Precast Concrete Columns Research Articles

Quasi-Full-Scale Experimental Study on Bridge Precast Concrete Columns under Static Loading

Abstract Precast concrete columns have been widely used in bridge constructions. Most studies regarding precast columns focused on seismic instead of static behaviors. To investigate the cracking m...

Structural Performance of PC Double Beam\u2013Column Connection Under Gravity and Seismic Loading

Recently, as a new precast concrete (PC) construction method for increasing economy and constructability, the PC double-beam system has been developed for factories or logistic centers, where construction duration is particularly important. In this study, half-scaled PC double beam–column connection was tested under gravity loading and cyclic lateral loading. The major test parameters included the use of the spliced PC column and the addition of reinforcement at the beam–column joint. In the gravity loading test, the flexural behavior of the PC double beam was investigated. The test results showed satisfactory flexural capacity at the PC double-beam section, validating the composite action between the PC and RC members. In the cyclic lateral loading test, the seismic performance of the PC double beam–column connection was investigated. Based on the test results, the failure mode, load-carrying capacity, deformation capacity, energy dissipation capacity, secant stiffness, and shear strength of the PC double-beam system were evaluated and compared with those of a conventional RC double beam–column connection. According to the test results, the structural performance of the PC double beam–column connection was comparable to that of the RC double beam–column connection and satisfied the acceptance criteria of moment frame in the ACI 374.1-05 provision.

Post-fire seismic performance of precast reinforced concrete columns

Quantifying the seismic resistance of reinforced concrete buildings after fire is difficult because of the lack of information regarding their strength and ductility under earthquake loads. In this study, four full-scale flexure-controlled reinforced precast concrete columns were subjected to quasi-static reversed cyclic lateral loading under constant axial load to examine the seismic response of reinforced precast concrete columns damaged by 30, 60, and 90 minutes of fire. For the first time, the impact of fire damage on force-displacement behavior, moment-curvature relationship, stiffness, energy dissipation capacity, and residual displacements was investigated through postfire seismic tests. Test results clearly indicated that the fire exposure did not significantly affect the lateral-load-bearing capacity, failure modes, and ductility of the columns, with the exception of the specimen subjected to 90 minutes of fire exposure. The analytical study consisting of thermal and fiber-based structural analysis demonstrated that conventional principles of structural mechanics are valid for estimation of the postfire seismic behavior of reinforced precast concrete columns when the deteriorations in materials are realistically taken into account and the given algorithm is followed.

Probabilistic seismic vulnerability and loss assessment of a seismic resistance bridge system with post-tensioning precast segmental ultra-high performance concrete bridge columns

Precast segmental ultra-high performance concrete (UHPC) columns with post-tensioned (PT) tendons can effectively protect the compression toe from damage and enhance energy dissipation (ED) capacity of column compared to conventional segmental concrete columns. Extensive experiments and numerical studies have been carried out to explore the cyclic response of segmental UHPC columns in the existing literature; however, the effect of such novel columns on the seismic safety of bridge structures has not been thoroughly understood. This study aims to numerically assess the seismic fragility and seismic life-cycle loss of bridge structures supported by the precast segmental UHPC columns. For comparison, the seismic performance of the same bridge with monolithic reinforced concrete (RC) piers are also evaluated. Here, three-dimensional (3D) numerical models are generated to simulate these two bridge types. A performance-based earthquake engineering (PBEE) framework is used to evaluate and compare their seismic performance. The segmental UHPC column model is validated with the previous experimental studies. The validated model is combined into the whole bridge. Numerical results showed that the precast segmental UHPC bridge experiences similar peak acceleration and larger peak displacement in comparison to the monolithic RC bridge. The segmental UHPC bridge pier experiencing lower residual deformation can effectively reduce the damage probability and life-cycle loss of a bridge compared to the conventional monolithic RC pier. Under the design event (2475-year return period) and maximum considered event (5000-year return period), the expected losses of the segmental bridge in the lifetime were approximate 92% and 84% of that of the monolithic bridge, respectively. The segmental UHPC bridge has a noticeable economic benefit when such a bridge is constructed in regions of high seismicity.

Experimental study on seismic performance of precast segmental concrete columns after seawater freeze-thaw cycles

To accelerate construction speed, precast segmental concrete bridge columns are widely used in offshore bridge construction. Due to the cyclic action of the tide and the difference of temperature between seawater and atmosphere, offshore piers inevitably experience seawater freeze–thaw cycles in cold climates. The purpose of this paper is to study the seismic performance of precast segmental concrete columns after seawater freeze–thaw cycles through experimentation. Based on the low cyclic loading test on 12 specimens with different freeze–thaw cycles, stirrup spacing values, axial compression ratios, and longitudinal reinforcement diameters, the seismic performance of precast segmental concrete columns was evaluated through analyzing cracking and failure patterns, hysteresis characteristics, skeleton curves, stiffness degeneration, and energy dissipation capacity. The experimental results reveal that, for the specimens with the same design parameters, increasing the number of freeze–thaw cycles from 0 to 125 gradually reduces the peak value of the lateral load, the initial stiffness, and the cumulative energy dissipation but continuously increases the peak displacement. Moreover, for the specimens experiencing 125 freeze–thaw cycles, longitudinal reinforcement diameter, axial compression ratio, and stirrup spacing are the main factors affecting the seismic performance of precast segmental concrete columns.

Experimental and numerical study of precast concrete columns with hybrid bolted splice connections

The seismic performance of precast concrete (PC) columns using bolted splice connections was investigated, where the connection was composed of column shoes, bolts and grout. In order to ensure satisfactory seismic performance the PC columns were joined in the middle part of the columns where the bending moment is reduced. A total of six specimens were constructed and tested with varying axial load ratios. One specimen was cast-in-place (CIP), one specimen was assembled with the hybrid connection positioned at the column base where the moment is greatest, and the remainder were assembled with the hybrid connection positioned in the central portion of the storey height. Damage states, load-carrying capacity, ductility and energy dissipation of the specimens was studied and compared. In addition, fiber element modelling was validated and implemented in order to investigate the effect of connection location. Findings from the experimental and numerical simulations indicated that the PC columns that contained the hybrid connection located in the central portion of the storey height with corresponding reduced bending moments exhibited simulated seismic performance that was comparable to the response of CIP columns.

Concrete prestressed poles in the high voltage lines

In the paper the structure of Polish post-tensioned concrete poles used in 1950s and 60s for construction of overhead power lines of 110 kV voltage was described. Short description of precast concrete columns and their foundations are given with respect to technical solutions and durability. The conclusions drawn from long-term exploitation and maintenance were given on the basis of actual and contemporary Codes of Practice. On the background of these solutions modern post-tensioned spun concrete poles were presented as attractive alternative in terms of their economical efficiency.

Effect of Major Design Parameters on the Seismic Performance of Bridges with Hybrid Sliding–Rocking Columns

This paper explores the effects of major design variables on the seismic performance of the so-called hybrid sliding–rocking (HSR) bridge columns. The HSR bridge columns are precast concrete segmental columns with internal unbonded posttensioning, end rocking joints and intermediate sliding joints, which offer significant self-centering and energy dissipation capabilities. HSR columns introduce additional design variables, the effects of which on the seismic response of such columns have remained unclear. Using a recently developed robust computational modeling approach, this study identifies four major design variables, investigates their effects on the dynamic response of HSR columns, and proposes component-level design recommendations. The four design variables include the number of the sliding joints and their distribution over the column height, the incipient sliding base shear, the incipient bearing sliding amplitude, and the peak achievable sliding capacity. This study further investigates the effect of the vertical component of the earthquake excitation on the response of HSR columns and compares the seismic performance of an HSR column with that of a rocking-only column of the same strength. The findings indicate that HSR columns can be more damage resistant than rocking-only columns under earthquake excitations. The response of HSR columns was found to be insensitive to the vertical component of the earthquake excitation.

Experimental study on seismic performance of an improved precast reinforced concrete column-to-column joint

The seismic performance of an improved column-to-column connection in the precast concrete frame is studied in this article, including five precast specimens and one cast-in-place specimen. The traditional reinforced concrete tenon connection of precast concrete frame columns is replaced by the concrete-filled steel tubular tenon. The welding or cold extrusion sleeve connection of the column longitudinal bars is replaced by rolling straight thread sleeve connection. The six-frame column specimens were fabricated and tested subjected to low-reversed cyclic loading. Efforts have been made to study the characteristics of an improved tenon column joints, such as the failure mode, the hysteretic curves, the skeleton curves, the stiffness degradation, the ductility, and the energy dissipation. The test results show that the seismic performance of the precast columns with the suggested tenon connection is similar to that of the cast-in-place columns.

Stress Wave Propagation and Structural Response of Precast Concrete Segmental Columns under Simulated Blast Loads

Although a number of precast concrete segmental columns (PCSC) have been built and developed in recent years owing to their various advantages, the dynamic responses of the column under blast loads are not well investigated. The characteristics of stress wave propagation within the column and their effects on the response and failure of the PCSC are still unknown. Understanding blast load induced stress wave propagation and the subsequent dynamic structural responses of PCSC is essential for blast resistant design and protection of PCSC. In this study the dynamic behaviours of the PCSC under blast loads are numerically investigated by using the explicit finite element software LS-DYNA. The numerical models and modelling techniques are carefully validated by three experimental blast tests from three different studies. The stress wave propagation within the cross-section and along the column height caused by blast loads is examined. The effect of steel tubes in protecting the PCSC from the blast loads is also investigated. It is found that the deformation of the column section under blast loads consists of two main phases, i.e. compression phase and expansion phase, in which failure of the concrete segment mostly occurs in the latter phase. Besides, the use of steel tubes has a marginal influence during the compression phase on the concrete section, but it becomes crucial in the expansion phase that the local failure of concrete segment, i.e. spalling and scabbing, is prevented by the confining effect. Furthermore, confining all concrete segments by steel tubes shifts the response of the PCSC from the local failure of the concrete segment to the global flexural response with fracture of the post-tensioned tendon. The influence of the blast location on the response of the column is also investigated in this study.

Experimental investigation on seismic performance of mechanical joints with bolted flange plate for precast concrete column

The conventional assembled monolithic grouted sleeve connection of column–column joints continues to require in situ grouting, which has certain disadvantages, including the necessity of wet construction. Compared with cast-in-situ columns, its seismic performance is relatively insufficient in terms of deformation and energy dissipation capacity. In this paper, a new type of precast concrete column–column joint and its corresponding column base joint with a steel jacket for confining the concrete core and bolted flange plate is proposed to achieve rapid erection. Six specimens are tested at a high axial compression ratio and cyclic reversed loading, including three precast column–column joints with bolted flange plate, one column base joint with bolted flange plate, one grouted sleeve connection joint, and one cast-in-situ column. This study focuses on the effects of the ratio of longitudinal reinforcement to the gap between the steel jacket and upper concrete on seismic performances. Test results indicate that this new joint is reliable, and all failure modes involve the flexural failure of the precast upper column. The influence of tensile reinforcement on the out-of-plane deformation of the flange plate is minimal. Compared to the cast-in-situ column, the column with a flange plate connection has a more gradual crack development, a slightly higher resistance, an improved ductility, and a better energy dissipation capacity. With the increase in longitudinal reinforcement ratio, the confining effect of the steel jacket on the concrete core becomes more distinct. The gap between the steel jacket and upper concrete could effectively delay the compressive damage on the concrete surface. Finally, considering the confining effect of the steel jacket, the flexural capacity of the proposed precast column is determined using the fiber model. The predicted results approximate the test values and are all within the safe range.

Experimental study on precast beam-column connections with continuity reinforcement for negative bending moments

Abstract In this paper, an experimental investigation is presented on semi-rigid interior beam-to-column connections constituted by precast concrete beams supported on precast concrete column corbels and bending continuity reinforcement bars for bending negative moments. The main purpose of this paper was to analyze the influence of vertical interface grout filling between the corbel and the beam and the position of the bending continuity reinforcement bars (crossing only the column or crossing only the slab) on the behavior of this type of connection. Tests on eight specimens were performed. It was noticed that the vertical interface grout filling contributed to increase both rotational flexural stiffness and flexural strength capacity of the connections when compared to the connections without grout filling. It was also noticed that in the specimens in which the continuity bars crossed only the column, the rotational flexural stiffness was higher. For these last ones, coefficients k and β for predicting the secant stiffness by simplified expression present in Brazilian Code NBR 9062 were evaluate from experimental results. These evaluated coefficients may be regarded as indicative values for structural designers and helpful for future researches.

Cost reduction effects of in-situ PC production for heavily loaded long-span buildings

ABSTRACTThe precast concrete (PC) method is preferable in construction activities for its short construction time, guaranteed quality, and cost-effectiveness. Most researchers and engineers believe that these benefits are maximized if the PC components are produced at manufacturing plants. However, under similar production conditions, the in-situ production of PC components can save production costs while providing quality equal to or better than in-plant production. Several studies have described the benefits for the cost reduction effects of in-situ production. However, the verification by using case studies was not conducted. The purpose of this study is to analyze the cost reduction effects of the in-situ production of PC elements. For this study, a case project was selected to establish an in-situ production plan and PC columns were produced on site. Then, the cost reduction effects were analyzed using the actual data of the case project. The results of this study will be used as a core for the development of algorithms for in-situ production of PC components.

Seismic Performance of a New Type Concrete-Filled Precast Concrete Tubular Column

To investigate the seismic behaviour of a new type of concrete-filled precast concrete tubular column, five concrete-filled precast concrete tubular columns varying in concrete strength and stirrup ratio were tested under cyclic loading. The behaviours of the failure mode, hysteretic curve, skeleton curve, bearing capacity, deformability, displacement ductility and energy dissipation were studied to evaluate the seismic resistance performance of the columns. The results show that the failure mode of the concrete-filled precast concrete tubular columns was flexural failure, and the hysteretic curve had a plump shuttle shape, which indicates that the concrete-filled precast concrete tubular column has good energy dissipating capacity. The bearing capacity of the specimen was increased with increasing concrete strength of the precast tube. The stirrup ratio has little effect on its bearing capacity, whereas it has a significant effect on the deformation, ductility and energy dissipation. The story drift of the specimens can meet the requirements of the elastic plastic story drift limit value of 1/50 of the code in China, and the ductility coefficient is greater than 3, which demonstrates that the concrete-filled precast concrete tubular column has excellent seismic properties.

Experimental study on fire resistance of precast concrete columns with efficient reinforcement

In order to improve installation efficiency, construction quality and reduce the cost of monolithic precast concrete frame structures, precast concrete columns reinforced by efficient reinforcement have been proposed in recent years. Their static and seismic behaviors generally meet design expectations, while, to the authors’ best knowledge, their fire resistance has not been properly studied. In this paper, results from fire resistance experiments on full-scale precast concrete columns reinforced by efficient reinforcement under standard fire exposure conditions are presented. The effect of reinforcement forms, load intensity and fire conditions on the fire resistance of the precast concrete columns has been studied. The test results show that fire resistance of the connection zone of the precast concrete column is higher than that of the non-connection zone. The test results also show that precast concrete columns reinforced by cluster reinforcement have a higher fire resistance than columns reinforced by large-diameter reinforcement. On the basis of the test results and the calculation methods current in use, a simplified approach that considers the effect of cross-sectional area reduction and temperature difference caused by spalling is proposed to predict fire resistance of precast concrete columns reinforced by efficient reinforcement.

Seismic Performance of Precast Concrete Columns with Improved U-type Reinforcement Ferrule Connections

This paper proposes a new kind of U-type reinforcement ferrule (URF) connection for the assembly of precast concrete (PC) components, which has a good fault-tolerance ability and low cost of construction with a simple post-grouting process. The modified connection features welded U ferrules, which can increase the bonding mechanism and internal stress transmission in the spliced region. A series of quasi-static cyclic tests were performed on URF-connected PC columns with different welding patterns. Comprehensive comparisons were performed on the load-bearing capacity, the plastic energy dissipation ability, the internal force transmission, the column ductility and the stiffness. The results indicated that PC columns with welded URF connections can ensure better lateral resistance than the cast-in-place concrete column. The weld type and length influence the connection performance, and the 15d-welded and full-length welded URF connections presented better connection performance and were suggested for the assembly of PC columns. Then, finite element analyses were performed to further reveal the working and failure mechanisms and the affecting mechanism of some working parameters. Parametric simulations indicated that the increase in the axial load ratio and the concrete strength in the postcast region had a slight but limited effect on improving the lateral resistance of the column connection.

Experimental Investigations on the Seismic Behavior of Precast Concrete Columns with Novel Box Connections

In this study, two types of novel box connections were developed to connect precast concrete (PC) columns and to ensure load transfer integrity. Cyclic loading tests were conducted to investigate the seismic behavior of the PC columns with proposed connections as well as the feasibility and reliability of novel box connections. The failure mode, hysteretic behavior, bearing capacity, ductility, stiffness degradation and energy dissipation were obtained and discussed. The test results indicated that the all PC columns exhibited the ductile flexural failure mode and that the proposed connections could transfer the force effectively. The adoption of novel box connections could improve the deformation capacity and energy dissipation capacity of PC columns. A higher axial compression ratio could enhance the bearing capacity of PC column with proposed connection but would significantly deteriorate the ductility and energy dissipation capacity. Finite element models were developed and the feasibility of the models was verified by the comparison with the test results.

Erratum for “Experimental and Nonlinear Numerical Analysis of Precast Concrete Column Splices with High-Yield Metal Plates” by J. D. Nzabonimpa and Won-Kee Hong

Erratum for “Experimental and Nonlinear Numerical Analysis of Precast Concrete Column Splices with High-Yield Metal Plates” by J. D. Nzabonimpa and Won-Kee Hong

Seismic behavior of normal-strength concrete-filled precast high-strength concrete centrifugal tube columns

This study reports the cyclic loading test results of normal-strength concrete-filled precast high-strength concrete centrifugal tube columns. Seven half-scale column specimens were tested under cyclic loads and axial compression loads to investigate their seismic behavior. The major parameters considered in the test included axial compression ratio, filled concrete strength, and volumetric stirrup ratio. The structural behavior of each specimen was investigated in terms of failure modes, hysteresis behavior, bearing capacity, dissipated energy, ductility, stiffness degradation, drift capacity, and strain profiles. Test results revealed that the concrete-filled precast high-strength concrete centrifugal tube column exhibited good integral behavior, and the failure modes of all columns were ductile flexural failures. Lower axial compression ratio and higher volumetric stirrup ratio resulted in more satisfactory ductile performance. In contrast, the filled concrete strength has a limited influence on the structural behavior of concrete-filled precast high-strength concrete centrifugal tube columns. Based on the limit analysis method, the calculation formula for the bending capacity of the concrete-filled precast high-strength concrete centrifugal tube column was developed, and the results predicted from the formulas were in good agreement with the experiment results.

Experimental study on the seismic behavior of precast concrete column with grouted corrugated sleeves and debonded longitudinal reinforcements

The seismic performance and the influence of debonded longitudinal reinforcements at the footing on the precast concrete columns connected with the embedded grouted corrugated sleeve were investigated experimentally in this research. Low cyclic loading tests were carried out on eight bending columns and four shear columns, considering the designed parameters of the partial debonding of the longitudinal reinforcements above the column–foundation interface, the axial load index, and the strength of the stirrups. Experimental results indicate that the partial debonding of the longitudinal reinforcements heavily influenced the damage spreading of the bending columns, but does not affect the damages of the shear columns. Compared to the columns without debonded longitudinal reinforcements, the seismic behaviors in terms of the ductility and energy dissipation can be improved clearly by the partial debonding of the longitudinal reinforcements for bending columns, but there was no clear improvement for shear columns. In addition, with the decrease of the axial load index or the increase of the strength of the stirrups, the seismic behaviors of the precast columns with the partial debonding of the longitudinal reinforcements are improved largely.