scholarly journals Experiment on the Segment Model of a Plain Concrete Arch Bridge Reinforced with UHPC Composite Arch Circle

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Zongshan Wang ◽  
Jianting Zhou ◽  
Jun Yang ◽  
Lei Chen ◽  
Weicheng Wang
Keyword(s):  
Bearing Capacity ◽  
Strain Distribution ◽  
High Performance ◽  
Failure Modes ◽  
High Performance Concrete ◽  
Plain Concrete ◽  
Original Structure ◽  
Interface Failure ◽  
Arch Models ◽  
Arch Bridges

This research aims to investigate the efficiency of strengthening of plain concrete (PLC) arches using UHPC. Thirteen segment arch models reinforced using normal concrete (NC, group N) or ultra-high performance concrete (UHPC, group U) were tested in this study. The failure mode, strain distribution, and calculation of bearing capacity of PLC arch bridges reinforced with UHPC arch circle were analyzed. The experimental results showed that the technology of chiseling and planting bars could provide sufficient bond strength on the interface between the UHPC reinforcement layer and NC substrate. Both groups showed one or two failure modes of the concrete crushing of the original structure and the interface failure. However, no cracks appeared in the UHPC reinforcement layer, indicating that there was still large bearing potential. The strain distribution of the whole section in group N was consistent with the plane section assumption. But, this phenomenon was not observed in group U since the strain of the reinforcement layer was ahead (R-side loading) or behind (L-side loading) that of original structures. A simplified calculation formula was used for calculating the bearing capacity of group U. It was accurate for specimens loaded on the L-side, and an enhancement coefficient of 0.15 should be considered for R-side loading specimens.

scholarly journals Experimental Behavior of Steel-Concrete Composite Girders with UHPC-Grout Strip Shear Connection

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 182
Author(s):  
Zhi-Qi He ◽  
Changxue Ou ◽  
Fei Tian ◽  
Zhao Liu
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Fatigue Testing ◽  
Ultimate Capacity ◽  
Horizontal Shear ◽  
Interface Failure ◽  
Interface Shear ◽  
Composite Action ◽  
Shear Connection ◽  
Push Out

This paper develops a new type of shear connection for steel-concrete composite bridges using Ultra-High Performance Concrete (UHPC) as the connection grout. The UHPC-grout strip shear connection is fabricated by preforming a roughened slot in the concrete deck slab, welding an embossed steel rib longitudinally to the upper flange of the steel girder, and casting the strip void between the slot and the steel rib with UHPC grout. The structural performance of the new connection was validated by two sets of experimental tests, including push-out testing of shear connectors and static and fatigue testing of composite beams. The results of push-out testing indicate that the UHPC-grout strip shear connection exhibits a significant improvement of ductility, ultimate capacity, and fatigue performance. The interface shear strength of the UHPC-grout strip connection is beyond 15 MPa, which is about three times that of the strip connection using traditional cementitious grouts. The ultimate capacity of the connection is dominated by the interface failure between the embossed steel and the UHPC grout. The results of composite-beam testing indicate that full composite action is developed between the precast decks and the steel beams, and the composite action remained intact after testing for two million load cycles. Finally, the trail design of a prototype bridge shows that this new connection has the potential to meet the requirements for horizontal shear.

Accelerated testing of super lightweight UHPC waffle deck under heavy vehicle simulator

2021 ◽  
Vol 16 (2-3) ◽  
pp. 61-74
Author(s):  
Sahar Ghasemi ◽  
Amir Mirmiran ◽  
Yulin Xiao ◽  
Kevin Mackie
Keyword(s):  
High Performance ◽  
Failure Modes ◽  
High Performance Concrete ◽  
High Strength ◽  
Heavy Vehicle ◽  
Wheel Load ◽  
Element Analysis ◽  
Vehicle Simulator ◽  
Pavement Testing ◽  
Heavy Vehicle Simulator

A super lightweight deck can enhance load rating and functionality of a bridge, especially those identified as structurally deficient. This study was aimed to develop and experimentally validate a novel bridge deck as an ultra-lightweight low-profile waffle slab of ultra-high-performance concrete (UHPC) with either carbon fiber reinforced polymer (CFRP) or high strength steel (HSS) reinforcement. The proposed system lends itself to accelerated bridge construction, rapid deck replacement in bridges with load restrictions, and bridge widening applications without the need to replace girders. Performance and failure modes of the proposed deck were initially assessed through extensive lab experiments and finite element analysis, which together confirmed that the proposed deck panel meets the AASHTO LRFD requirements. The proposed deck system is not susceptible to punching shear of its thin slab and fails in a rather ductile manner. To evaluate its long-term performance, the system was further tested under the dynamic impact of wheel load at the Accelerated Pavement Testing (APT) facility of the Florida Department of Transportation using a Heavy Vehicle Simulator (HVS).

Experimental Study on Bending Behavior of Timber Beams Reinforced with CFRP/AFRP Hybrid FRP Sheets

2011 ◽  
Vol 255-260 ◽  
pp. 728-732
Author(s):  
Qing Chun ◽  
Jian Wu Pan
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Bearing Capacity ◽  
Strain Distribution ◽  
Failure Modes ◽  
Bending Behavior ◽  
Timber Beams

Based on the experiment of timber rectangle beams made of pine and fir reinforced with CFRP/AFRP hybrid FRP (HFRP) sheets. The failure modes and bending bearing capacity and load-deflection curves and strain distribution at mid-span section were analyzed. The results showed that: Comparing with the specimens without being reinforced by HFRP, there is certain improvement in bending bearing capacity and stiffness of the specimens reinforced with HFRP respectively. Bending bearing capacity of the pine specimens improve 18.1%~62.0% and bending bearing capacity of the fir specimens improve 7.7%~29.7%. Stiffness of the pine specimens improve 13%~21%, and stiffness of the fir specimens improve 6%~10%. Based on the experimental data, the computing formulas of bending bearing capacity of timber rectangle beams made of pine and fir reinforced with HFRP were presented.

Experimental Research on Steel-High Performance Concrete Composite Bridge Towers and Piers

2011 ◽  
Vol 255-260 ◽  
pp. 1303-1306
Author(s):  
Chun Sheng Wang ◽  
Xin Xin Wang ◽  
Qian Wang
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultimate Bearing Capacity ◽  
Bridge Engineering ◽  
Good Prospect ◽  
Compression Tests ◽  
Composite Bridge ◽  
Bridge Tower

Steel-concrete composite bridge towers have the advantages of steel and concrete, they have a good prospect in bridge engineering. However, the applications and related researches of composite bridge towers in China are rare. Therefore, in this article, two types of steel-high performance concrete composite bridge tower and pier models, which had none and one row of longitudinal stud connectors, were designed. The axial compression tests were practiced on the two specimens, in order to study the influence of connectors on the mechanical properties of the composite bridge towers and piers. From the tests, the ultimate bearing capacity and failure mode were obtained, and the regularities of strains and deformations were also analyzed. The results show that setting up stud connectors on the composite towers and piers can improve the ductility and the ultimate bearing capacity obviously.

Study on the transfer and anchorage length of steel strand in ultra high performance concrete material

2020 ◽  
Vol 10 (2) ◽  
pp. 153-164
Author(s):  
Hui Zheng ◽  
Dongdong Zhou ◽  
Xinfeng Yin ◽  
Lei Wang
Keyword(s):  
Bond Strength ◽  
High Performance ◽  
Failure Modes ◽  
High Performance Concrete ◽  
Protective Layer ◽  
Experimental Results ◽  
Ultra High Performance Concrete ◽  
Anchorage Length ◽  
Pull Out ◽  
Steel Strand

Ultra-high-performance concrete (UHPC) material, a new type of cement-based composite material, is usually employed in the bridge engineering. The transfer and anchorage length of steel strand in UHPC material is different from that in ordinary concrete; nevertheless, few design standards are found that how to anchor the transfer and anchoring length of steel strand in UHPC material under normal curing. Through central pull-out test under the different conditions of protective layer thickness and embedded length, the load-slip curves, failure modes, and bond strength of 36 UHPC material specimens under normal curing were studied. The experimental results showed that the ultimate bond stress between UHPC material and steel strand under natural curing conditions is 7.01∼11.68 MPa. When the compressive strength of cube was 157 MPa; the bond strength under natural curing was smaller than that under thermal curing; when the thickness of the protective layer of steel strand with a diameter of 15.2 mm is greater than 30 mm, it had a little influence on bond strength. The regression analysis of the test results based on the experimental results proves that the recommended formulas for the design of transfer length and anchorage length of steel strand in UHPC material were in great agreement with the results of published studies.

scholarly journals Variation of the Pore Morphology during the Early Age in Plain and Fiber-Reinforced High-Performance Concrete under Moisture-Saturated Curing

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 975 ◽  
Author(s):  
Miguel Vicente ◽  
Jesús Mínguez ◽  
Dorys González
Keyword(s):  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Plain Concrete ◽  
Early Age ◽  
Geometrical Parameters ◽  
Pore Morphology ◽  
Fiber Reinforced ◽  
Concrete Mixtures ◽  
The One

In this paper, two concrete mixtures of plain concrete (PC) and steel fiber-reinforced high-performance concrete (SFRC) have been scanned in order to analyze the variation of the pore morphology during the first curing week. Six cylinders of 45.2-mm diameter 50-mm height were performed. All of the specimens were kept in a curing room at 20 °C and 100% humidity. A computed tomography (CT) scan was used to observe the internal voids of the mixtures, and the data were analyzed using digital image processing (DIP) software, which identified and isolated each individual void in addition to extracting all of their geometrical parameters. The results revealed that the SFRC specimens showed a greater porosity than the PC ones. Moreover, the porosity increased over time in the case of SFRC, while it remained almost constant in the case of PC. The porosity increased with the depth in all cases, and the lowest porosity was observed in the upper layer of the specimens, which is the one that was in contact with the air. The analysis of the results showed that the fibers provided additional stiffness to the cement paste, which was especially noticeable during this first curing week, resulting in an increasing of the volume of the voids and the pore size, as well as a reduction in the shape factor of the voids, among other effects.

Shear resistance of self-consolidating concrete beams — experimental investigations

2005 ◽  
Vol 32 (6) ◽  
pp. 1103-1113 ◽  
Author(s):  
M Lachemi ◽  
K M.A Hossain ◽  
V Lambros
Keyword(s):  
High Performance ◽  
Failure Modes ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Maximum Size ◽  
Shear Resistance ◽  
Resistance Mechanisms ◽  
Experimental Investigations ◽  
Self Consolidating Concrete ◽  
Aggregate Interlock

Self-consolidating concrete (SCC) is a new generation of high performance concrete known for its excellent deformability and high resistance to segregation and bleeding. Lack of information regarding in situ properties and structural performance of SCC is one of the main barriers to its acceptance in the construction industry. There is some concern among researchers and designers that SCC may not be strong enough in shear because of some uncertainties in mechanisms resisting shear — notably the aggregate interlock mechanism. Because of the presence of comparatively smaller amount of coarse aggregates in SCC, the fracture planes are relatively smooth as compared with normal concrete (NC) that may reduce the shear resistance of concrete by reducing the aggregate interlock between the fracture surfaces. The paper compares the shear resistance of SCC and NC based on the results of an experimental investigation on 18 flexurally reinforced beams without shear reinforcements. The test parameters include concrete type, maximum size of coarse aggregate, coarse aggregate content, and beam shear span-to-depth ratio. Shear strength, shear ductility, crack patterns, and failure modes of all experimental beams are compared to analyze the shear resistance mechanisms of SCC and NC beams in both pre- and post-cracking stages. The recommendations of this paper can be of special interest to designers considering the use of SCC in structural applications.Key words: self-consolidating concrete, shear resistance, shear resistance factor, aggregate interlock, dowel action.

Ductility and Deformation Performance of Hybrid Fiber Reinforced High Performance Concrete Shear Deep Beams

2013 ◽  
Vol 357-360 ◽  
pp. 858-862
Author(s):  
Sheng Bing Liu ◽  
Li Hua Xu
Keyword(s):  
High Performance ◽  
Failure Modes ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Orthogonal Experimental Design ◽  
Deep Beam ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Deep Beams ◽  
Splitting Failure

The shear tests were made on 18 different groups of deep beams with steel fiber and polypropylene fiber according to the orthogonal experimental design. For comparison, 2 groups of high performance concrete deep beams without fiber were conducted. Shear ductility and deformation performance of deep beams were analyzed quantitatively. Results illuminate that failure mode of high performance concrete shear deep beam is splitting failure, while hybrid fiber reinforced HPC shear deep beam has two failure modes (splitting failure and diagonal compression failure). The mixing of hybrid fiber makes rigidity of HPC deep beam increase obviously, the strain of web horizontal reinforcement and web vertical reinforcement decrease significantly. The catastrophe of strain of cracked concrete is also obviously smaller and the descending step of loaddeflection curve is flatter when adding hybrid fiber. Hybrid fiber can greatly increase shear ductility of deep beams and shear ductility is at the most increased by 40.7% whereas it can not change the brittleness of shear damage radically. The volume fraction of steel fiber plays the most important role in shear ductility whereas the shape of steel fiber has minimum effect among analyzed six factors.

Fracture Surface Measurement of Concrete with Respect to Loading Speed

2014 ◽  
Vol 982 ◽  
pp. 94-99 ◽  
Author(s):  
Michal Mára ◽  
Petr Maca
Keyword(s):  
Fracture Surface ◽  
Reverse Engineering ◽  
Impact Loading ◽  
High Performance ◽  
High Performance Concrete ◽  
Laser Scanner ◽  
Plain Concrete ◽  
3D Models ◽  
Measured Data ◽  
Surface Measurement

Reverse engineering is a specialization which was developed a lot in the 21st century. The major aim is researching and describing the principals and procedures of process and structures. Reverse engineering in civil engineering is used to describe the applied loadings which caused corruption or failure of a structure or it is used to reconstruct 3D models of the original object. The aim of this paper is to compare response to static and impact loading of two materials, i.e. plain concrete and high-performance concrete (HPC), with respect to the fracture surface area. These areas were scanned by the 3D laser scanner and they were evaluated in the graphic programs. The main objective of this paper is a presentation of measured data, which can be used to determine the size of the applied loadings using reverse engineering.

scholarly journals Synergetic Effect of Sugarcane Bagasse Ash with Low Modulus of Fiber Reinforced Concrete

2019 ◽  
Vol 8 (3) ◽  
pp. 7171-7175
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Research Work ◽  
Synergetic Effect ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Low Modulus ◽  
Sugar Cane Bagasse Ash

This research work has experimentally investigated on the effects of low modulus fibers (PP) used in concrete for the various percentages like 0. 0.5% and 1.0% (by volume fraction) along with different percentage of sugar cane bagasse ash from 0 to 15% replaced in Portland cement (by weight of binding material) for different mixes and tested for the various properties of high-performance concrete (HPC). This experimental test results indicated that the usage of SCBA is restricted up to 10% with 0.5% of PP (Polypropylene) along with 1.5% of superplasticizers produces the higher flexural strength was increased up to 78.30% and compressive strength of concrete was increased up to 25.80% when compared to control (plain) concrete at 28 days. Finally, the usage of low modulus fibre reinforced concrete to act as a corrosion inhibitor agent during the chloride attack than compared to high modulus fibers and reduce the plastic shrinkage due to excellent flexibility in concrete and also increases the life span.

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