Model for estimating the flexural performance of concrete reinforced with hooked end steel fibers using three‐point bending tests

To model the behavior of precast segmental tunnel linings under thrust jack loading, cylindrical concrete columns, subjected to concentrated loads, are investigated. Specifically, uniaxial compressive tests have been performed on specimens made with self-compacting concrete and reinforced with two different amounts of steel fibers (0, 30 kg/m3, respectively). In addition, to measure concrete properties, three point bending tests have been carried out in accordance with code rules. As a result, not only the fracture toughness of concrete in compression is improved, but also the ultimate and the maximum splitting loads are remarkably increased by the presence of long fibers. Accordingly, a new formulation of the classical Leonhardt’s approach is eventually proposed. Finally, based on the results of the present research, it seems reasonable to replace reinforced concrete with SFRSCC in structures subjected to high concentrated loads.

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Flexural Performance of Reinforced Concrete Built-up Beams with SIFCON

Engineering and Technology Journal ◽

10.30684/etj.v38i5a.501 ◽

2020 ◽

Vol 38 (5A) ◽

pp. 669-680

Author(s):

Ghazwan K. Mohammed ◽

Kaiss F. Sarsam ◽

Ikbal N. Gorgis

Keyword(s):

Reinforced Concrete ◽

Ultimate Load ◽

Concrete Beams ◽

Steel Fibers ◽

Reinforced Concrete Beams ◽

Load Carrying Capacity ◽

Conventional Concrete ◽

Flexural Performance ◽

Load Carrying ◽

Fiber Concrete

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.

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Investigation of the Deformation Twins on the Bending Cross Section of TA2 Titanium Sheet

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.837.41 ◽

2020 ◽

Vol 837 ◽

pp. 41-45

Author(s):

Shuai Sun ◽

Kai Hua Liu

Keyword(s):

Electron Backscatter Diffraction ◽

Testing Machine ◽

Pure Titanium ◽

Titanium Sheet ◽

Bending Tests ◽

Three Point Bending ◽

Deformation Twins ◽

Ebsd Technique ◽

Backscatter Diffraction ◽

Deformation Area

In order to determine the evolution features of deformation twins for TA2 commercial pure titanium (cp-TA2), the TA2 samples were bent under different bending angles in three-point bending tests via a universal testing machine. The electron backscatter diffraction (EBSD) technique was applied to identify the grain boundaries (GBs) and twin boundaries (TBs) in the bending areas. The results reveal that the type of deformation area would effect the evolution of different deformation twins. It is inferred that the state of stress would promote the multiplication of the same type of deformation twins.

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A Study of the Flexural Behavior of Fiber-Reinforced Concretes Exposed to Moderate Temperatures

Materials ◽

10.3390/ma14133522 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3522

Author(s):

Marta Caballero-Jorna ◽

Marta Roig-Flores ◽

Pedro Serna

Keyword(s):

Steel Fiber ◽

Flexural Behavior ◽

Polypropylene Fibers ◽

Fiber Reinforced ◽

Insulation System ◽

Bending Tests ◽

Synthetic Fibers ◽

Three Point Bending ◽

Lower Performance ◽

Cracked Specimens

The use of synthetic fibers in fiber-reinforced concretes (FRCs) is often avoided due to the mistrust of lower performance at changing temperatures. This work examines the effect of moderate temperatures on the flexural strengths of FRCs. Two types of polypropylene fibers were tested, and one steel fiber was employed as a reference. Three-point bending tests were carried out following an adapted methodology based on the standard EN 14651. This adapted procedure included an insulation system that allowed the assessment of FRC flexural behavior after being exposed for two months at temperatures of 5, 20, 35 and 50 °C. In addition, the interaction of temperature with a pre-cracked state was also analyzed. To do this, several specimens were pre-cracked to 0.5 mm after 28 days and conditioned in their respective temperature until testing. The findings suggest that this range of moderate temperatures did not degrade the behavior of FRCs to a great extent since the analysis of variances showed that temperature is not always a significant factor; however, it did have an influence on the pre-cracked specimens at 35 and 50 °C.

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Utilization of Dacite as Alternative Aggregate in Asphalt Mixture

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.509.209 ◽

2012 ◽

Vol 509 ◽

pp. 209-214

Author(s):

Shao Peng Wu ◽

Pan Pan ◽

Ming Yu Chen

Keyword(s):

Asphalt Mixture ◽

Asphalt Mixtures ◽

Major Objective ◽

Widespread Application ◽

Bending Tests ◽

Three Point Bending ◽

Large Numbers ◽

Asphalt Content ◽

The Cost ◽

Cost Of Construction

With the widespread application of asphalt mixture, current demand from transportation managers for construction and maintenance of their pavement network consumes large numbers of aggregates. If agencies excessively favor to some certain kinds of excellent aggregates, the cost of construction could be considerably expensive. The major objective of this study is to determine the feasibility of utilizing dacite in asphalt mixtures. By means of Marshall, freeze-thaw, rutting and three-point bending tests, the performances of dacite and basalt asphalt mixture are compared. The results of the testing illustrate that dacite asphalt mixture is more susceptible to gradation and asphalt content than basalt asphalt mixture. Meanwhile it is showed that the performances of dacite asphalt mixture can be improved greatly with the involvement of additives including active mineral powder and cement. Furthermore, it is validated that dacite can be used as alternative aggregate in asphalt mixture.

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