been proposed. This model, called Softened Membrane Model for Torsion (SMMT), is able to predict well the global behaviour of reinforced and prestressed concrete solid beams under torsion. This paper presents a study in order to check the SMMT for reinforced and prestressed concrete hollow beams under torsion. Theoretical predictions from SMMT are compared to some experimental results of hollow beams available in the literature and also with the predictions of another theoretical model previously proposed from the authors. It is shown that SMMT, with some corrections, is able to predict satisfactorily the overall behaviour of reinforced and prestressed concrete hollow beams under torsion.

Effect of fibre aspect ratio on the torsional behaviour of steel fibre-reinforced normal weight concrete and lightweight concrete

“…The above-mentioned studies focused on the torsional characteristics of normal weight concrete (NWC), high strength concrete and high performance concrete; however, the investigation of the torsional strength of lightweight concrete (LWC) is limited. This is because the conventional torsional design from the ACI code is based on the skew bending theory [4], and then further theories including the Thin Tube theory, Variable Angle Truss Model and Softened Membrane Model were developed for the prediction of the torsional behaviour of concrete [2,4,11,12]. However, there are no studies available on the torsional behaviour of LWC.…”

Generalized Softened Variable Angle Truss Model for RC Hollow Beams under Torsion

“…It has been known for a long time that the concrete core has negligible effect on the torsional strength of RC beams [9]. However, from previous studies it was also observed that the cracking twist, cracking torque, torsional stiffness and torsional ductility of hollow beams are lower than those of solid beams [8,10,11,12,13]. In fact, when used to predict the torsional behavior of RC hollow beams under torsion, both GSVATM and SMMT show in general worst predictions with highest dispersion of the results, mainly for the transition between the uncracked and cracked stage.…”

Effect of fly ash addition on the fracture toughness of plain concrete at third model of fracture

“…The importance of the fracture toughness in the antiplane shear (Bazant et al 1990) is particularly visible in the analysis of structures subjected to torsion such as: slab, beams bent in the plan, end-beams in ceilings, balcony slab ring beams, girders of spatial frames, spiral stars, crane beams, T-beams and other. Selected examples of reinforced and prestressed concrete elements loaded in torsion were shown by Kamiński and Pawlak (2011) and Bernardo et al (2013). An analysis of reinforced concrete elements subjected to torsion is important especially in the state II of construction, i.e.…”