Numerical Simulation of Reinforced Concrete beam Under Flexure Using Finite Element Method

Understanding the response of concrete structural components such as beams, columns, walls during loading is indispensable for the development of safeand efficient structures. The present report deals with the non-linear static analysis of a Reinforced Concrete (RC) beam, having dimensions 4000mmX400mmX 250mm, with 4 nos. of 16mm diameter bar as main reinforcements, 8mm diameter at 200mm c/c as shear reinforcement, with two faces of the beam as fixed modeled and analyzed when subjected to two point loads at one-third span from each fixed support using the Finite Element Analysis software Ansys. The behavior of the analyzed beam has been observed in terms of flexural behavior, load-deflection responses, and crack pattern for various loading conditions until failure load. Keywords: Finite element analysis, ANSYS, flexural behavior, Reinforced Concrete (RC) beams, material non- linearity, shear reinforcement.

Experiment and Analysis of Mechanical Properties of Lightweight Concrete Prefabricated Building Structure Beams

Recent years have witnessed that the prefabricated concrete structure is in the widespread use of building structures. This structure, however, still has some weaknesses, such as excessive weight of components, high requirements for construction equipment, difficult alignment of nodes, and poor installation accuracy. In order to handle the problems mentioned above, the prefabricated component made of lightweight concrete is adopted. At the same time, this prefabricated component is beneficial to reducing the load of the building structure itself and improving the safety and economy of the building structure. Nevertheless, it is rarely found that the researches and applications of lightweight concrete for stressed members are conducted. In this context, this paper replaces ordinary coarse aggregate with lightweight ceramsite or foam based on the C60 concrete mix ratio so as to obtain a mix ratio of C40 lightweight concrete that meets the engineering standards. Besides, ceramsite concrete beams and foamed concrete beams are fabricated. Moreover, through three-point bending tests, this paper further explores the mechanical properties of lightweight concrete beams and plain concrete beams during normal use conditions. As demonstrated in the results, the mechanical properties of the foamed concrete beam are similar to those of the plain concrete beam. Compared to plain concrete beams, the density of foamed concrete beams was lower by 23.4%; moreover, the ductility and toughness of foamed concrete were higher by 13% and 3%, respectively. However, in comparison with the plain concrete beam, the mechanical properties of the ceramsite concrete beam have some differences, with relatively large dispersion and obvious brittle failure characteristics. Moreover, in consideration of the nonlinear deformation characteristics of reinforced concrete beams, the theoretical calculation value of beam deflection was given in this paper based on the assumption of flat section and the principle of virtual work. The theoretically calculated deflection values of ordinary concrete beams and foamed concrete beams are in good agreement with the experimental values under normal use conditions, verifying the rationality and effectiveness of the calculation method. The research results of this paper can be taken as a reference for similar engineering designs.

Deformation analysis of axially loaded weak PVC-fiber reinforced polymer confined concrete column-strong reinforced concrete beam joints reinforced with core steel tube

This paper presents an experimental study on 11 weak PVC-FRP Confined Concrete (PFCC) Column-strong Reinforced Concrete beam joints reinforced with Core Steel Tube (CST) subjected to axial load. The influences of the joint height, joint stirrup ratio, Carbon Fiber Reinforced Polymer (CFRP) strips spacing, steel ratio and CST length on the failure mode, ultimate strength, and strain behavior of specimens are analyzed and discussed. Test results indicate that the failure mode of specimens is distinguished by the cracking of PVC tube, fracture of CFRP strips, yielding of stirrups, and longitudinal steel bars in the PFCC columns. Both the longitudinal steel bars and CST yield at the joint area, while there is no obvious damage on the joint. The ultimate stress of specimens decreases with the increment of CFRP strips spacing, while the other studied variables have little impact on the ultimate stress. As the CFRP strips spacing increases, the ultimate strain of specimens decreases, and the strain development accelerates. Considering the effect of joint dimension, a modified prediction model for the stress–strain relationship of axially loaded weak PFCC column-strong RC beam joints reinforced with CST is proposed and verified with good accuracy.