Compressive Strength of high Performance Fibers

1988 ◽  
Vol 134 ◽  
Author(s):  
Satish Kumar ◽  
T. E. Helminiak
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Performance ◽  
Tensile Modulus ◽  
Direct Result ◽  
Polymeric Fibers ◽  
Aerospace Applications ◽  
The Poor ◽  
Significant Research ◽  
Axial Compressive Strength

ABSTRACTSignificant research efforts have been carried out to improve the tensile modulus and tensile strength of high performance carbon and polymeric fibers. Experimental polymeric fibers (ordered polymer fibers) have been prepared with moduli >50 MPSI and tensile strength approaching one MPSI. However, the benefits of the above improvements in tensile properties for aerospace applications are limited because composites of these fibers have low axial compressive strength, which is a direct result of the poor axial fiber compressive strength. The poor axial fiber compressive strength has usually been attributed to the microfibrillar/fibrillar buckling. However, questions concerning the intrinsic limitations at the molecular level and the effects of intermolecular interactions are also considered important. Better understanding of these aspects will help in determining the theoretically achievable compressive strength and may aid in the development of higher compressive strength high performance fibers. These and other issues related to the compressive strength of high performance polymeric and carbon fibers are discussed in this paper.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

Carbon fiber reinforced tin-superconductor composites

1989 ◽  
Vol 4 (6) ◽  
pp. 1339-1346 ◽  
Author(s):  
C. T. Ho ◽  
D. D. L. Chung
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Tensile Modulus ◽  
Tensile Load ◽  
Tensile Fracture ◽  
Fiber Direction ◽  
Continuous Carbon Fiber

Unidirectional and continuous carbon fiber tin-matrix composites were used for the packaging of the high-temperature superconductor YBa2Cu3O7–δ by diffusion bonding at 170 °C and 500 psi. Tin served as the adhesive and to increase the ductility, the normal-state electrical conductivity, and the thermal conductivity. Carbon fibers served to increase the strength and the modulus, both in tension along the fiber direction and in compression perpendicular to the fiber layers, though they decreased the strength in compression along the fiber direction. Carbon fibers also served to increase the thermal conductivity and the thermal fatigue resistance. At 24 vol. % fibers, the tensile strength was approximately equal to the compressive strength perpendicular to the fiber layers. With further increase of the fiber content, the tensile strength exceeded the compressive strength perpendicular to the fiber layers, reaching 134 MPa at 31 vol. % fibers. For fiber contents less than 30 vol. %, the compressive ductility perpendicular to the fiber layers exceeded that of the plain superconductor. At 30 vol. % fibers, the tensile modulus reached 15 GPa at room temperature and 27 GPa at 77 K. The tensile load was essentially sustained by the carbon fibers and the superconducting behavior was maintained after tension almost to the point of tensile fracture. Neither Tc nor Jc was affected by the composite processing.

Development of High Performance Concrete Containing Admixture in Nuclear Power Plants

2013 ◽  
Vol 357-360 ◽  
pp. 1062-1065 ◽  
Author(s):  
Jeong Eun Kim ◽  
Wan Shin Park ◽  
Song Hui Yun ◽  
Do Gyeum Kim ◽  
Jea Myoung Noh
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Modulus Of Elasticity ◽  
Blast Furnace Slag ◽  
High Performance ◽  
Splitting Tensile Strength ◽  
Furnace Slag

This paper presents the results of an experimental study on the compressive strength, splitting tensile strength and modulus of elasticity characteristics of high performance concrete. These tests were carried out to evaluate the mechanical properties of HPC for up to 7 and 28 days. Mixtures were prepared with water to binder ratio of 0.40. Two mixtures were containing fly ash at 25%, silica fume at 5% cement replacement, respectively. Another mixture was contains blast furnace slag and fly ash at 25%. Three standard 100¥a200 cylinder specimens were prepared. HPC showed improvement in the compressive strength and splitting tensile strength when ordinary Portland cement was replaced with silica fume. Compare with specimens FA25 and BS25FA25, specimen SF5 showed much more modulus of elasticity. It shows that the use of the blast furnace slag of 25% and fly ash of 25% cement replacement has caused a small increase in compressive strength and splitting tensile strength and modulus of elasticity compared to the only use of fly ash of 25% at 28days. The results indicated that the use of blast furnace slag or silica fume provided the good performance compare to fly ash when the mechanical properties of the high performance concretes were taken into account.

Evaluation of Relations among Basic Mechanical Properties of Concrete with Machine-Made Sand

2011 ◽  
Vol 418-420 ◽  
pp. 441-444 ◽  
Author(s):  
Feng Lan Li ◽  
Yan Zeng ◽  
Chang Yong Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Rough Surface ◽  
Design Code ◽  
Ordinary Concrete ◽  
Axial Compressive Strength ◽  
Different Characteristics

Due to many different characteristics such as irregular polygon particle with pointed edges, rough surface and larger content of stone powder, machine-made sand has ignorable effects on the properties of concrete. As the basis for the design of concrete structures, the relations among the basic mechanical properties of concrete such as compressive strength, tensile strength, flexural strength and elastic modulus should be clearly understood. This paper summarizes the test data from the published references, and discusses the relations among these properties by statistical analyses compared with those of ordinary concrete. The results show that the axial compressive strength and the tensile strength can be prospected by the same formulas of ordinary concrete specified in current Chinese design code, but the prospected tensile strength should multiply a reducing coefficient when the strength grade of concrete is lower than C30. The elastic modulus of concrete with machine-made sand is larger than that of ordinary concrete, which should be prospect by the formula in this paper. Meanwhile, the formula of flexural strength is suggested.

Influence of Blast Furnace Slag on the Mechanical Properties of High Performance Concrete

2013 ◽  
Vol 634-638 ◽  
pp. 2716-2719
Author(s):  
Wan Shin Park ◽  
Sung Ho Cho ◽  
Song Hui Yun ◽  
Jeong Eun Kim ◽  
Do Gyeum Kim ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
High Performance ◽  
High Performance Concrete ◽  
Splitting Tensile Strength ◽  
International Standards ◽  
Binder Ratio ◽  
Furnace Slag

The characteristics of the compressive strength and splitting tensile strength according to replacement ratio of the blast furnace slag were found in this study. The blast furnace slag was utilizes as the concrete mix-material and then, these results were compared with the basis presented in the international standards. In this study, cylinder made of concrete with water/binder ratio 0.34 and blast furnace slag replacement rate of 10%, 30%, 50%, and 70% were prepared to measure the compressive strength and spiting tensile strength. Test results indicate that The 28 days and 91 days compressive strength is affected by blast furnace slag replacement except specimen BS30 and the splitting tensile strength in specimen BS series is slightly larger than that of OPC except specimen BS 30.

Experiment and Research on Mechanic Behavior of Concrete with Different Addition Amounts of Polypropylene Fibers

2012 ◽  
Vol 430-432 ◽  
pp. 1064-1067
Author(s):  
Yu Zhi Chen ◽  
Wei Hong Xuan ◽  
Xiao Hong Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Polypropylene Fiber ◽  
Polypropylene Fibers ◽  
Flexural Tensile Strength ◽  
Axial Compressive Strength ◽  
Low Dosage

The effect of the different addition amounts of polypropylene fibers on the basic mechanical properties of concrete were investigated in this paper. The results show that the flexural tensile strength of concrete changed slightly after adding low-dosage polypropylene fiber(0.04%～0.16%); Axial compressive strength and flexural tension modulus decreased, limiting flexural strain increased gradually with the amounts of fibers rising.

Experimental Study on the Axial Compressive Strength and Elastic Modulus of GHPFRCC

2013 ◽  
Vol 357-360 ◽  
pp. 1138-1141 ◽  
Author(s):  
Xiu Ling Li ◽  
Wang Juan
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
High Performance ◽  
Construction Material ◽  
Structure Design ◽  
Sustainable Construction ◽  
High Performance Fiber ◽  
Maintenance Decisions ◽  
Axial Compressive Strength ◽  
Pva Fiber

The sustainability of the construction material is increasingly coming to the forefront of the structure design and maintenance decisions. To address this, development of a new class of more sustainable construction material is needed, especially in China. This paper reports on the development of the green high-performance fiber-reinforced cementitious composites (GHPFRCC) with high volumes of fly ash and PVA fiber, and emphasizes the axial compressive strength and elastic modulus of GHPFRCC. Experimental results show that the prism axial compressive strength of GHPFRCC ranges from 15MPa to 40MPa. The elastic modulus of GHPFRCC is around 16-35GPa, typically lower than concrete.

Experimental Study on Workability and Strength of Green High Performance Concrete with High Volume Fly Ash

2013 ◽  
Vol 859 ◽  
pp. 52-55 ◽  
Author(s):  
Yong Qiang Ma
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
High Volume ◽  
Ash Content ◽  
Splitting Tensile Strength ◽  
Binder Ratio ◽  
Water Binder Ratio

A great deal of experiments have been carried out in this study to reveal the effect of the water-binder ratio and fly ash content on the workability and strengths of GHPC (green high performance concrete). The workability of GHPC was evaluated by slump and slump flow. The strengths include compressive strength and splitting tensile strength. The results indicate that the increase of water-binder ratio can improve the workability of GHPC, however the strengths of GHPC were decreased with the increase of water-binder ratio. When the fly ash content is lower than 40%, the increase in fly ash content has positive effect on workability of GHPC, while the workability begins to decrease after the fly ash content is more than 40%. The addition of fly ash in GHPC has adverse effect on the strengths, and there is a tendency of decrease in the compressive strength and splitting tensile strength of GHPC with the increase of fly ash content.

scholarly journals The Statistical Analysis of Relation between Compressive and Tensile/Flexural Strength of High Performance Concrete

2016 ◽  
Vol 62 (4) ◽  
pp. 95-108 ◽  
Author(s):  
M. Kępniak ◽  
P. Woyciechowski
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Influential Factors ◽  
Experimental Results ◽  
Model Code ◽  
Splitting Test ◽  
Model Code 2010

AbstractThis paper addresses the tensile and flexural strength of HPC (high performance concrete). The aim of the paper is to analyse the efficiency of models proposed in different codes. In particular, three design procedures from: the ACI 318 [1], Eurocode 2 [2] and the Model Code 2010 [3] are considered. The associations between design tensile strength of concrete obtained from these three codes and compressive strength are compared with experimental results of tensile strength and flexural strength by statistical tools. Experimental results of tensile strength were obtained in the splitting test. Based on this comparison, conclusions are drawn according to the fit between the design methods and the test data. The comparison shows that tensile strength and flexural strength of HPC depend on more influential factors and not only compressive strength.

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