Types Of Lateral Reinforcement Research Articles

A Feasibility Study on the Lateral Behavior of a 3D-Printed Column for Application in a Wind Turbine Tower

Although 3D printing technology has been applied worldwide, the problem of connecting a printed structure and a foundation has rarely been examined. In particular, loads in the horizontal direction, such as wind loads and earthquake loads, can significantly affect the stability of a printed structure. Therefore, in this study, the effect of lateral loads on printed columns that were connected to a foundation by two types of connectors was investigated. A steel angle with bolts and couplers was used to connect the printed column to a concrete footing. In addition, two types of lateral reinforcement were applied to the printed column to enhance its bonding strength and shear resistance. The lateral reinforcements were attached to the interface of the printed layers at distances of 100 and 200 mm to investigate the effect of lateral reinforcement distance on the lateral behavior of the printed column. The results showed that the use of couplers as connections between the columns and foundation significantly improved the load capacity. Furthermore, the effects of the lateral reinforcement types and lateral reinforcement distances were assessed.

Study of energy dissipation of reinforced concrete beam-column joint confined using varying types of lateral reinforcements

This study deals with the enhancement of energy dissipation of joints along with other characteristics using types of lateral reinforcement. The behavior of the joint is most critical under the seismic condition as it is most vulnerable when subjected to the lateral type of loads. The performance of joints decides the overall behavior of structure subjected to seismic loading. Hence, the study of the beam-column joint is important for developing a structure with better characteristics. A seven-storied reinforced concrete building inside the zone II is analyzed. One of the exterior beam-column joints at an intermediate storey is decided. Six one-third scaled exterior beam-column joint specimens are prepared with different types of lateral reinforcement and tested in the laboratory under reaction frame subjecting to cyclic and reverse cyclic loading. From an experimental study, it is observed that the energy dissipation capacity of the joint is increased along with the other different characteristics of the joint which enhance the behavior of the structure.

Behavior and Performance of GFRP Reinforced Concrete Columns with Various Types of Stirrups

Fiber reinforced polymer (FRP) composites are gaining acceptance in concrete structural applications due to their high ratio of strength/stiffness to self-weight and corrosion resistance. This study focused on the structural behavior and the performance of concrete columns internally reinforced with glass fiber reinforced plastic (GFRP) rebars. Twelve series of concrete columns with varied longitudinal reinforcement, cross section, concrete cover, and type of lateral reinforcement were tested under compression loading. The results show that the amount of GFRP longitudinal and lateral reinforcement slightly affects the column strength. The lateral reinforcement affects the confining pressure and inelastic deformation, and its contribution to the confined compressive strength increases with the GFRP reinforcement ratio. In addition, the confining pressure increases both concrete strength and deformability in the inelastic range. The confinement effectiveness coefficient varied from 3.0 to 7.0 with longitudinal reinforcement. The average deformability factors were 4.2 and 2.8 with spirals and ties, respectively. Lateral reinforcement had a more pronounced effect on deformability than on column strength.

Seismic Performance of Rectangular Hollow Bridge Columns

Seismic performance of rectangular hollow bridge columns is a significant issue for a high-speed rail project in Taiwan because ductility of these columns varies with the type of lateral reinforcement. In this paper two prototypes and four models of such columns were tested under a constant axial load and a pseudo-static, cyclically reversed horizontal load. Effects of ductility and dissipated energy are investigated. An analytical model is developed to predict the moment-curvature relationship of each section and the load-displacement relationship of the columns. Based on test results, seismic performance of the columns is presented. Test results are also compared to those from the proposed analytical model. Ductility factors of the tested specimens range from 3.45 to 11.1, and the analytical model satisfactorily predicts the load-displacement relationship of such columns with acceptable accuracy.

A model for the stress-strain relationship of rectangular confined normal and high strength concrete columns

In this paper an analytical model is developed to predict the complete stress-strain relationship of normal and high strength square and rectangular short columns confined with rectilinear hoops, cross ties, and combinations of different types of lateral reinforcement. The confinement pressure is assumed to be uniform within the core of the column. The internal force equilibrium, the properties of the materials, and the geometry of the section are used to evaluate the lateral pressures. The model utilizes a fractional equation which gives a realistic description of the behaviour of the confined sections. Comparisons are made between the predictions of the model and the available experimental results. The model demonstrates good predictive capability for a variety of cross-sectional shapes and configurations of longitudinal as well as lateral confinement reinforcement. The effects of different parameters, such as the concrete strength, the amount of confining steel, and the configurations of the longitudinal as well as lateral reinforcement, on the behaviour of the confined columns are presented and discussed.

Strength and Ductility of Confined Concrete

An analytical model is proposed to construct a stress‐strain relationship for confined concrete. The model consists of a parabolic ascending branch, followed by a linear descending segment. It is based on calculation of lateral confinement pressure generated by circular and rectilinear reinforcement, and the resulting improvements in strength and ductility of confined concrete. A large volume of test data, including poorly confined and well‐confined concrete was evaluated to establish the parameters of the analytical model. Confined concrete strength and corresponding strain are expressed in terms of equivalent uniform confinement pressure provided by the reinforcement cage. The equivalent uniform pressure is obtained from average lateral pressure computed from sectional and material properties. Confinement by a combination of different types of lateral reinforcement is evaluated through superposition of individual confinement effects. The descending branch is constructed by defining the strain corresponding to 85% of the peak stress. This strain level is expressed in terms of confinement parameters. A constant residual strength is assumed beyond the descending branch, at 20% strength level. The model is compared against a large number of column tests. Circular, square, and rectangular columns, with spiral and rectilinear reinforcements, as well as welded wire fabric, are used for comparison. Comparisons include concentric and eccentric loadings, as well as slow and fast strain rates. The results indicate good agreement.

Confinement of Prestressed Concrete Columns

P restressed concrete columns have several advantages over columns reinforced with deformed reinforcing bars as the main vertical reinforcement. Besides being economical to construct and transport, prestressed columns make use of both concrete and steel more efficiently and require a smaller amount of longitudinal reinforcement. The precompression of concrete provides additional resistance to tensile stresses encountered during transportation and erection stages, and protects against accidental loads resulting from small eccentricities, Prestressed columns also have the added structural advantage of maintaining a higher uncracked stiffness longer to resist axial and transverse loads. Numerous investigations 14 have been carried out in the past to evaluate the effects of eccentricity, level of prestress, slenderness, and material properties on the strength of prestressed columns. In most of these and other similar studies, the effect of different types of lateral reinforcement on strength and ductility of prestressed columns was seldom a variable in the investigation. Considerable test data are available on the effect of lateral reinforcement on the ductility of nonprestressed columns, but similar information on prestressed columns is severely lacking. As indicated by the test results reported herein, the conclusions derived concerning lateral reinforcement from tests on nonprestressed columns may not be directly applicable to prestressed columns. Lateral reinforcement in prestressed columns is typically provided in the form of individual closed ties, the fabrication and placement of which can be quite labor intensive. The use of a continuous square spiral as lateral reinforcement has proven economical in precast piles and holds a similar promise in prestressed columns. Welded wire fabric is another type of reinforcement which, because of its economy in fabrication and placement, could possibly be used as lateral reinforcement in pre-