Load transfer between thin steel plates and ultra-high performance concrete through different types of shear connectors

2021 ◽  
Vol 227 ◽  
pp. 111450
Author(s):  
Dominic Kruszewski ◽  
Arash E. Zaghi
Keyword(s):  
High Performance ◽  
Load Transfer ◽  
High Performance Concrete ◽  
Steel Plates ◽  
Ultra High Performance Concrete ◽  
Shear Connectors ◽  
Different Types ◽  
Thin Steel

The Determination of Frost Resistance on Ultra High Performance Concrete

2014 ◽  
Vol 1025-1026 ◽  
pp. 1005-1009 ◽  
Author(s):  
Michaela Kostelecká ◽  
Jiří Kolísko
Keyword(s):  
Frost Resistance ◽  
High Performance ◽  
High Performance Concrete ◽  
Silica Sand ◽  
Ultra High Performance Concrete ◽  
Concrete Technology ◽  
Normal Concrete ◽  
Different Types ◽  
High Range

The ultra high performance concrete (UHPC) has very special properties that are expressively different of normal concrete. Due to its high compression strength greater than 150 MPa, tensile strength greater than 20 MPa and improved durability, these represent significant advances in concrete technology. These materials include Portland cement, silica fume, quartz flour, fine silica sand, high-range water-reducer, water and either steel or organic fibres. Depending on the type of fibres used can influence the compressive strength. The article describes the tests of frost resistance on UHPC plates with different types of textiles armatures. The aim of the testing is describe influence of textiles armatures in UHPC matrix in extreme conditions.

Shear behavior of large stud shear connectors embedded in ultra-high-performance concrete

2020 ◽  
Vol 23 (16) ◽  
pp. 3401-3414
Author(s):  
Yuqing Hu ◽  
Huiguang Yin ◽  
Xiaomeng Ding ◽  
Shuai Li ◽  
JQ Wang
Keyword(s):  
Numerical Analysis ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Slab ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Ultra High Performance Concrete ◽  
Shear Connectors ◽  
Push Out ◽  
Static Shear

In this article, the static shear behavior of large-headed studs embedded in ultra-high-performance concrete was investigated by push-out test and numerical analysis. A total of nine push-out specimens with single and grouped studs embedded in ultra-high-performance concrete and normal strength concrete slabs were tested. In the testing process, only shank failure appeared without cracks occurring on the surface of ultra-high-performance concrete slab when the steel–ultra-high-performance concrete specimens reached ultimate shear capacity. The shear capacity of specimens with large studs embedded in ultra-high-performance concrete slab increased by 10.6% compared those in normal concrete, and the current design codes such as Eurocode4, AASHTO LFRD 2014, and GB50017-2003 all underestimate the shear capacity of such kind of steel–ultra-high-performance concrete composite structures according to experimental results. Numerical models were established using ABAQUS with introducing damage plasticity material model. The influence of stud diameter, concrete strength, thickness of clear cover, and spacing of studs on the static shear behavior was thoroughly investigated via parametric analysis. Based on the experimental and numerical analysis, the existence of wedge block and the decrease of axis force are beneficial for improving the shear capacity of stud shear connectors.

scholarly journals Load Transfer Test of Post-Tensioned Anchorage Zone in Ultra High Performance Concrete

Engineering ◽  
2015 ◽  
Vol 07 (03) ◽  
pp. 115-128 ◽  
Author(s):  
Jee-Sang Kim ◽  
Changbin Joh ◽  
Yoon-Seok Choi
Keyword(s):  
Transfer Test ◽  
High Performance ◽  
Load Transfer ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete ◽  
Post Tensioned

Ultra-High-Performance Concrete Shear Keys in Concrete Bridge Superstructures

2020 ◽  
pp. 036119812096472
Author(s):  
Elsy Y. Flores ◽  
Jordan Varbel ◽  
William K. Toledo ◽  
Craig M. Newtson ◽  
Brad D. Weldon
Keyword(s):  
High Performance ◽  
Load Transfer ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Surface Preparation ◽  
Ultra High Performance Concrete ◽  
Direct Tension ◽  
Girder Bridges ◽  
Grouting Material ◽  
Shear Keys

This research investigated the use of locally produced, non-proprietary ultra-high-performance concrete (UHPC) as a grouting material to repair deteriorated shear keys. Shear keys are used in adjacent girder superstructures to produce monolithic behavior and load transfer across the structure. Shear key degradation can jeopardize the integrity of the structure. Transportation agencies have reported that 75% of distress in adjacent girder bridges is because of cracking and de-bonding along shear keys. Previous research has shown that locally produced UHPC has excellent mechanical and durability properties. UHPC has also been shown to have good bonding characteristics that are desirable in a potential grouting material. Bond strength between UHPC grout and substrate concrete was evaluated using slant-shear and direct tension tests. Results showed that adequate bond was achieved at 7 days. Low strengths at 28 days were observed because of low strength of the substrate concrete. Shrinkage of UHPC grout was also investigated. Shrinkage at 28 days was less than 600 µstrain which is acceptable for repair practices. Full-scale testing was used to evaluate load-deflection behavior of channel girder assemblages with grouted shear keys. Results showed that UHPC grout and non-shrink grout had similar mechanical performance. Excellent bond was achieved with all grouts, even with minimal surface preparation. The similar performances of the non-shrink grout and the UHPC grout indicates that UHPC grout does not provide a mechanical benefit over the non-shrink grout.

scholarly journals EFEITO DA ADIÇÃO DE FIBRAS DE AÇO E POLIMÉRICAS NA RESISTÊNCIA À COMPRESSÃO DO CONCRETO DE ULTRA ALTO DESEMPENHO

2020 ◽  
Vol 16 (1) ◽  
pp. 26-35
Author(s):  
Carlos Eduardo Tino Balestra ◽  
Jennifer Stephane Ozelame ◽  
Gustavo Savaris
Keyword(s):  
High Performance ◽  
New Technologies ◽  
High Performance Concrete ◽  
Steel Fibers ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
Residual Resistance ◽  
Different Types ◽  
Polyethylene Fibers ◽  
Rupture Behavior

RESUMO: A exigência de materiais com desempenho superior aos utilizados usualmente na construção civil impulsiona pesquisas que visam o desenvolvimento de novas tecnologias. Neste contexto, surgem os concretos de ultra alto desempenho reforçados com fibras (UHPFRC), que se destacam pelas elevadas resistências à compressão e à tração e maior ductilidade em relação a um concreto convencional. O presente trabalho teve como objetivo principal avaliar experimentalmente a resistência à compressão e comportamento pós ruptura de UHPFRC com diferentes tipos e dosagens de fibras, utilizando materiais disponíveis no mercado brasileiro, visando o emprego deste material nos processos construtivos atuais. A partir de um traço de concreto de ultra alto desempenho foram definidas misturas de UHPFRC com fibras de aço e de fibras de polietileno utilizando volumes de 0,5% e 1% de fibras. Os resultados obtidos foram comparados a um concreto de referência sem fibras, demonstrando que as fibras melhoram a ductilidade do concreto e provém uma resistência residual ao mesmo, sendo observados, após sua fratura, picos de recuperação graças à melhor aderência das fibras ao concreto. Além disso, para ambas as fibras, uma maior quantidade de fibras auxiliou a combater as rupturas bruscas observadas após concretos sem fibras esgotarem sua capacidade resistente. ABSTRACT: The demand for materials with higher performance than those usually used in civil construction stimulate researches aimed at the development of new technologies. In this context, ultra high performance fibers reinforced concrete (UHPFRC) stands out due to the high compressive and tensile strengths and higher ductility compared to conventional concrete. The present work had as main objective to evaluate experimentally the compressive strength and post - rupture behavior of UHPFRC with different types and dosages of fibers, using materials available in Brazil, aiming the use of these material in the current constructive processes. UHPFRC mixtures with steel fibers and polyethylene fibers using 0.5% and 1% fiber volumes were defined from an ultra high performance concrete mixture. The results obtained were compared to a reference concrete without fibers, demonstrating that the fibers improve the ductility of the concrete and provide a residual resistance after the exemplar fracture, recovery peaks due to the better adhesion of the fibers to the concrete. In addition, for both fibers, a greater amount of fibers helped to avoid sudden ruptures observed after concrete without fibers reached their resistant capacity.

Prefabricated Box Girder with Ultra High Performance Concrete

2018 ◽  
Author(s):  
Keli Xiao ◽  
Yanjun Jin ◽  
Lin Li ◽  
Wei He ◽  
Duan Xinlong
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Slab Thickness ◽  
Low Carbon ◽  
Ultra High Performance Concrete ◽  
Dead Weight ◽  
Box Girder ◽  
Ordinary Concrete ◽  
Shear Connectors ◽  
Thin Beams

<p>In order to solve traffic difficulty brought by the bridge construction in the city, and difficult transportation of beams, this paper puts forward the prefabricated-box-girder bicycle viaduct with ultra - high performance concrete (UHPC) through which will achieve light and thin beams, easy transportation and rapid construction. Based on the bicycle viaduct with 5.5m in width, this paper not only designs a prefabricated ribbed thin-walled box girder with 30m in span, including the detailed design of prefabricated segment stiffeners, shear connectors and external prestressing but also compares the UHPC box girder with ordinary concrete box girder and steel box girder. The research shows that with the application of UHPC in prefabricated viaduct in city, the ratio of height to span of beams and the slab thickness decrease to 1/30 and 10cm respectively, the dead weight is 50% lower than that of the ordinary concrete beams and the 3m long lifting weight is only 10 tons. Light and thin beams are suitable for transportation in city because of their low requirements for transportation and hoisting equipment. UHPC beams have no steel bars and own the advantages of dense texture, good durability, low maintenance costs, reflecting the concept of low carbon environmental protection and green bridge.</p>

Push-Out Test on Shear Connectors Embedded in UHPC

2013 ◽  
Vol 351-352 ◽  
pp. 50-54 ◽  
Author(s):  
Jee Sang Kim ◽  
Sang Hyeok Park ◽  
Chang Bin Joh ◽  
Jong D.K. Kwark ◽  
Eun Suk Choi
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Ultra High Performance Concrete ◽  
Shear Connectors ◽  
Aspect Ratios ◽  
High Durability ◽  
Load Carrying ◽  
Push Out

The various push-out tests have been performed to investigate the load carrying capacity and ultimate behavior of headed studs in UHPC (Ultra High Performance Concrete), which has high compressive and tensile strength as well as high durability compared to ordinary concrete. The test program included the studs with a diameter of 16mm and 22mm for various aspect ratios (height to depth ratio of a stud) and cover depths. This paper presents the main results of the experimental investigations.

Design of Various Shear Connectors for Repair of Corroded Steel Girders with Ultra-High Performance Concrete

2019 ◽  
Vol 2673 (2) ◽  
pp. 521-530 ◽  
Author(s):  
Dominic Kruszewski ◽  
Arash E. Zaghi
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
The United States ◽  
Extensive Study ◽  
Bottom Flange ◽  
Load Path ◽  
Ultra High Performance Concrete ◽  
Shear Connectors ◽  
Repair Procedure ◽  
Bridge Girder

Corrosion accounts for approximately 20% of the structurally deficient bridges in the United States, causing a massive backlog of rehabilitation projects. The current repair procedure for corroded bridge girders is expensive, slow to implement, and necessitates complete closure of the bridge. Through an extensive study supported by the Connecticut Department of Transportation, a novel repair method has been developed to rapidly restore the strength of corroded bridge girder ends with minimal traffic interruption. First, shear connectors in the form of headed studs are welded on the uncorroded web plate above the bearing. Next, formwork is placed and ultra-high-performance concrete (UHPC) is cast down to the bottom flange. This creates an alternate load path around the section loss. Based on the experimental results, it may be concluded that the implementation of the repair reduces the strains on the web plate and strengthens the bridge girder, allowing it to surpass its original capacity. However, the success of the repair centers around the performance of the shear connectors. In addition to headed studs, threaded bars and UHPC dowels in perforated web were evaluated experimentally as alternative shear-transfer mechanisms. This paper presents the repair design objectives and considerations for a realistic girder end utilizing different shear connectors to demonstrate the flexibility and versatility of the repair. The details of the designs are illustrated to facilitate the transition of the research findings to practice.

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