scholarly journals Seismic Performance of Pre-Fabricated Segmental Bridges With An Innovative Layered-UHPC Connection

2021 ◽  
Author(s):  
Ruilong WANG ◽  
Biao MA ◽  
Xu CHEN
Keyword(s):  
Seismic Performance ◽  
High Performance ◽  
High Performance Concrete ◽  
Design Procedure ◽  
Engineering Practice ◽  
Accelerated Bridge Construction ◽  
Ultra High Performance Concrete ◽  
Promising Alternative ◽  
Key Issues ◽  
Ductile Component

Abstract Ultra-high-performance concrete (UHPC) has been regarded as promising alternative to provide reliable connections between difference segments (e.g., columns and pier footing/cap) during accelerated bridge construction (ABC) procedures. This paper proposes an innovative layered-UHPC connection for the pre-fabricated segmental (PFS) pier, whose seismic performance was validated through quasi-static experiment. The corresponding design procedure for PFS pier with this type of connections is presented based on the test results. The layered-UHPC connection ensures the emulative performance of pre-fabricated bridge as cast-in-place (CIP) ones, as well as provides greater economic efficiency than traditional UHPC connections. Based on experimental results, key issues concerning this connection, including the tensile behavior of UHPC, height of connection region, thickness of UHPC layer and steel bars in grouting bed, are presented and discussed. Then a seismic design procedure is proposed utilizing the capacity protection philosophy widely adopted in design specifications. The layered-UHPC connection is expected as capacity-protected component without damage, since it provides anchorage for steels extended from columns and pier cap/footing. While the pre-fabricated region is designed as ductile component undergoing nonlinearity during strong earthquakes. Following the detailed elaborations about the design philosophy, requirement and implementation steps, this procedure is further presented through illustration examples using PFS piers with various heights. The results show that PFS piers designed according to this procedure could meet the requirement under both frequent and rare earthquakes. Note that the PFS piers with this layered-UHPC connections could be designed similar to and emulative as CIP ones, which is believed friendly to designers in engineering practice.

Seismic performance of seawater and sea sand concrete-filled ultra-high performance concrete tubes under low-cycle reversed lateral loading

2020 ◽  
pp. 136943322098052
Author(s):  
Gang Liu ◽  
Bo Shan ◽  
Dade Lai ◽  
Fucai Liu ◽  
Yan Xiao
Keyword(s):  
Compressive Strength ◽  
Seismic Performance ◽  
High Performance ◽  
Composite System ◽  
High Performance Concrete ◽  
Lateral Loading ◽  
Ultra High Performance Concrete ◽  
Sea Sand ◽  
Seismic Design Code ◽  
Marine Engineering

Seawater and sea sand concrete (SWSSC) filled ultra-high performance concrete (UHPC) tube (SFUHPC tube) column is a cement-based tubular composite column, which combines the excellent compressive strength and toughness of UHPC and lateral confining action from fiber reinforced polymer (FRP) hoops. The novel composite system has the potential to be used in marine engineering. The aims of this paper focus on evaluating the seismic performance of SFUHPC tube columns for being designed in costal and marine engineering. A series of low-cycle reversed lateral loading tests were conducted on five relatively large-scale specimens. FRP hoop volumetric ratio, compressive strength of filling SWSSC, and the types of FRP bar were selected as test parameters in this investigation. The failure modes, hysteretic responses and effects of main parameters were studied and discussed. SFUHPC tube columns exhibited flexural failure mode without visible spalling of the UHPC cover. It is noteworthy that the limit plastic drift ratios of all SFUHPC tube columns exceed the specified limits (0.02) in accordance to the rare earthquake requirement in seismic design code. The current study reveals that the proposed composite columns have acceptable ductility and relatively reliable lateral resistant performance for being used in the marine engineering. From the point of view of seismic performance, filling high strength SWSSC in UHPC tube is acceptable for the proposed composite system.

New Connection Detail to Connect Precast Column to Cap Beam using Ultra-High-Performance Concrete in Accelerated Bridge Construction Applications

2018 ◽  
Vol 2672 (41) ◽  
pp. 207-220 ◽  
Author(s):  
Mohamadreza Shafieifar ◽  
Mahsa Farzad ◽  
Atorod Azizinamini
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Experimental Program ◽  
Accelerated Bridge Construction ◽  
Ultra High Performance Concrete ◽  
Bridge Construction ◽  
Construction Time ◽  
Element Analysis ◽  
Displacement Ductility

Accelerated bridge construction (ABC) is a paradigm change in delivery of bridges. ABC minimizes the traffic interruption, enhances safety to public and workers by significantly reducing on-site construction activities, and results in longer-lasting bridges. The use of precast elements is gaining attention owing to inherent benefits of accelerated construction. Designing an economical connection is one of the main concerns for these structures. New improved materials such as ultra-high-performance concrete (UHPC) with superior characteristics can provide solutions for joining precast concrete elements. In this paper two types of column to cap beam connection using UHPC are proposed for seismic and non-seismic regions. Among the merits of the proposed details, large tolerances in construction and simplicity of the connection can be highlighted which facilitates and accelerates the on-site construction time. The experimental program was carried out to evaluate the performance and structural behavior of the proposed connections. Four specimens were subjected to constant axial compressive loads and cyclic lateral loading. Results of the experiment showed that the displacement ductility of the specimens, incorporating suggested details, demonstrated adequate levels of displacement ductility. More importantly, the proposed connections prevented the damage into capacity protected element—in this case the cap beam. Analytical and nonlinear finite element analysis on the specimens was carried out to better comprehend the behavior of the proposed connections.

Rapid Bridge Replacement – Learning from the USA

2018 ◽  
Author(s):  
Charlotte Murphy
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Accelerated Bridge Construction ◽  
Ultra High Performance Concrete ◽  
Concrete Construction ◽  
The Usa ◽  
The Uk ◽  
Concrete Elements ◽  
Innovative Techniques

<p>The IStructE Pai Lin Li Travel Award funded the author for an investigation into current practice precast concrete construction in the USA. The Federal Highways Administration (FHWA) in the USA has invested heavily in research into precast concrete construction through its Accelerated Bridge Construction (ABC) programme. The FHWA’s research has had a focus on innovative techniques for joining structural precast concrete elements together.<p>Grouted splice couplers and Ultra-High Performance Concrete are the two key enabling techniques that were investigated in this research. The replacement of 6 36m span bridges over Interstate 78 in Pennsylvania used these techniques and completed each bridge replacement in 40 days. This paper investigates the development of these techniques, the benefits they could have on the UK construction industry and what actions need to be taken to realise those benefits.

Estimation of Shear Behavior of Ultra High Performance Concrete I Girder without Shear Stirrups

2012 ◽  
Vol 525-526 ◽  
pp. 557-560
Author(s):  
Jung Woo Lee ◽  
Chang Joh ◽  
E.S. Choi ◽  
I.J. Kwak ◽  
Byung Suk Kim
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Crack Opening ◽  
Experimental Studies ◽  
Design Procedure ◽  
High Strength ◽  
Shear Behavior ◽  
Ultra High Performance Concrete ◽  
Shear Design ◽  
Loss Of Strength

Thinner and lighter members can be designed by utilizing the high stiffness and toughness, and high compressive strength of Ultra High Performance Concrete (UHPC), which reaches up to 180MPa. This high strength and ductile tensile behavior of UHPC makes it possible to design the web of the UHPC I Girder without conventional shear stirrups, which makes the UHPC I girder slender, light and economical. However, establishing shear design procedure for UHPC I girders without stirrups requires additional theoretical and experimental studies. This paper investigated shear behavior of UHPC I girder without shear stirrups. The test results show, in spite of no shear stirrups, test specimens have high ductility due to the bridging action of steel fibers against crack opening. UHPC I girders without shear stirrups tested show gradual increase of strength after initial cracking instead of brittle loss of strength as expected from the ordinary reinforced concrete I girders without stirrups. The decrease of the shear span-depth ratio increase the shear strength of the UHPC I girder without stirrups.

scholarly journals Effect of Fiber, Cement, and Aggregate Type on Mechanical Properties of UHPC

2021 ◽  
Vol 7 (8) ◽  
pp. 1290-1309
Author(s):  
Esmail Shahrokhinasab ◽  
Trevor Looney ◽  
Royce Floyd ◽  
David Garber
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Particle Packing ◽  
High Price ◽  
Accelerated Bridge Construction ◽  
Ultra High Performance Concrete ◽  
New Class ◽  
The Us

Ultra-High Performance Concrete (UHPC) is a new class of concrete that differentiates itself from other concrete materials due to its exceptional mechanical properties and durability. It has been used in structural rehabilitation and accelerated bridge construction, structural precast applications, and several other applications in the past decades. The mechanical properties of UHPC include compressive strength greater than 124 MPa (18 ksi) and sustained post cracking tensile strength greater than 5 MPa (0.72 ksi) when combined with steel, synthetic or organic fibers. Proprietary, pre-bagged mixtures are currently available in the market, but can cost about 20 times more than traditional concrete. This high price and the unique mixing procedure required for UHPC has limited its widespread use in the US and has motivated many researchers to develop more economical versions using locally available materials. The objective of this study was to investigate the effect of different proportions of typical UHPC mixture components on the mechanical properties of the mixtures. Particle packing theory was used to determine a few optimal mixture proportions and then modifications were made to investigate the effect. A compressive strength of around 124 MPa (18 ksi) was achieved without using any quartz particles in the mixture design. Doi: 10.28991/cej-2021-03091726 Full Text: PDF

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