scholarly journals Analytical Assessment of Bending Ductility in FRP Strengthened RHSC Beams

2018 ◽  
Vol 4 (11) ◽  
pp. 2719 ◽  
Author(s):  
Houman Ebrahimpour Komleh ◽  
Ali Akbar Maghsoudi
Keyword(s):  
Prestressed Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Prediction Equation ◽  
Flexural Behavior ◽  
Limit Values ◽  
Practical Applications ◽  
Ductility Index ◽  
Fiber Reinforced Polymer Composites ◽  
Curvature Ductility

Over the past few years, a wide use of externally-bonded fiber-reinforced polymer composites (EB-FRP), for rehabilitation, strengthening and repair of existing/deteriorated reinforced/prestressed-concrete (RC/PC) structures has been observed. This paper presents a nonlinear iterative analytical approach conducted to investigate the effects of concrete strength, steel-reinforcement ratio and externally-reinforcement (FRP) stiffness on the flexural behavior and the curvature ductility index of the FRP-strengthened reinforced high-strength concrete (RHSC) beams. Analysis results using the proposed technique have shown very good agreement with the experimental data of FRP-strengthened/non-strengthened RHSC beams, regarding moment–curvature response, ultimate moment and failure mode. Also, a newly prediction equation for the curvature ductility index of FRP strengthened RHSC beams has been developed and verified. Then, converting equation of the curvature ductility index to energy one is proposed. Results indicate that the proposed predictions for the curvature and energy ductility indices are accurate to within 1.87% and 3.03% error for practical applications, respectively. Finally, limit values for these bending ductility indices, based on different design codes’ criterion, are assessed and discussed.

scholarly journals An Experimental Study on the Ductility and Flexural Toughness of Ultrahigh-Performance Concrete Beams Subjected to Bending

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2225 ◽  
Author(s):  
In-Hwan Yang ◽  
Jihun Park ◽  
The Quang Bui ◽  
Kyoung-Chul Kim ◽  
Changbin Joh ◽  
...  
Keyword(s):  
Steel Fiber ◽  
Load Capacity ◽  
High Strength ◽  
Absorption Capacity ◽  
Flexural Behavior ◽  
Fiber Volume ◽  
Clear Trend ◽  
Flexural Toughness ◽  
Failure Patterns ◽  
Curvature Ductility

Ultrahigh-performance concrete (UHPC) and high-strength concrete (HSC) are currently widely used because of their distinct superior properties. Thus, a comprehensive comparison of the flexural behavior of UHPC and HSC beams is presented in this study. Nine UHPC beams and three HSC beams were subjected to pure bending tests to investigate the effect of various reinforcement ratios and steel fiber volume contents on the cracking and failure patterns, load-deflection behavior, ductility, and flexural toughness of these beams. The addition of steel fibers in the UHPC improved the energy absorption capacity of the beams, causing the UHPC beams to fail via rebar fracture. The deflection and curvature ductility indices were determined and compared in this study. The ductility indices of the HSC beam tended to decrease sharply as the rebar ratio increased, whereas those of the UHPC beam did not show a clear trend with respect to the rebar ratio. In addition, a comparison between the results in this study and the results from previous studies was performed. In this study, the addition of steel fiber contents up to 1.5% in UHPC increased the load capacity, ductility, and flexural toughness of the UHPC beams, whereas the addition of a steel fiber content of 2.0% did not significantly increase the ductility or flexural toughness of the UHPC beams.

scholarly journals Flexural behavior of hybrid GFRP - concrete railway sleepers

2019 ◽  
Vol 12 (4) ◽  
pp. 738-765
Author(s):  
A. C. L. de AZEVEDO ◽  
A. M. A. J. TEIXEIRA ◽  
L. A. V. CARNEIRO
Keyword(s):  
Prestressed Concrete ◽  
Flexural Modulus ◽  
High Strength ◽  
Flexural Behavior ◽  
Polymer Concrete ◽  
Mechanical Resistance ◽  
Glass Fiber Reinforced ◽  
Hybrid Beams ◽  
Feasible Alternative ◽  
Rupture Mode

Abstract This paper aims to present the flexural behavior of hybrid GFRP (glass fiber reinforced polymer) concrete beams as sleepers to railway application. It was tried to obtain sleepers with adequate mechanical resistance, not susceptible to corrosion, durable and lighter than the sleepers in prestressed concrete. Pultruded fiberglass and polyester resin profiles were filled with high strength concrete and polyolefin fiber in the following proportions by volume: 1% and 2.5%. The beams were 1.06 meters long and had a 76 mm x 76 mm x 6 mm cross section, corresponding to a reduced model in a 1: 2.64 scale of a 2.80 meters long sleeper. In the bending tests, the load was applied at the center of the sleeper, as provided in the Brazilian standard NBR 11709 (2015) and American standard AREMA (2016). During the tests the applied load, the vertical deflection and the longitudinal tensile and compression deformations were measured in the center of the span. The influence of fiber addition on the strength, rupture mode and flexural modulus of elasticity of the hybrid beams was analyzed. Finally, the hybrid sleeper performance was compared to that of the prestressed concrete monoblock sleeper. The results obtained were satisfactory, indicating that the proposed hybrid sleeper is a constructively and technically feasible alternative.

scholarly journals Steel-Concrete Composite Beams with Precast Hollow-Core Slabs: A Sustainable Solution

2021 ◽  
Vol 13 (8) ◽  
pp. 4230
Author(s):  
Felipe Piana Vendramell Ferreira ◽  
Konstantinos Daniel Tsavdaridis ◽  
Carlos Humberto Martins ◽  
Silvana De Nardin
Keyword(s):  
Concrete Strength ◽  
High Strength ◽  
High Volume ◽  
Composite Beams ◽  
Reinforcement Rate ◽  
Economic Benefits ◽  
Embodied Energy ◽  
Flexural Behavior ◽  
Hollow Core ◽  
Partial Interaction

Industrialization of construction makes building operation more environmental friendly and sustainable. This change is necessary as it is an industry that demands large consumption of water and energy, as well as being responsible for the disposal of a high volume of waste. However, the transformation of the construction sector is a big challenge worldwide. It is also well known that the largest proportion of the material used in multistory buildings, and thus its carbon impact, is attributed to their slabs being the main contributor of weight. Steel-Concrete composite beams with precast hollow-core slabs (PCHCSs) were developed due to their technical and economic benefits, owing to their high strength and concrete self-weight reduction, making this system economical and with lower environmental footprint, thus reducing carbon emissions. Significant research has been carried out on deep hollow-core slabs due to the need to overcome larger spans that resist high loads. The publication SCI P401, in accordance with Eurocode 4, is however limited to hollow-core slabs with depths from 150 to 250 mm, with or without a concrete topping. This paper aims to investigate hollow-core slabs with a concrete topping to understand their effect on the flexural behavior of Steel-Concrete composite beams, considering the hollow-core-slab depth is greater than the SCI P401 recommendation. Consequently, 150 mm and 265 mm hollow-core units with a concrete topping were considered to assess the increase of the hollow core unit depth. A comprehensive computational parametric study was conducted by varying the in situ infill concrete strength, the transverse reinforcement rate, the shear connector spacing, and the cross-section of steel. Both full and partial interaction models were examined, and in some cases similar resistances were obtained, meaning that the same strength can be obtained for a smaller number of shear studs, i.e., less energy consumption, thus a reduction in the embodied energy. The calculation procedure, according to Eurocode 4 was in favor of safety for the partial-interaction hypothesis.

scholarly journals High-strength concrete technology for manufacturing reinforced concrete sleepers from prestressed reinforced concrete

2021 ◽  
Vol 264 ◽  
pp. 02040
Author(s):  
Urinbek Turgunbaev ◽  
Movluda Umirova
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Cement Stone ◽  
Chemical Additives ◽  
Concrete Technology ◽  
Complex Chemical ◽  
Initial Stage ◽  
Sufficient Strength

The properties of concrete with complex chemical additives to improve the technology for the production of sleepers from prestressed concrete are discussed in the article. With the use of complex chemical additives under heat-moisture processing, at a temperature of 40°C, there was no decrease in the strength of the cement stone and sufficient strength at the initial stage of the curing period, 44.7 MPa; concrete strength was determined with the addition of Glenium 27 S - 1.0% and the hardening accelerator Master X -Seed 100 - 1.2%. Thus, the use of complex chemical additives makes it possible to solve the problem of achieving the necessary early high strength of concrete to implement low-temperature technology in the production of reinforced concrete sleepers.

Experimental Study on Flexural Behavior of Damaged Reinforced Concrete Beams Strengthened with CFRP

2014 ◽  
Vol 507 ◽  
pp. 306-310 ◽  
Author(s):  
Bin Jia ◽  
Jin Xue ◽  
Jun Mo ◽  
Chun Tao Zhang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Concrete Strength ◽  
High Strength ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Failure Model ◽  
High Coherence

Abstract. In the view of the project problem that concrete strength grade is lower than C15in reinforced concrete beam, we consider a composite technology strengthened with CFRP, and do some monotonic loading experiments on these beams with eight different methods, and discuss the beam force behavior including ultimate bearing capacity, failure model and crack propagation. This paper finds out that the composite reinforced scheme, which with ticking trough, planting steel displaces concrete and gluing and then pasting CFRP, has a remarkable improvement than pasting CFRP immediately, and that there is a high coherence workability in the old and new concrete, so we can give full play to their role as the CFRP high strength.

Flexural behavior of high-strength, steel-reinforced, and prestressed concrete beams

2021 ◽  
Vol 15 (1) ◽  
pp. 227-243
Author(s):  
Qing Jiang ◽  
Hanqin Wang ◽  
Xun Chong ◽  
Yulong Feng ◽  
Xianguo Ye
Keyword(s):  
Prestressed Concrete ◽  
High Strength Steel ◽  
Concrete Beams ◽  
High Strength ◽  
Flexural Behavior

scholarly journals A Comparative Experimental Study on the Flexural Behavior of High-Strength  Fiber-Reinforced Concrete and High-Strength Concrete Beams

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
In-Hwan Yang ◽  
Changbin Joh ◽  
Kyoung-Chul Kim
Keyword(s):  
Reinforced Concrete ◽  
High Strength Concrete ◽  
Concrete Beams ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Flexural Behavior ◽  
Flexural Toughness ◽  
Strength Concrete ◽  
Ductility Index ◽  
High Strength Fiber

The flexural responses of high-strength fiber-reinforced concrete (HSFRC) beams and high-strength concrete (HSC) beams are compared in this study. A series of HSFRC and HSC beams were tested under pure flexural loading. The effects of the type of concrete, compressive strength of the concrete, and tensile rebar ratio on the flexural behavior of the concrete beams were investigated. The flexural behavior of the HSFRC and HSC beams including the induced crack and failure patterns, load and deflection capacity, crack stiffness, ductility index, and flexural toughness was compared. The crack stiffness of the HSC and HSFRC beams increased with the rebar ratio. For the same rebar ratios, the crack stiffness of the HSFRC beams was much greater than that of the HSC beams. The ductility index of the HSC beams decreased sharply with an increase in the rebar ratio, but the ductility index of the HSFRC beams did not show a clear decrease with increasing rebar ratio. The flexural toughness of the HSFRC beams was greater than that of the HSC beams at higher rebar ratios of 1.47% and 1.97%, indicating that the energy absorption of the HSFRC beams was greater than that of the HSC beams. Test results also indicated that HSFRC developed better and more consistent ductility with higher rebar ratio. In addition, the tested bending strength and sectional analysis results were compared.

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