Development of High Performance Fiber Reinforced Composite with Negative Thermal Expansion Property

2008 ◽  
Vol 47-50 ◽  
pp. 89-92
Author(s):  
Hua Yang ◽  
Qing Qing Ni ◽  
Atsuhiko Yamanaka ◽  
Toshiaki Natsuki
Keyword(s):  
Thermal Expansion ◽  
High Performance ◽  
Negative Thermal Expansion ◽  
High Strength ◽  
Fiber Reinforced ◽  
Thermal Expansion Property ◽  
Expansion Property ◽  
Polyethylene Fiber ◽  
High Performance Fiber ◽  
Almost All

There are exists positive thermal expansion property for almost all materials. However, in many cases, the material property with negative thermal expansion is requested for engineering applications. This work is to develop high performance fiber-reinforced composites with negative thermal expansion by using high strength polyethylene fiber Dyneema®, high strength PBO fiber ZYLON®, aramid fiber Technora ® and carbon fibers.

Electromagnetic Shielding Properties of Super Fiber-Reinforced Composites

2010 ◽  
Vol 123-125 ◽  
pp. 65-68 ◽  
Author(s):  
Hua Yang ◽  
Atsuhiko Yamanaka ◽  
Qing Qing Ni
Keyword(s):  
High Performance ◽  
High Strength ◽  
Electromagnetic Shielding ◽  
Fiber Reinforced Composites ◽  
Shielding Effect ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Polyethylene Fiber ◽  
High Performance Fiber ◽  
Shielding Properties

Electromagnetic shielding effect material is needed because electronic devices suffer electromagnetic interference. Otherwise, in many engineering designs such as antenna fairings, sonar cover and stealth aircraft, materials with good electromagnetic penetration are desired. High performance fiber-reinforced composites have high specific strength and mechanical properties, and there is therefore a need to develop an electronics enclosure with optimum shielding by using a combination of particular fiber reinforcements and a polymer matrix. This paper describes the development of high-performance fiber-reinforced composites that use four high strength fibers (super fibers), Dyneema SK60 (an ultra-high molecular weight polyethylene fiber), Zylon HM (poly-p-phenylenebenzobisoxazole fiber), Technora T-241J (aramid fiber) and Torayca T800HB (carbon fiber). These super fibers were fabricated by compression molding and their shielding effectiveness (SE) was tested. The results showed that the newly developed Dyneema fiber, Zylon fiber and Technora fiber composites exhibited low electromagnetic shielding properties of 1.3~2.3 dB at a frequency of 0.5~18 GHz. Furthermore, the Torayca fiber composite has high electromagnetic shielding properties of 10.2~20.7 dB at the same frequency. It is expected that these high-strength composites with optimum SE can be obtained by controlling the electromagnetic shielding properties from hybrid multi-fiber structures.

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.

Enhanced Negative Thermal Expansion Property Deduced by the Breaks of Superstructure

2021 ◽  
Vol 13 (4) ◽  
pp. 556-562
Author(s):  
Niu Zhang ◽  
Ming-Yi Wu ◽  
Ya-Ming Liu ◽  
Meng-Jie Yang ◽  
Ming-Ju Chao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Expansion ◽  
Wide Temperature Range ◽  
Potential Application ◽  
Negative Thermal Expansion ◽  
Thermal Expansion Property ◽  
Expansion Property ◽  
Good Potential ◽  
Nested Structure

The HfV2O7/HfMo2O8 composite were prepared in situ. The phase, structure and thermal expansion property were analyzed. The results indicate the composite consist of cubic HfV2O7 and hexagonal HfMo2O8. The two types of structures were coexisted and mixed uniformly, and interacted with each other. The mutual nested structure suppressed the formation of 3×3×3 superstructure in HfV2O7 (RT) introduced by the reaction in situ. The promoted coupled rotation of quasi-rigid polyhedron units could enhance the negative thermal expansion (NTE) property. The HfV2O7/HfMo2O8 composite exhibits excellent NTE property from 250 to 673 K (at least) with CTE -3.09 × 10-6 K-1. The good NTE property and thermal stability over a wide temperature range, especially near the RT range, bring a good potential application in designing zero thermal expansion materials.

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.

Preparation and Negative Thermal Expansion Property of ZrWMoO8

2010 ◽  
Vol 177 ◽  
pp. 245-248
Author(s):  
Juan Yang ◽  
Qin Qin Liu ◽  
Chuang Liang Zang ◽  
Xiao Nong Cheng
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Mechanical Analysis ◽  
Cell Parameters ◽  
Thermal Expansion Property ◽  
In Situ Xrd ◽  
Structure And Morphology ◽  
Expansion Property ◽  
Different Temperatures

Negative thermal expansion (NTE) material ZrWMoO8 was prepared by hydrothermal method. The phase structure and morphology of the obtained precursor and final product were examined by XRD and SEM, respectively. To study its negative thermal expansion property, two methods were utilized. One is based on the in-situ XRD results and the thermal expansion coefficient (CTE) was calculated by the cell parameters obtained at different temperatures. Another is based on the thermo-mechanical analysis (TMA) and the CTE was calculated by the length of ZrWMoO8 bar at different temperatures. The differences between these two methods were also discussed.

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.

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