scholarly journals Utilization of Local Ingredients for the Production of High-Early-Strength Engineered Cementitious Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Hanwen Deng
Keyword(s):  
High Performance ◽  
High Strength ◽  
Bending Test ◽  
Cementitious Composites ◽  
Chinese Market ◽  
The Matrix ◽  
High Performance Fiber ◽  
Early Strength ◽  
Direct Tensile ◽  
Direct Tensile Test

The rapid repair and retrofitting of existing transportation infrastructure requires dimensional stability and ductile repair material that can obtain sufficiently high strength in a few hours to accommodate the large loading and deformation at an early age. Engineering cementitious composites (ECCs) is a class representative of the new generation of high-performance fiber-reinforced cement-based composites (HPFRCC) with medium fiber content. The unique properties of tremendous ductility and tight multiple crack behavior indicate that ECC can be used as an effective retrofit material. The wide application of this material in China will require the use of all local ingredients. In this study, based on Chinese domestic ingredients, including matrix materials and all fibers, high-early-strength ECC (HES-ECC) was designed under the guidance of strain-hardening criterion of ECC. The matrix properties and fiber/matrix interfacial micromechanics properties were obtained from three-point-bending test and single-fiber pullout test. The mechanical properties of HES-ECC were achieved by direct tensile test. The experimental results show that HES-ECC was successfully developed by using all Chinese materials. When using the domestic PVA fiber at 2%, the strength requirement can be achieved but only a low ductility. When using the domestic PE fiber at 0.8%, the strength and deformation requirement both can be obtained. The HES-ECC developed in this study exhibited compressive strength of more than 25 MPa within 6 hours, and an ultimate tensile strength of 5-6 MPa and tensile strain capacity of 3-4% after 60 days. Moreover, the cost of using domestic fiber can be largely reduced compared with using imported fiber, up to 70%; it is beneficial to the promotion of these high-early-strength ECCs in the Chinese market.

Performance of Low Modulus Fibers in Engineered Cementitious Composites (ECCs): Flexural Strength and Pull out Resistance

2013 ◽  
Vol 687 ◽  
pp. 495-501 ◽  
Author(s):  
Mana Halvaei ◽  
Masoud Jamshidi ◽  
Masoud Latifi ◽  
Zahra Behdouj
Keyword(s):  
Flexural Strength ◽  
High Performance ◽  
Cementitious Materials ◽  
Cementitious Composites ◽  
Pull Out ◽  
The Matrix ◽  
High Performance Fiber ◽  
Low Modulus ◽  
New Generation ◽  
Fiber Reinforced Cementitious Composites

Cement based materials are brittle in nature. Fibers have been used to improve flexural/tensile behaviors of the cementitious materials from one hundred years ago. Recently, a new generation of high performance fiber reinforced cementitious composites (HPFRCCs) has been introduced by Professor V.C. Li which was called Engineered Cementitious Composite (ECC). ECC showed incredible flexural and tensile strengths as it was called as flexible concrete by some researchers. Usually, high modulus fibers have been used in ECCs as reinforcement. In this research, homemade low modulus fibers (acrylic, nylon 66 and polypropylene) were used as reinforcement in ECC. Flexural strength test were performed on the ECC sheets. Also, Pull out test was performed to determine adhesion energy and toughness between the fibers and the matrix. It was found that low modulus fibers caused lower flexural strength and bonding to matrix than PVA fibers. However, they were found as suitable fibers for products with good cost-quality balance especially for construction purposes.

Influence of Hybrid Steel Fiber Addition on Direct Tensile Behavior of UHPC

2016 ◽  
Vol 713 ◽  
pp. 270-272
Author(s):  
Seung Hun Park ◽  
Kyung Taek Koh ◽  
Gum Sung Ryu ◽  
Gi Hong An ◽  
Nam Kon Lee
Keyword(s):  
High Performance ◽  
Steel Fiber ◽  
Absorption Capacity ◽  
Tensile Behavior ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Energy Absorption Capacity ◽  
High Performance Fiber ◽  
Direct Tensile ◽  
Direct Tensile Test

This paper examines the direct tensile behavior of ultra high performance fiber reinforced concrete (UHPFRC) according to the addition of hybrid-type steel fibers with different lengths and diameters but identical aspect ratio. Two types of steel fibers that are MS fiber with length of 20 mm and diameter of 0.2 mm and LS fiber with length of 22 mm and diameter of 0.22 mm are adopted and admixed together with different proportions to give three series of mixes (MS10LS05, MS075LS075, MS05LS10). Direct tensile test is conducted on specimens using each of the considered mixes and notched on both sides. The results show that the tensile strength and the energy absorption capacity of UHPFRC tend to increase with larger proportions of relatively long steel fibers.

scholarly journals Influence of Secondary Reinforcement on Behaviour of Corbels with Various Types of High-Performance Fiber-Reinforced Cementitious Composites

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4159 ◽  
Author(s):  
Nasuha Md Zin ◽  
Amin Al-Fakih ◽  
Ehsan Nikbakht ◽  
Wee Teo ◽  
Mahmoud Anwar Gad
Keyword(s):  
High Performance ◽  
Load Capacity ◽  
Secondary Reinforcement ◽  
Bending Test ◽  
Cementitious Composites ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
High Performance Fiber ◽  
Fiber Reinforced Cementitious Composites

An experimental study is conducted to determine the influence of secondary reinforcement on the behaviour of corbels fabricated with three different types of high-performance fiber-reinforced cementitious composites, including engineered cementitious concrete (ECC); high-performance steel fiber-reinforced composite (HPSFRC); and hybrid fiber-reinforced composite (HyFRC). Two shear span-to-depth ratios (a/d = 0.75 and 1.0) are explored. The mechanical properties of the composites in terms of tensile, compressive, and flexural strengths are investigated. Next, the structural behaviour of the high-performance cementitious composite corbels in terms of ultimate load capacity, ductility, and failure modes under the three-point bending test are investigated. The secondary reinforcement is proven to significantly affect stiffness and ultimately load capacity of all three high-performance composite corbels with an aspect ratio of 0.75. However, the secondary reinforcement was more impactful for the HPSFRC corbels, with 51% increase of ultimate strength. Moreover, in terms of damage, fewer cracks occurred in ECC corbels. HPSFRC corbels displayed the highest level of ductility and deformation capacity compared to the other specimens. The results were comparatively analyzed against the predicted results using truss and plastic truss models which provided relatively reliable shear strength.

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.

C80 Early Strength Micro Expansion of Steel Tube Reinforced Concrete Research

2015 ◽  
Vol 1119 ◽  
pp. 752-755
Author(s):  
Chang Zheng Sun ◽  
Zheng Wang
Keyword(s):  
High Performance ◽  
Raw Materials ◽  
Influence Factors ◽  
High Strength ◽  
Steel Tube ◽  
Strength Analysis ◽  
Self Compacting Concrete ◽  
Mix Proportion ◽  
Early Strength ◽  
Working Performance

Optimization of mix proportion parameter ，Using ordinary raw materials makes a C80 high performance self-compacting concrete;By joining a homemade perceptual expansion agent, significantly improve the early strength of concrete and effective to solve the high strength of self-compacting concrete caused by gelled material consumption big contraction;Further study on the working performance of high-strength self-compacting concrete, age strength, analysis the influence factors of concrete are discussed.

Direct tension-dependent flexural behavior of ultra-high-performance fiber-reinforced concretes

2017 ◽  
Vol 52 (2) ◽  
pp. 121-134 ◽  
Author(s):  
Duy-Liem Nguyen ◽  
Duc-Kien Thai ◽  
Dong-Joo Kim
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Tensile Strain ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Tensile Response ◽  
High Performance Fiber ◽  
The Moment ◽  
Direct Tensile ◽  
Flexural Resistance

This research investigated the effects of direct tensile response on the flexural resistance of ultra-high-performance fiber-reinforced concretes by performing sectional analysis. The correlations between direct tensile and flexural response of ultra-high-performance fiber-reinforced concretes were investigated in detail for the development of a design code of ultra-high-performance fiber-reinforced concrete flexural members as follows: (1) the tensile resistance of ultra-high-performance fiber-reinforced concretes right after first-cracking in tension should be higher than one-third of the first-cracking strength to obtain the deflection-hardening if the ultra-high-performance fiber-reinforced concretes show tensile strain-softening response; (2) the equivalent bottom strain of flexural member at the modulus of rupture is always higher than the strain capacity of ultra-high-performance fiber-reinforced concretes in tension; (3) the softening part in the direct tensile response of ultra-high-performance fiber-reinforced concretes significantly affects their flexural resistance; and (4) the moment resistance of ultra-high-performance fiber-reinforced concrete girders is more significantly influenced by the post-cracking tensile strength rather than the tensile strain capacity. Moreover, the size and geometry effects should be carefully considered in predicting the moment capacity of ultra-high-performance fiber-reinforced concrete beams.

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