Dowel action and shear strength contribution of high strength rebar embedded in ultra-high performance fiber reinforced concrete

2015 ◽  
Vol 83 ◽  
pp. 223-232 ◽  
Author(s):  
Jun Xia ◽  
Yulin Xiao ◽  
Kevin R. Mackie ◽  
Munaf Al-Ramahee ◽  
Amir Mirmiran
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Dowel Action ◽  
High Performance Fiber

scholarly journals Resistance of an Optimized Ultra-High Performance Fiber Reinforced Concrete to Projectile Impact

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 63
Author(s):  
Anna L. Mina ◽  
Michael F. Petrou ◽  
Konstantinos G. Trezos
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Depth Of Penetration ◽  
Projectile Impact ◽  
High Performance Fiber

The scope of this paper is to investigate the performance of ultra-high performance fiber reinforced concrete (UHPFRC) concrete slabs, under projectile impact. Mixture performance under impact loading was examined using bullets with 7.62 mm diameter and initial velocity 800 m/s. The UHPFRC, used in this study, consists of a combination of steel fibers of two lengths: 6 mm and 13 mm with the same diameter of 0.16 mm. Six composition mixtures were tested, four UHPFRC, one ultra-high performance concrete (UHPC), without steel fibers, and high strength concrete (HSC). Slabs with thicknesses of 15, 30, 50, and 70 mm were produced and subjected to real shotgun fire in the field. Penetration depth, material volume loss, and crater diameter were measured and analyzed. The test results show that the mixture with a combination of 3% 6 mm and 3% of 13 mm length of steel fibers exhibited the best resistance to projectile impact and only the slabs with 15 mm thickness had perforation. Empirical models that predict the depth of penetration were compared with the experimental results. This material can be used as an overlay to buildings or to construct small precast structures.

scholarly journals Implementation of Highly-Flowable Strain Hardening Fiber Reinforced Concrete in New RC Beam-Column Joints

2018 ◽  
Vol 147 ◽  
pp. 01003
Author(s):  
Wen-Cheng Liao ◽  
Wei-Ru Su
Keyword(s):  
Reinforced Concrete ◽  
Strain Hardening ◽  
Life Cycle Cost ◽  
High Performance ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Building Systems ◽  
Rc Building ◽  
High Performance Fiber

The purpose of New RC project was aimed to reduce the member sections and increase the available space of high rise buildings by using high strength concrete (f’c > 70 MPa) and high strength rebars (fy > 685 MPa). Material consumptions and member section sizes can be further reduced owing to the upgrade of strength. However, the nature of brittleness of high strength may also cause early cover spalling and other ductility issues. Addition of steel fibers is an alternative as transverse reinforcement. Highly flowable strain hardening fiber reinforced concrete (HF-SHFRC) has excellent workability in the fresh state and exhibits the strain-hardening and multiple cracking characteristics of high performance fiber reinforced cementitious composites (HPFRCC) in their hardened state. The objective of this study is to investigate the feasibility of implementing HF-SHFRC in New RC building systems, particularly for beam-column joints as an alternative of transverse reinforcements. Four full-scale exterior beam-column joints, including two specimens with intensive transverse reinforcements and two specimens made of HF-SHFRC without any stirrup, are tested. Test results show that the HF-SHFRC specimens perform as well as specimens with intensive transverse reinforcements regarding failure mode, ductility, energy dissipation and crack width control. Integration of New RC building systems and HF-SHFRC can assuring construction qualities and further diminish labor work and give infrastructure longer service life, and eventually lower the life-cycle cost.

scholarly journals Performance Comparison between Densified and Undensified Silica Fume in Ultra-High Performance Fiber-Reinforced Concrete

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3901 ◽  
Author(s):  
Sung-Hoon Kang ◽  
Sung-Gul Hong ◽  
Juhyuk Moon
Keyword(s):  
Reinforced Concrete ◽  
Silica Fume ◽  
High Performance ◽  
High Strength ◽  
Performance Comparison ◽  
Fiber Reinforced Concrete ◽  
Hydration Reaction ◽  
Fiber Reinforced ◽  
Dust Generation ◽  
High Performance Fiber

Silica fume (SF) is a key ingredient in the production of ultra-high performance fiber-reinforced concrete (UHPFRC). The use of undensified SF may have an advantage in the dispersion efficiency inside cement-based materials, but it also carries a practical burden such as high material costs and fine dust generation in the workplace. This study reports that a high strength of 200 MPa can be achieved by using densified SF in UHPFRC with Portland limestone cement. Additionally, it was experimentally confirmed that there was no difference between densified and undensified SFs in terms of workability, compressive and flexural tensile strengths, and hydration reaction of the concrete, regardless of heat treatment, because of a unique mix proportion as well as mixing method for dispersing agglomerated SF particles. It was experimentally validated that the densified SF can be used for both precast and field casting UHPFRCs with economic and practical benefits and without negative effects on the material performance of the UHPFRC.

EXPERIENCE IN USING ULTRA HIGH PERFORMANCE FIBER REINFORCED CONCRETE ELEMENTS

2021 ◽  
pp. 41-50
Author(s):  
Maxim MARCHENKO ◽  
Igor CHILIN ◽  
Nikita SELYUTIN
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
Economic Effect ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Common Solution ◽  
Flexural Tensile Strength ◽  
High Performance Fiber

The article presents examples of the use of ultra-high performance fiber reinforced concrete for load-bearing structures in Russia. Using this material with limits of compressive strength 150 MPa, flexural tensile strength 21 MPa, tensile strength 8.5 MPa, external post-tensioned structures of bridges and tanks are made instead of common solution with the steel anchors. Full-scale tests of anchors were carried out, which did not reveal signs of deformations and destruction of elements during the tension of strands, at the level of design and ultimate loads - before strands rupture. It was concluded that it is advisable to replace steel anchors with anchors from the material, which, with high strength characteristics, has ultra-low permeability and high frost resistance corresponding to the F21000 class. The estimated economic effect of such a replacement is determined by the reduced cost of these elements of structures made of ultra-high performance fiber reinforced concrete in comparison with steel.

Shear Strength of Dry and Epoxy Joints for Ultra-High-Performance Fiber-Reinforced Concrete

2020 ◽  
Vol 117 (1) ◽  
Author(s):  
Balamurugan A. Gopal ◽  
Farzad Hejazi ◽  
Milad Hafezolghorani ◽  
Yen Lei Voo
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
High Performance Fiber

scholarly journals Effect of confining pressure on shear resistance of ultra-high-performance fiber reinforced concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 108-115
Author(s):  
Ngo Tri Thuong
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
Steel Fiber ◽  
Confining Pressure ◽  
Shear Resistance ◽  
Fiber Reinforced Concrete ◽  
Test Method ◽  
Fiber Reinforced ◽  
High Performance Fiber

Effect of confining pressure on the shear resistance of ultra-high-performance fiber-reinforced concrete (UHPFRCs), containing 1.5% volume content (1.5 vol.-%) of short smooth steel fiber (SS, l = 13, d = 0.2 mm) and long smooth steel fiber (LS, l = 30, d = 0.3 mm), was investigated using a new shear test method. Three levels of confining pressure were generated and maintained to the longitudinal axis of the specimen prior shear loading was applied. The test results exhibited that the shear strength of UHPFRCs was obviously sensitive to the confining pressure: the higher confining pressure produced higher shear strength. UHPFRC reinforced with 1.5 vol.-% long smooth steel fiber exhibited higher shear resistance than those reinforced with short smooth steel fiber, regardless of confining pressure levels. The confined shear strength could be expressed as an empirical function of unconfined shear strength, confining pressure, and tensile strength of UHPFRCs. Keywords: UHPFRCs, shear resistance; confining pressure effect; smooth fiber.

scholarly journals The Performance Evaluation of Circular Flange Bolted Connection in Ultra High Performance Fiber Reinforced Concrete Segmented Communication Tower

2019 ◽  
Author(s):  
Doaa Talib Hashim ◽  
Farzad Hejazi ◽  
Mohd Saleh Jaafar ◽  
Voo Yen Lai
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Fem Analysis ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Failure Behavior ◽  
Fiber Reinforced ◽  
Bolted Connection ◽  
High Performance Fiber ◽  
Steel Bolts

This study herein presents investigations about behavior of circular flange bolted connection (CFBC) in ultra high performance fiber reinforced concrete (UHPFRC) hollow segmented communication tower subjected to lateral dynamic load. The CFBC consists of two flanged concrete, cast together with the structural segment tubes and then connected using steel bolts. The paper is illustrated with CFBC joint of 500mm flange thicknesses, and 8M25 high strength steel bolts coming from a typical real design tower. For this purpose, the full scale CFBC joints for communication tower are made from Ultra High Performance Fiber Reinforced Concrete (UHPFRC). The connection was cast and experimentally tested by applying cyclic lateral load using dynamic actuator. The lateral strength and stiffness resistance of the UHPFRC CFB connections were evaluated in this study. Besides, a rigorous FEM analysis was executed in order to evaluate the performance of CFBC in the communication tower by investigating the mechanism of force transfer, load bearing capacity as well as failure behavior of the circular flange bolted connection (CFBC) under lateral cycling loading. The experimental and numerical analysis results showed the ability of UHPFRC circular bolted connection to resist the applied lateral loads. In addition, the considered model revealed that for joints under tension, bolts were seriously not subjected to bending moments which is due to the prying effect. This was made possible by the provision of adequate flange thickness and strength of the UHPFRC material.

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