Dynamic Load Effects of PVA Tail Sand Cement Base Composite Materials

2014 ◽  
Vol 518 ◽  
pp. 66-70 ◽  
Author(s):  
Wen Bo Bao ◽  
Shao Feng Zhang ◽  
Gao Hao Di ◽  
Wei Wei Ji ◽  
Li Hui Qu
Keyword(s):  
Composite Materials ◽  
Volume Content ◽  
Dynamic Load ◽  
Plate Thickness ◽  
Replacement Rate ◽  
Fiber Volume ◽  
Mechanics Performance ◽  
Load Effects ◽  
Base Composite ◽  
Pva Fiber

This paper studies that dynamic load affects mechanical properties of materials about composite tail ore different replacement rate, different PVA fiber volume content and different plate thickness. The phenomenon of the tests and results showed that:1) PVA tailings cement-based composite materials has low damage, strong integrity and strong energy dissipation under dynamic loading. 2) When the volume content is 2%, material resistance effect is best. 3) The study proves that 30 mm plate have good ductility and Size effect influence the material mechanics performance. 4) PVA tailings cement-based composite materials under dynamic loads ,as tailings content increases the performance indicators reduced. So the engineering applications recommended replacement rate of the tailings is 50%.

scholarly journals Performance Test and Microstructure of Modified PVC Aggregate-Hybrid Fiber Reinforced Engineering Cementitious Composite (ECC)

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1856
Author(s):  
Shi Hu ◽  
Haibing Cai ◽  
Rongbao Hong ◽  
Mengkai Li ◽  
Fangxing Yao
Keyword(s):  
Fly Ash ◽  
Water Absorption ◽  
Volume Content ◽  
Performance Test ◽  
Compression Tests ◽  
Hybrid Fiber ◽  
Fiber Volume ◽  
Impact Failure ◽  
Failure Energy ◽  
Pva Fiber

This study aims to solve the problems of the high cost, heavy pollution and poor performance of traditional engineered cementitious composites (ECC) by adding modified Polyvinyl chloride (PVC) aggregate, Polypropylene (PP)–Polyvinyl alcohol (PVA) hybrid fiber and large amount of fly ash. The PVC aggregate is modified by pre-coating silica fume with a PP fiber volume content of 0.5%, PVA fiber volume contents of 1%, 1.5%, and 2%, PVC aggregate contents of 10%, 20%, and 30%, and fly ash volume content of 69%. Different properties and microstructures were studied by carrying out cube compression tests, splitting tensile tests, water absorption tests, drop hammer impact tests, scanning electron microscopy and nuclear magnetic resonance tests. According to the test results, under the same content of PVC aggregate, the use of modified PVC aggregate can, not only effectively avoid the decrease in strength and increase of water absorption, but also improve brittleness and impact failure energy. Regardless of the kind and content of fiber, the compressive strength and brittleness will decrease, while the splitting tensile strength, water absorption, and impact failure energy will increase. After adding 0.5% PP and 1.5% PVA fiber, the performance is ordinary and a negative mixing effect occurs. As more modified PVC aggregate is added, the strength of the ECC concrete with PP–PVA hybrid fiber and modified PVC aggregate added slowly decrease, while the water absorption and impact failure energy increase. Based on a comprehensive analysis of the test data, the reinforcement method of adding 1.5% PVA-0.5% PP hybrid fiber-30% modified PVC aggregate is superior to adding 1.5% PVA fiber, but slightly inferior to adding 2% PVA fiber. This study argues that the reinforcement method is of great significance for the promotion and application of ECC.

Wear-resistant bronze-base composite materials produced by electric-discharge sintering

1980 ◽  
Vol 19 (9) ◽  
pp. 591-592
Author(s):  
A. I. Raichenko ◽  
L. V. Zabolotnyi ◽  
O. N. Ryabinina ◽  
V. V. Pushkarev
Keyword(s):  
Composite Materials ◽  
Electric Discharge ◽  
Wear Resistant ◽  
Base Composite ◽  
Electric Discharge Sintering

Modeling The Microwave Frequency Dielectric Properties of Thermoplastic Composite Materials

1992 ◽  
Vol 269 ◽  
Author(s):  
Mitchell L. Jackson ◽  
Curtis H. Stern
Keyword(s):  
Composite Materials ◽  
Dielectric Properties ◽  
Volume Fraction ◽  
Perturbation Technique ◽  
Resonant Cavity ◽  
Microwave Frequency ◽  
Thermoplastic Composite ◽  
Fiber Volume ◽  
Thermoplastic Matrix ◽  
Rotation Procedure

ABSTRACTMixture models were studied in an effort to predict the microwave frequency permittivities of unidirectional-fiber-reinforced thermoplastic-matrix composite materials as a function of fiber volume fraction, fiber orientation relative to the electric field, and temperature. The permittivities of the constituent fiber and plastic materials were measured using a resonant cavity perturbation technique at 9.4 GHz and at 2.45 GHz. The permittivities of the composite specimens were measured using a reflection cavity technique at 9.4 GHz and at 2.45 GHz. Simple “rule-of-mixtures” models that use the fiber and plastic permittivities have been found to approximate the complex dielectric properties of the composite for varied fiber volume fractions. The permittivities of oriented composites were modeled using a tensor rotation procedure. Composite permittivities were modeled with temperature up to the glass transition temperature of the thermoplastic matrix.

scholarly journals Influence of the Fiber Volume Content on the Durability-Related Properties of Polypropylene-Fiber-Reinforced Concrete

2020 ◽  
Vol 12 (2) ◽  
pp. 549
Author(s):  
Chenfei Wang ◽  
Zixiong Guo ◽  
Ditao Niu
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Volume Content ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Freeze Thaw ◽  
Chloride Environment ◽  
Polypropylene Fiber Reinforced Concrete

Polypropylene-fiber-reinforced concrete impacts the early shrinkage during the plastic stage of concrete, and the fiber volume content influences the durability-related properties of concrete. The purpose of this paper was to investigate the influence of fiber volume content on the mechanical properties, durability, and chloride ion penetration of polypropylene-fiber-reinforced concrete in a chloride environment. Tests were carried out on cubes and cylinders of polypropylene-fiber-reinforced concrete with polypropylene fiber contents ranging from 0% to 0.5%. Extensive data from flexural strength testing, dry–wet testing, deicer frost testing, and chloride penetration testing were recorded and analyzed. The test results show that the addition of the fiber improves the failure form of the concrete specimens, and 0.1% fiber content maximizes the compactness of the concrete. The flexural strength of specimen C2 with 0.1% fiber shows the highest strength obtained herein after freeze–thaw cycling, and the water absorption of specimen C2 is also the lowest after dry–wet cycling. The results also indicate that increasing the fiber volume content improves the freeze–thaw resistance of the concrete in a chloride environment. Chlorine ions migrate with the moisture during dry–wet and freeze–thaw cycling. The chlorine ion diffusion coefficient (Dcl) increases with increasing fiber content, except for that of specimen C2 in a chloride environment. The Dcl during freeze–thaw cycling is much higher than that during dry–wet cycling.

scholarly journals Influence of polyvinyl alcohol fiber and fly ash content on compressive creep properties of high ductility cementitious composites

2021 ◽  
Vol 272 ◽  
pp. 02014
Author(s):  
Bo Chen ◽  
Liping Guo ◽  
Lihui Zhang ◽  
Wenxiao Zhang ◽  
Yin Bai ◽  
...  
Keyword(s):  
Fly Ash ◽  
Polyvinyl Alcohol ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Ash Content ◽  
Creep Model ◽  
High Ductility ◽  
Fiber Volume ◽  
Leading Role ◽  
Pva Fiber

The influence of polyvinyl alcohol (PVA) fiber volume fraction and fly ash content on the creep behavior of high ductility cementitious composites (HDCC) under compression was investigated. For this investigation, the creep behavior of four HDCC groups with cube compressive strength of 30–50 MPa, PVA fiber volume fraction of 1.5% and 2.0%, and fly ash content of 60% and 80% at 7 d and 28 d loading periods, respectively, were evaluated. A compressive creep model, which reflects the loading age and holding time, was established. The results revealed that when the load was applied at 7 d and 28 d, and then maintained for 245 d, the specific creep of HDCC ranged from 95×10-6/ MPa to 165×10-6/ MPa and from 59×10-6/ MPa to 135 × 10−6/ MPa, respectively. The corresponding creep coefficients ranged from 1.48 to 2.25 and from 1.10 to 1.94, respectively. The PVA fiber volume fraction and fly ash content were the main factors affecting the specific creep of HDCC, which increased with increasing fiber fraction and fly ash content. Under short-term loading, the fiber volume fraction played a leading role in the specific creep, and the fly ash content played the leading role during long-term loading. Furthermore, the specific creep and creep coefficient decreased significantly with increasing loading age. The classical creep model described by a power exponent function is suitable for HDCC.

Toughness of ECC Evaluated by Nominal Fracture Energy

2012 ◽  
Vol 238 ◽  
pp. 57-60 ◽  
Author(s):  
Shu Ling Gao ◽  
Wei Shao ◽  
Jin Li Qiao ◽  
Ling Wang
Keyword(s):  
Glass Fiber ◽  
Fracture Energy ◽  
Steel Fiber ◽  
Volume Ratio ◽  
Fiber Glass ◽  
Fiber Volume ◽  
High Durability ◽  
The Matrix ◽  
Pva Fiber ◽  
Very High

ECC (Engineered Cementitious Composites) has ultra-high toughness and can be used in the zone needing the ultra-high tensile strain and very high durability. In order to investigate the toughness of ECC, the normal fracture energy GFis calculated and compared with ordinary concrete. The influence of the matrix (fly ash, silicon fume), the fiber (glass fiber, steel fiber and PVA fiber) and the fiber volume ratio on the GFof ECC are analyzed. The research indicates that silicon fume and glass fiber, steel fiber are all not able to be used in ECC. But flash ash and PVA fiber are very suit for using in ECC, the toughness of ECC increases with the increase of their content.

Co-Integration-Based Compensation Technique for Dynamic Load Effects on the Electro-mechanical Impedance Method

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Xiaoluo Jie ◽  
Wenzhong Qu ◽  
Li Xiao ◽  
Ye Lu
Keyword(s):  
Dynamic Load ◽  
Mechanical Impedance ◽  
Piezoelectric Transducers ◽  
Impedance Method ◽  
Operational Conditions ◽  
Load Effects ◽  
Compensation Technique ◽  
Aluminum Beam ◽  
Stress Variations ◽  
Stationary Behavior

Abstract The electro-mechanical (EM) admittance signals acquired from piezoelectric transducers (PZT) surface bonded to the host structure are often used for structural health monitoring (SHM). However, it is well known that the method is susceptible to contamination from environmental and operational conditions. This paper introduces a co-integration method to remove dynamic load effects from electro-mechanical admittance data. The proposed method is based on the concept of co-integration that is partially built on the analysis of the non-stationary behavior of time series. Instead of directly using admittance signatures of PZT for damage detection, the analysis of the co-integrated residual obtained from the co-integration procedure of EM admittance responses and the resonant peaks frequency of the real part of admittance (conductance) are chosen as co-integrated variables. The experiments of aluminum beam bolt loosening identification, which is under dynamic stress, were carried out to verify the effectiveness of the proposed method. The results showed that the method can isolate damage-sensitive features from stress variations, so as to successfully detect the existence of damage.

scholarly journals Orthogonal Analysis on Mechanical Properties of Basalt–Polypropylene Fiber Mortar

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2937
Author(s):  
Huimin Chen ◽  
Chunyan Xie ◽  
Chao Fu ◽  
Jing Liu ◽  
Xiuli Wei ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Volume Content ◽  
Fiber Length ◽  
Content Volume ◽  
Polypropylene Fiber ◽  
Basalt Fiber ◽  
Test Method ◽  
Test Results ◽  
Fiber Volume

Orthogonal test method was applied to analyze the strength properties of basalt-polypropylene mortar. The effect of basalt fiber length, polypropylene fiber length, basalt fiber volume content and polypropylene fiber volume content on the 28 d cube compressive strength and flexural strength were investigated. Test results show that comparing with flexural strength, the influence of basalt fiber length and polypropylene fiber length on compressive strength of mortar was greater than on flexural strength. The length of polypropylene fibers contributes the highest to the flexural strength. The effect of basalt fiber on mortar strength is the largest with 6 mm length and 4% content. Polypropylene fiber length has the greatest influence on the compressive strength of fiber mortar, followed by basalt fiber volume content. Volume content of polypropylene fiber has the greatest influence on flexural strength of fiber mortar, followed by polypropylene fiber length. According to the scoring of the efficacy coefficient method, the best ratio combination for compressive and flexural strength was the basalt fiber length of 9 mm, polypropylene fiber length of 6 mm, basalt fiber volume content of 4% and polypropylene fiber volume content of 4%. Compared with the blank samples, the 28 d compressive strength and 28 d flexural strength of the cement mortar samples were increased by 27.4% and 49% respectively. According to the test results, the properties of the fiber were analyzed and evaluated and the mechanism of fiber action and fiber microstructure were analyzed.

Mechanics of Natural Composites

1990 ◽  
Vol 218 ◽  
Author(s):  
Joseph E. Saliba ◽  
Rebecca C. Schiavone ◽  
Stephen L. Gunderson ◽  
Denise G. Taylor
Keyword(s):  
Composite Materials ◽  
Modulus Of Elasticity ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Structural Response ◽  
Sensitivity Study ◽  
Fiber Volume ◽  
Fiber Size ◽  
Natural Composites ◽  
As Stress

AbstractThis study was initiated to investigate the structural response of the bessbeetle to determine potential advantageous ramifications and effects on the optimization of synthetic composite materials. The result of the micromechanics sensitivity study of various parameters are presented. Variables such as fiber size and shape, fiber volume fraction, ratio of modulus of elasticity of fiber over matrix, are changed one variable at a time, and the response quantities such as stress and tranverse modulus are presented.

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