Precast Concrete Girders Research Articles

Data-driven study on shear bearing capacity of segmental concrete joints

Segmental assembly joints with excellent shear bearing capacity are the key to ensure the integrity of precast concrete girder bridges, which directly affects the force transmission state of the girders. However, with the existence of unfavorable factors such as the multi-key shear capacity reduction effect, the traditional prediction model for calculating the concrete joints shear capacity has poor prediction accuracy and large dispersion. To overcome the shortcomings of the existing prediction model, this study established a database consisting of 311 sets of test data and 110 sets of numerical results based on existing research. A total of seven data-driven models for predicting shear capacity of concrete joints were trained and generated based on the database, namely, two linear models (Linear Regression Support Vector Machine Algorithm, Least Squares Linear Regression) and five nonlinear models (Neural Network Bayesian Regularization; Neural Network Quantized Conjugate Gradient Model, Neural Network Levenberg-Marquardt (LM), Decision Tree, and Gaussian regression). The coefficient of determination (R2), root mean square error (RMSE)，mean absolute error (MAE), error range (A20-index), and error analysis were adopted to evaluate those model's performance. The evaluation results show that the LM model has excellent prediction accuracy, stability, robustness, and can guide the engineering design. Finally, the established database (421 data sets) and trained LM algorithm model were open sourse in this study to promot the investigate of precast concrete structures.

A Numerical Investigation of Longitudinal Track–Bridge Interaction in Simply Supported Precast Concrete Girder Railway Bridges

A Numerical Investigation of Longitudinal Track–Bridge Interaction in Simply Supported Precast Concrete Girder Railway Bridges

Investigation of Failures of Three Precast Post-Tensioned Segmental Concrete (PSC) Box Girder Bridges During Construction

Considering the fast pace of construction development, with a consistent increase in the volume of traffic, both road and rail traffic in developing countries like India, which are constrained by the limitation of land availability, especially in built-up or urban areas, lateral expansion in transport facilities has become increasingly challenging. Under such circumstances, vertical expansion through the construction of long flyovers or elevated structures is the most viable solution to meet traffic demand. Road and railway bridges are complex structures by nature with respect to their design and construction requirements based on a high level of knowledge, expertise and experience. Hence, some structural failures are taking place even during the construction stage of bridges owing to material quality issues as well as human error, to name but a few of the causes. This paper presents three case studies related to the investigation process and the primary cause(s) of the collapse of three different precast concrete post-tensioned segmental concrete (PSC) box girder bridges in India, with the corresponding lessons learnt and proposed recommendations. This paper covers issues relating to the investigation of the reasons leading to the failures of three precast concrete PSC box girders and a few suggestions for remedial measures.

Pullout test for PC column-capital grouted rebar connection with corrugated duct

Double-beam precast concrete (PC) structures require large capitals to support a wide PC girder. In this study, a segmented PC column-capital system is developed to overcome the disadvantages of conventional PC columns in terms of manufacturing, transportation, and construction. In the proposed segmented PC column-capital system, large PC capitals are assembled with PC columns using the proposed corrugated rebar connections filled with grouted mortar. To verify the load-transfer capacity of the proposed corrugated rebar connections, pullout load tests are conducted under various test parameters, including the mortar compressive strength, curing time, bond length, and embedment length. To enable rapid construction, a relatively short curing time of 1–2 days is addressed. The test results indicate that the pullout performance of the proposed corrugated rebar connection is primarily affected by the mortar compressive strength fm’ and embedment length ld. When fm’ > 7.9 MPa and ld = 800 mm, the proposed corrugated rebar connection transfers tensile loads corresponding to construction loads. When fm’ > 21.0 MPa and ld = 800 mm, the proposed rebar connection can resist the tensile yielding load of the connected vertical rebar even after one-day of curing. However, when ld is less than 800 mm, bond-slip failure occurs because of the insufficient bond length. Based on the test results, a parametric analysis is conducted using a finite-element model. Similar to the experimental result, the numerical result shows that the bond strength of the proposed rebar connections is significantly affected by fm’ and ld. Hence, a bond-strength model of less-hardened grouted mortar with a bond stress of τb = 0.20 fm’ is suggested based on the previous and present test results as well as parametric analysis results.

Dynamical analysis of a 40 m span precast posttensioned concrete girder during lifting operations

AbstractCranes are employed to lift precast concrete girders during their construction. Presently, there is no recommendation for operational velocities during girder assemblage, particularly for long elements; simultaneously, several accidents have been reported during the transitory phase of girder motion. Since this mechanical problem has been examined in technical literature using a static approach, the present research study aims to investigate the dynamical behavior of a long, prestressed concrete girder by determining critical operational velocities according to crane movements. Prestressing cables' eccentricity and lifting loop position deviation were accounted for in 3D finite element simulations of a 40 m span precast prestressed concrete girder. Transient nonlinear analyses to obtain stresses and deflections were performed, so as to account for the large deformation behavior of the motion. A frequency domain approach was employed to analyze the time history results using the girder's natural frequencies obtained by modal analysis. The finite element model was developed to simulate upward, downward, and lateral girder movements. The most significant displacements and stresses were observed in the highest girder acceleration peaks, amplified by eccentricities. Safety against cracking and subsequent failure during vertical and lateral movements was ensured for crane operating accelerations of 0.02 g (v = 20 cm/s) and 0.007 g (v = 7 cm/s), respectively. Compared with the usual static analysis, for the critical case investigated, the inertial effect intensified the tensile stresses by 27 times, increased the compressive stresses by 11%, and increased the girder deflection by 3 times.

Grillage Analysis of Prestressed Concrete Girder Deck Superstructure for NH-16 Bridge Flyover; Part-1

Abstract: The bridge superstructure flyover built on National Highway route 16 (NH-16) near Benz circle in Vijayawada to act as grade separated highway for vehicles to cross over National Highway route 65 (NH-65) is made of precast and post-tensioned concrete girders. This article is the first part of the two phase study that focuses on the structural analyses of concrete bridge girders. The bridge girders are analyzed for vehicular loads considered as per Indian Roads Congress Specifications. The IRC Class of loads of 70R and Class A and their wheel load configurations are discussed. The bridge girders along with deck are modeled as grillage girder-slab members in Staad Pro analysis software. The bending moments and shear forces are computed for each of the IRC vehicular load configurations and the envelope forces for governing load configuration are presented for each of the girders. Finally, the article summarizes the maximum flexural and shear demands on the bridge girders. The pros and cons of grillage analysis modeling for prestressed girders and the alternate superior options for precise but quick modeling are also recommended.

Shear resistance mechanism of prefabricated large-scale gerber girder

In this study, shear tests were conducted to investigate the shear resistance mechanisms of Gerber precast concrete (GPC) girders consisting of PC end units, PC girder units, and cast-in-place concrete. To this end, individual PC end-member and mid-girder specimens were fabricated along with five GPC girder specimen with CIP concrete. The key test variables were overlapping (hanging) length and connection details of the mid-girder and end units. The test results showed that the shear performance of the composite GPC girder was significantly influenced by the connection details of the end-member and mid-girder. In the specimen where the mid-girder was simply assembled with the end-member without bolts, the failure was dominated by the damage concentrated on the bottom flange of the end-member. In contrast, in the specimen with the end-member and mid-girder assembled with bolts, there was no significant damage to the connection region, resulting in exerting full shear capacity. Additionally, based on the load–displacement response, crack pattern, and strain behavior measured from the experiment, the load-transfer mechanism of the GPC girder was estimated and reflected to propose a strut-and-tie model (STM) for the shear design of the GPC girder. The proposed STM was found to evaluate the shear strengths of the GPC girder specimens with a higher degree of accuracy than the shear strength evaluation method based on design code equations. Therefore, tied-arch mechanism can be assumed to dominate the main shear transfer mechanism when designing the GPC girder.

Measurements of rotational stiffness for precast concrete girder transport vehicles, part 2

This paper presents field measurements of the rotational stiffness of three transport vehicles equipped with different types of suspensions: leaf, combined air and leaf, and hydraulic suspensions. The rotational stiffness was determined by measuring the tilts of the vehicles when a girder or known weights were placed on them at various eccentricities. One of the tested vehicles, which featured transversely expandable wheel spacings varying from 6 to 18 ft (1.8 to 5.5 m), exhibited an increase in rotational stiffness from 78,181 to 134,584 kip-in./radian (8833 to 15,206 kN-m/radian). This paper summarizes the rotational stiffness for all the vehicles tested by the authors. The field measurements conducted have enriched the existing database on vehicle rotational stiffness in the United States.

Measurements of rotational stiffness for precast concrete girder transport vehicles—part I

Long precast, prestressed concrete girders are becom¬ing popular in bridge construction. Several states have constructed bridges using slender I-girders that exceed¬ed 200 ft (61 m) in length. When such a girder is seated on flexible supports such as a jeep and dolly, it can roll about an axis located beneath its center of mass. This movement induces lateral bending, which raises concerns about the lateral stability of particularly long girders. While the stability of these girders is largely influenced by the hauling equipment, very few state transportation agencies offer guidelines addressing the rotational stiffness of transport vehicles and other critical parameters. This paper presents comprehensive field measurements of rotational stiffness from various precast concrete plants. It covers two methods— namely, the placement of eccentric loads and the parking of vehicles on a substantial cross slope—to gauge rotational stiffness. The measurements included a variety of transport vehicles with air and leaf suspensions. The examined vehicles displayed a rotational stiffness ranging from 22,000 to 42,000 kip-in. (2486 to 4745 kN-m) per radian. The paper also suggests a guideline for tilt measurements to gather essential data and pinpoint the rotational stiffness.

Considerations for Precast Concrete Girder End Regions with Large-Diameter Strands

Considerations for Precast Concrete Girder End Regions with Large-Diameter Strands

The Risk of Failure Assessment in Bina Marga Standard Designed Prestressed Concrete Girder Bridges under B-WIM Load Measurement

The use of precast prestressed concrete girder bridges in Indonesia has been increasing rapidly due to their high quality, reliability, and faster construction on site. The girder components are typically designed for a specific bridge span and can be prefabricated. The Directorate General of Highways of the Ministry of PUPR (Bina Marga) has released a standard design for prestressed concrete girder bridges with a typical span of up to 40 m. This design is based on the bridge loading standard SNI 1725 2016, which determines the live traffic load through consensus due to limited data on actual traffic load measurement results. However, the Ministry of PUPR has been implementing actual traffic load measurements using weigh-in-motion (WIM) technology to directly measure the load of passing vehicles. In this study, a risk assessment of the failure risk of a standard Bina Marga bridge with a 40-m span prestressed concrete girder type was conducted based on B-WIM load measurements. The results of this assessment indicate that the standard Bina Marga bridge has a failure risk of 1.48 x 10-4, which is smaller than the acceptable risk of failure according to the AASHTO LRFD Bridge Design Specification as referenced in SNI 1725 2016.

Investigation of interface shear transfer in engineered cementitious composite members

ABSTRACT Interface shear transfer (IST) is critical for achieving composite behavior at the connection between precast concrete girders and cast-in-place decks. In this study, an experimental program was conducted to evaluate the IST behavior when concrete members are constructed using engineered cementitious composites (ECC) compared to conventional concrete (NC). Variables considered in the experimental program included concrete type, interface roughness and interface reinforcement. The specimens, with the ECC-to-NC layer combination, roughened interface and no interface reinforcement, showed 50% and 90% of IST strength and stiffness, respectively, compared to those of conventional IST specimen with NC-to-NC layer combination, roughened interface and 2#3 interface reinforcement. Additionally, the conventional IST layer combination (NC-to-NC with two interface reinforcement and roughened interface) showed the same level of IST strength compared to the layer combination of ECC-to-NC with the same interface reinforcement and interface roughness.

Flexural performance of T-shape light-weight concrete filled steel tubular girder

This paper proposes an optimization study for both structure and materials to obtain an affordable, long-span, light-weight, and fast-constructing T-shape lightweight concrete-filled steel tubular (LWCFST) girder in order to be used in bridge construction. This research was performed on a hollow steel tube of Steel-52 (yield limit 360 MPa), which was filled with LWC. A set of parameters had been investigated to illustrate its effect on T-shape LWCFST girder stiffness, toughness, resilience, and ultimate carrying load capacity in order to obtain an equivalent stiffness to that of the typically used precast concrete girder. Based on design codes (EN 1994-1-1/Euro code 4 and ANSI/AISC 360-10) that permit the use of LWC as a filler material, the parameters considered were: the thickness of the steel tube, compressive strength of the filler concrete, and the bond condition between the steel tube and filler lightweight concrete. The yielding and ultimate bending capacity were determined based on the interpreted failure criteria of T-shape LWCFST girder, considering non-linear analysis for both material and loads using ANSYSWORKBENCH software. The results showed that T-shape LWCFST girder can be employed as a significant relative economic alternative to a typical precast girder in the bridge construction field, thanks to its high stiffness/weight ratio. The lightweight concrete inside was effectively employed to delay the local web buckling of the steel tube to increase its bending capacity. In addition, it reduced the total self-weight of the bridge’s superstructure by 20% compared with a typical precast concrete girder. The dominant failure of T-shape LWCFST girders was found in the upper concrete slab due to the compression stress, even though the tensile cracks in the filler concrete occurred after reaching tensile yield stress in the steel tube. Additionally, increasing the value of friction coefficient between steel tube and lightweight concrete up to 0.8 was found to significantly affect the girder stiffness and has a slight effect after, no matter how high it is.

Experimental and Analytical Study on the Shear Transfer in Composite Post Tensioned Precast Concrete Girders

Experimental and Analytical Study on the Shear Transfer in Composite Post Tensioned Precast Concrete Girders

Field Performance of High-Early-Strength Concrete with Polypropylene Fibers as a Cost-Effective Alternative for Longitudinal Connection between Bridge Deck Bulb-T Girders

High-early-strength (HES) concrete with polypropylene fibers has been used in several parts of bridges with precast concrete girders by the Idaho Transportation Department (ITD). This material is only slightly more expensive than conventional concrete, but speeds up the construction. ITD is interested in the suitability of HES concrete in the longitudinal closure pour connections between bridge deck bulb-T girders. In the laboratory phase of this project, an optimum HES concrete mix was identified through a series of laboratory experiments. The field performance of the HES concrete mix was examined by placing the material in the closure pour joints between deck bulb-T girders in a bridge in Idaho. The main focus of this paper is to report on the 20-month field performance of the bridge closure pour concrete. Tasks included six visits to the bridge site every 4 months to (1) measure strain data under ITD’s Under the Bridge Inspection Truck (UBIT), (2) measure strain data under commercial truck traffic, and (3) inspect the closure pour concrete. Based on the results, it was concluded that there were no changes in the closure pour concrete in the last 20 months.

Investigating UHPC in deck bulb-tee girder connections, part 2: Full-scale experimental testing

Deck bulb-tee girders constitute an excellent precast concrete bridge element system for medium- to longspan bridges. The precast concrete girders are transported to the jobsite, where they are placed adjacent to each other. The girders are connected using field-cast longitudinal joints. When required, a continuity diaphragm over the pier is used to create moment continuity; however, there is a risk of cracking of the field-cast joints and construction can be difficult when adjacent girders have different camber profiles. Given these challenges, adoption of the deck bulb-tee girder systems has been limited. Analytical investigation performed in part 1 of this series of papers indicated that using ultra-high-performance concrete (UHPC) can improve the performance of the field-cast joints and help overcome construction difficulties. This paper describes full-scale experimental testing performed as a follow-up to the analytical investigation. Longitudinal joints grouted with UHPC were tested under a combination of thermal and live load. A continuity diaphragm with partial UHPC was also tested under positive and negative moments over the pier.

Widening method for prestressed box concrete segmental bridges in Vietnam

This paper discusses how a two-lane prestressed box concrete bridge can be designed and constructed so that it can be widened easily into a three- or four-lane bridge in the future. The methods presented are the strutted box widening method (SBWM), which applies to concrete box girder bridges, and the strutted girder widening method (SGWM), which applies to precast concrete girder bridges. The finite element method (FEA) was used in this study to perform the tensile stress and deflection state of the girder in two cases non, and the use of SBWM with 03 different distances of strut: 2m, 3m, and 4m, respectively. The results showed that the SBWM with 4m of strut decreased by 2,9 times in the transverse tensile stress; the deflection is reduced by 2,98 times. This study contributes to the widening method of the reinforced concrete box girder bridge in the future.

ANALISIS STUDI KOMPARASI BETON PRECAST PADA PROYEK PEMBANGUNAN JEMBATAN PANGSAN DI PT. SANUR JAYA UTAMA

Current technological developments greatly influence construction projects, both in material procurement and contract models. Specifically for dealing with natural disasters with short recovery times, a Design and Build contract model is used. In the Pangsan Bridge Construction Project, the contractor procured precast concrete beams (Girders) which were produced at the factory and the installation process was carried out at the project. This contract is determined by direct appointment and this Regulation has been issued in PERPRES No. 54 of 2010 Article 38 Paragraph 1 stipulates that direct appointment of 1 (one) provider of Construction work/Other Services can be done in the case of exclusive circumstances; and/or Procurement of special goods/specific construction work/other services of a special nature. The precast concrete girder beam measures 0.65 m x 0.90 m with a length of 15.6 m, and is molded into 3 parts whose strength has been calculated. In terms of processing time, it is faster and costs more than conventional concrete. With production outside the project completion time is 1,5 months faster at a higher cost of 4,5 billion The length of conventional concrete is due to the implementation method which must be sequential and interrelated with a smaller cost of 3,8 billion So to meet the short time, the precast method is used even though it costs more.

Numerical validation and optimization of hybrid composite beam hull using multiple failure criteria

The number of structurally deficient bridges continues to increase due to corrosion of steel sections and concrete rebar, therefore the replacement of decaying structures and the development of innovative systems have become of high priority to extend the life span of newly built bridges. Hybrid Composite Beam (HCB) produced by Hillman is one of those systems that use a combination of materials i.e., concrete, steel, and Glass Fiber-Reinforced Polymer (GFRP) to integrate each main advantage in a single bridge beam structure. Despite its several apparent advantages; it is not widely spread as expected within the last decade. The HCB is manufactured of self-consolidating concrete (SCC), which is poured in the shape of a traditional arch and tied at its ends by high-strength tendons. A durable FRP composite hull encapsulates the SCC arch and the high-strength tying tendons in order to create a structural beam element for bridge applications. The HCB's design aims to provide pure compressive stresses to the concrete and pure tensile stresses to the steel. The current study performs a deep numerical investigation of the FRP hull instead of other components comprehensively studied. Numerical validation is performed for the deflection results on the experimentally tested Knickerbocker HCB Bridge, the deformations are validated at four stages of HCB manufacturing and testing. Further, the FRP hull strength ratios are quantified for the worst value of four failure criteria. The results showed an excess use of FRP material, where more than 90% of FRP areas have strength ratios of 5 to 50. The FRP hull thickness is minimized using Genetic Algorithm optimization under the worst case of loading. The results achieved more than 60% decrease in FRP weight, that led to only 20% cost difference between traditional precast concrete and HCB girders. It is finally concluded that the overdesign of FRP hull contributed to the high cost of HCB usage consequently inefficient market spread.

Application of high‐performance fibre reinforced concrete to precast girders for road bridges: Conceptual considerations and numerical analyses

AbstractHigh‐performance fiber‐reinforced concrete (HPFRC) can be considered a promising material for the construction of precast concrete girders for road bridges. This paper presents conceptual considerations and numerical analysis to support this statement. The HPFRC is a compromised alternative between FRC and UHPFRC mixes. Specifically, a tailor‐made mix design of HPFRC jointly developed by ACCIONA and the authors is presented, and then compared with the other types of fiber‐reinforced concretes collected from the technical literature. In addition, some trends observed in the database are described. This material characterization is followed by a conceptual analysis of the advantages of the application of HPFRC to road bridges. Specifically, a proposed bridge for the case of a 60 m‐span box girder is analyzed. A comparison between alternatives based on the use of HPFRC and conventional reinforced concrete is discussed. The results shed light on the viability of this material for bridge application. Specifically, the main finding show potential significant material savings in structural elements of the superstructure. Finally, ongoing and future research for a wide application to the construction sector are briefly discussed.