Influence of Fiber Type on Concrete Flexural Toughness

2011 ◽  
Vol 287-290 ◽  
pp. 1179-1183
Author(s):  
Jian Guo Han ◽  
Pei Yu Yan
Keyword(s):  
Steel Fiber ◽  
Fiber Type ◽  
Concrete Strength ◽  
Plain Concrete ◽  
Concrete Specimen ◽  
Ratio Method ◽  
Flexural Toughness ◽  
The Common ◽  
Better Than ◽  
Curing Age

Using PCER (post-crack energy ratio) method and plain concrete specimen as reference, the flexural toughness enhancing ability of propylene spinning fiber, propylene monofilament fiber and end-deformed steel fiber was studied. Experiment results show that under the common engineering dosage, the flexural toughness enhancing ability of end-deformed steel fiber is far more outstanding than propylene fibers, and comparing with each other, the flexural toughness enhancing ability of propylene spinning fiber is better than propylene monofilament fiber. As far as one type of fiber is concerned, under the same dosage, along with the enhancement of concrete strength grade, the flexural toughness enhancing ability tends to decrease. Meanwhile, along with enhancement of curing age, the flexural toughness enhancing ability tends to decrease also.

Evaluating Plain Concrete Flexural Toughness Using PCER Method

2011 ◽  
Vol 287-290 ◽  
pp. 1184-1188
Author(s):  
Jian Guo Han ◽  
Pei Yu Yan ◽  
Gang Ling Li
Keyword(s):  
Plain Concrete ◽  
Energy Ratio ◽  
Ratio Method ◽  
K Value ◽  
Flexural Toughness ◽  
Strength Grade ◽  
Curing Age ◽  
Changing Tendency

Using PCER (post-crack energy ratio) method, the influence of strength grade and curing age on flexural toughness of plain concrete were analyzed. Results show that along with the increase of strength grade and curing age, the flexural toughness of plain concrete decrease; and along with the increase of the K value used in the calculating equation, the flexural toughness of plain concrete decrease too. Meanwhile, the changing tendency of PCER value along with the K value manifests that when evaluating the flexural toughness of different quality concrete, the same K value should be used.

scholarly journals Behavior of high performance artificial lightweight aggregate concrete reinforced with hybrid fibers

2018 ◽  
Vol 162 ◽  
pp. 02001
Author(s):  
Wasan Khalil ◽  
Hisham Ahmed ◽  
Zainab Hussein
Keyword(s):  
Tensile Strength ◽  
Aspect Ratio ◽  
Steel Fiber ◽  
Fiber Type ◽  
Lightweight Aggregate ◽  
Plain Concrete ◽  
Splitting Tensile Strength ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber

In this investigation, sustainable High Performance Lightweight Aggregate Concrete (HPLWAC) containing artificial aggregate as coarse lightweight aggregate (LWA) and reinforced with mono fiber, double and triple hybrid fibers in different types and aspect ratios were produced. High performance artificial lightweight aggregate concrete mix with compressive strength of 47 MPa, oven dry density of 1828 kg/m3 at 28 days was prepared. The Fibers used included, macro hooked steel fiber with aspect ratio of 60 (type S1), macro crimped plastic fiber (P) with aspect ratio of 63, micro steel fiber with aspect ratio of 65 (type S), and micro polypropylene fiber (PP) with aspect ratio of 667. Four HPLWAC mixes were prepared including, one plain concrete mix (without fiber), one mono fiber reinforced concrete mixes (reinforced with plastic fiber with 0.75% volume fraction), one double hybrid fiber reinforced concrete mixes (0.5% plastic fiber + 0.25% steel fiber type S), and a mix with triple hybrid fiber (0.25% steel fiber type S1+ 0.25% polypropylene fiber + 0.25% steel fiber type S). Fresh (workability and fresh density) and hardened concrete properties (oven dry density, compressive strength, ultrasonic pulse velocity, splitting tensile strength, flexural strength, static modules of elasticity, thermal conductively, and water absorption) were studied. Generally, mono and hybrid (double and triple) fiber reinforced HPLWAC specimens give a significant increase in splitting tensile strength and flexural strength compared with plain HPLWAC specimens. The percentage increases in splitting tensile strength for specimens with mono plastic fiber are, 20.8%, 31.9%, 36.4% and 41%, while the percentage increases in flexure strength are 19.5%, 37%, 33.9% and 34.2% at 7, 28, 60, 90 days age respectively relative to the plain concrete. The maximum splitting tensile and flexure strengths were recorded for triple hybrid fiber reinforced HPLWAC specimens. The percentage increases in splitting tensile strength for triple hybrid fiber reinforced specimens are 19.5%, 37%, 33.9% and 34.2%, while the percentage increases in flexure strength are 50.5%, 62.4. %, 66.8% and 62.2% at 7, 28, 60 and 90 days age respectively relative to the plain concrete specimens.

scholarly journals Study of the Influence of Fibres Type and Dosage on Properties of Concrete for Airport Pavements

2019 ◽  
Vol 8 (1) ◽  
pp. 102-113
Author(s):  
Mihai Dicu ◽  
Andreea Matei ◽  
Constantin Dorinel Voiniţchi
Keyword(s):  
Flexural Strength ◽  
High Performance ◽  
Steel Fiber ◽  
Fiber Type ◽  
Polypropylene Fiber ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Portland Cement Concrete ◽  
Bearing Strength

Abstract The paper follows the potential practice of fiber reinforced concrete (FRC) as a solution for airport`s runway pavements, in order to increase the bearing strength, resulting in decreasing the height of the concrete layer that is currently used. Experimentally, the study focuses on the properties of fiber reinforced Portland cement concrete using 3 different percentages (0.5%, 1% and 1.5% of the concrete volume) and 4 different types of fiber (for 1% percentage – hooked steel fiber 50 mm length, hooked steel fiber 30 mm length, crimped steel fiber 30 mm length and polypropylene fiber 50 mm lenght), using as reference a plain concrete with 5 MPa flexural strength. More exactly, the study presents the change in compressive and flexural strength, shrinkage, thermal expansion factor, elastic modulus and Poisson`s ratio over fiber type and dosage. For the highest performance concrete (7 MPa flexural strength), it has been made a study using two methods for rigid airport pavements design (general method and optimized method), and one method for evaluation of bearing strength (ACN – PCN method), which is compared to a plain 5 MPa concrete. Furthermore, the decrease in the slab`s thickness proportionally to the growth of the flexural strength is emphasized by evaluating the slab`s height for a high performance 9 MPa concrete using both design methods.

scholarly journals Efficiency of Steel Fiber on Carrying Capacity of Short Square Columns

2018 ◽  
Vol 4 (7) ◽  
pp. 1584
Author(s):  
Haider Abdulridha Alkufi ◽  
Mohannad Husain Al-Sherrawi
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Applied Load ◽  
Ultimate Load ◽  
Steel Fiber ◽  
Fiber Type ◽  
Bending Moment ◽  
Plain Concrete ◽  
Steel Fibers ◽  
Moment Capacity

An experimental investigation is carried out to find the beneficial effect of adding steel fiber to reinforced concrete square columns. Hooked end steel fiber type is used in this investigation. The aspect ratio is 60 and the percentages of the steel fiber that added to the concrete are 0.5%, 1.0% and 1.5%. The experimental work consists of fabricated twenty columns to observe the effect of steel fibers on the axial and bending moment capacity. The specimens are classified into five groups according to the applied load on it. Each of these groups is consisted of four columns having different steel fiber ratios (0, 0.5, 1.0 and 1.5) %. The columns are tested under concentric, eccentric with variable eccentricities and two-point loading. All tested columns in a one group having the same dimensions, same interior reinforcement and were tested under one applying–load and they have a square cross-section with a dimension of (100 × 100) mm. Specimens with steel fiber results are compared with the control specimen of their own (columns mad of plain concrete). The results showed that increasing steel fiber ratio is caused an increasing in the first cracking load and an increase in the ultimate load for all tested columns.

Scanning Secondary Electron Microscopy of Myofibrils Using Transmission Techniques

1975 ◽  
Vol 33 ◽  
pp. 556-557
Author(s):  
M. K. Lamvik
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Carbon Films ◽  
Photographic Recording ◽  
Transmission Electron ◽  
Thin Carbon ◽  
The Common ◽  
Scanning Electron ◽  
Better Than ◽  
Cellular Organelles

When observing small objects such as cellular organelles by scanning electron microscopy, it is often valuable to use the techniques of transmission electron microscopy. The common practice of mounting and coating for SEM may not always be necessary. These possibilities are illustrated using vertebrate skeletal muscle myofibrils.Micrographs for this study were made using a Hitachi HFS-2 scanning electron microscope, with photographic recording usually done at 60 seconds per frame. The instrument was operated at 25 kV, with a specimen chamber vacuum usually better than 10-7 torr. Myofibrils were obtained from rabbit back muscle using the method of Zak et al. To show the component filaments of this contractile organelle, the myofibrils were partially disrupted by agitation in a relaxing medium. A brief centrifugation was done to clear the solution of most of the undisrupted myofibrils before a drop was placed on the grid. Standard 3 mm transmission electron microscope grids covered with thin carbon films were used in this study.

Evaluation of Gas-Liquid Chromatography in Assays for Blood Volatiles

1965 ◽  
Vol 11 (11) ◽  
pp. 1023-1035 ◽  
Author(s):  
Alan Mather ◽  
Angel Assimos
Keyword(s):  
Liquid Chromatography ◽  
Alcohol Concentration ◽  
Quantitative Assay ◽  
Gas Liquid Chromatography ◽  
Internal Reference ◽  
Detection And Identification ◽  
Large Populations ◽  
The Common ◽  
Low Levels ◽  
Better Than

Abstract A simple screening by gas-liquid chromatography (GLC) can provide definitive answers in the detection and identification of a number of volatile substances, including acetone and the common alcohols. After identification, quantitative assay by an internal-reference technic yields highly specific values for ethyl alcohol concentration with a precision at least equal to (and for low levels, better than) that of conventional assays. The unique advantage of GLC is in its simultaneous quantitative assay of mixtures, some of which cannot be satisfactorily assayed or even recognized in any other way. The combination of speed and negligible sample volumes render the technic valuable for sequential studies on capillary blood samples and, potentially, for mass screening of large populations.

Preparation and Long-Term Stability Study of Steel Fiber/Graphite Conductive Concrete

2016 ◽  
Vol 680 ◽  
pp. 361-364 ◽  
Author(s):  
Jun Du ◽  
Cheng Tang ◽  
Bo Jia ◽  
De Zhang ◽  
Qiang Miao
Keyword(s):  
Corrosion Resistance ◽  
Steel Fiber ◽  
Stability Study ◽  
Soil Resistivity ◽  
Grounding Resistance ◽  
Term Stability ◽  
Long Term Stability ◽  
Conductive Fillers ◽  
The Common

The steel fiber/graphite conductive concrete is applied in power system grounding. In high soil resistivity regions, the common methods for reducing the grounding resistance are not practical. It is difficult for grounding resistance of substations to meet the requirements of working earthing and safety earthing. In order to solve this problem, a steel fiber/graphite conductive concrete is developed in this paper. Steel fiber and graphite are added as conductive fillers. The long-term stability of the steel fiber/graphite conductive concrete is studied. The experiment results show that steel fiber/graphite conductive concrete not only maintains excellent conductivity, but also has good mechanical strength and corrosion resistance in 300 days.

scholarly journals A novel experimental method to characterise the shear strength of concrete based on pre-stressed samples. A comparison with existing techniques

2018 ◽  
Vol 183 ◽  
pp. 02049
Author(s):  
Pascal Forquin ◽  
Reem Abdul-Rahman ◽  
Dominique Saletti
Keyword(s):  
Experimental Method ◽  
Shear Fracture ◽  
Plain Concrete ◽  
Concrete Specimen ◽  
Compression Tests ◽  
Second Stage ◽  
Wide Range ◽  
Metallic Ring ◽  
Do So ◽  
Metallic Cell

Mode II shear fracture process can be observed in plain-concrete structures exposed to intensive loadings such as shock, blasting or projectile-impact. It is the reason why the quasi-static and dynamic shear fracturing properties of concrete need to be investigated. In previous works performed by Forquin and coauthors a passive confining cell was applied to PTS (Punch-Through-Shear) specimens in a similar way than in quasi-oedometric compression tests where metallic ring are used as passive confinement. However the change of confining level during the sample loading constitutes a main drawback of this technique. In the present work a novel testing method is proposed based on a pre-stressing of the sample. To do so, the concrete specimen is inserted into pre-stressed metallic cell. During the unloading stage confining stresses are transferred to the ligament of the sample. In a second stage, a differential displacement applied to the central part of the sample toward the side parts produces a shearing of the ligament. The experiments performed in static and dynamic conditions (SHPB testing) allow the shear response of concrete to be determined over a wide range of strain-rates. In the present communication, the testing technique and obtained results are compared to the obtained data with the previous experimental method.

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