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.

Determination of fiber volume fraction in a cured laminate

2021 ◽  
pp. 002199832110112
Author(s):  
Qing Yang Steve Wu ◽  
Nan Zhang ◽  
Weng Heng Liew ◽  
Vincent Lim ◽  
Xiping Ni ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Volume Fraction ◽  
Evaluation Method ◽  
Volume Fraction ◽  
Matrix Material ◽  
Volume Ratio ◽  
Gravimetric Analysis ◽  
Fiber Volume ◽  
Laser Ultrasonic ◽  
The Matrix

Propagation of ultrasonic wave in Carbon Fiber Reinforced Polymer (CFRP) is greatly influenced by the material’s matrix, resins and fiber volume ratio. Laser ultrasonic broadband spectral technique has been demonstrated for porosity and fiber volume ratio extraction on unidirection aligned CFRP laminates. Porosity in the matrix materials can be calculated by longitudinal wave attenuation and accurate fiber volume ratio can be derived by combined velocity through the high strength carbon fiber and the matrix material with further consideration of porosity effects. The results have been benchmarked by pulse-echo ultrasonic tests, gas pycnometer and thermal gravimetric analysis (TGA). The potentials and advantages of the laser ultrasonic technique as a non-destructive evaluation method for CFRP carbon fiber volume fraction evaluation were demonstrated.

scholarly journals Fracture Properties and Softening Curves of Steel Fiber-Reinforced Slag-Based Geopolymer Mortar and Concrete

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1445 ◽  
Author(s):  
Yao Ding ◽  
Yu-Lei Bai
Keyword(s):  
Fracture Toughness ◽  
Fracture Energy ◽  
Inverse Analysis ◽  
Steel Fiber ◽  
Mouth Opening ◽  
Crack Mouth Opening Displacement ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Opening Displacement ◽  
Fracture Properties

Adding short steel fibers into slag-based geopolymer mortar and concrete is an effective method to enhance their mechanical properties. The fracture properties of steel fiber-reinforced slag-based geopolymer concrete/mortar (SGC/SGM) and unreinforced control samples were compared through three-point bending (TPB) tests. The influences of steel fiber volume contents (1.0%, 1.5% and 2.0%) on the fracture properties of SGC and SGM were studied. Load-midspan deflection (P-δ) curves and load-crack mouth opening displacement (P-CMOD) curves of the tested beams were recorded. The compressive and splitting tensile strengths were also tested. The fracture energy, flexural strength parameters, and fracture toughness of steel fiber-reinforced SGC and SGM were calculated and analyzed. The softening curves of steel fiber-reinforced SGC and SGM were determined using inverse analysis. The experimental results show that the splitting tensile strength, fracture energy, and fracture toughness are significantly enhanced with fiber incorporation. A strong correlation between the equivalent and residual flexural strengths is also observed. In addition, the trilinear strain-softening curves obtained by inverse analysis predict well of the load-displacement curves recorded from TPB tests.

Cropped Steel Fiber Reinforced Chemically Bonded Ceramic (CBC) Composites

1987 ◽  
Vol 114 ◽  
Author(s):  
Sean Wise ◽  
Kevan Jones ◽  
Claudio Herzfeld ◽  
David D. Double
Keyword(s):  
Silica Fume ◽  
Steel Fiber ◽  
High Strength ◽  
Cement Matrix ◽  
Metal Fiber ◽  
Morphological Form ◽  
The Matrix ◽  
Compressive And Flexural Strengths ◽  
Equivalent Properties ◽  
Very High

ABSTRACTVery high strength castable chemically bonded ceramic (CBC) materials have been prepared which consist of finely chopped steel fibers and steel aggregate in a silica modified portland cement matrix. This paper examines the effect of metal fiber addition on compressive and flexural strengths. The overall chemistry of the matrix is held constant but the morphological form of silica used and the cure conditions are altered to examine their effect. Compressive strengths in excess of 500 MPa and flexural strengths in excess of 80 MPa can be obtained.It is found that flexural strength increases proportionally with fiber content over the range of 0 to 10% by volume. Compressive strengths are not affected. Use of silica fume in the mixes produces higher strengths at low temperatures than mixes which contain only crystalline silica. High temperature curing/drying (400°C), which produces the highest strengths, produces equivalent properties for formulations with and without silica fume. Higher water/cement ratios are found to reduce compressive strengths but have relatively little effect on the flexural properties.

Experimental Study on Flexural and Fatigue Property of Steel Fiber Reinforced Prestressed Concrete Slab

2012 ◽  
Vol 166-169 ◽  
pp. 1083-1086
Author(s):  
Shi Yue Wang ◽  
Jie Hou ◽  
Bi Huang
Keyword(s):  
Flexural Strength ◽  
Plastic Strain ◽  
Strain Amplitude ◽  
Prestressed Concrete ◽  
Strain Energy ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Volume Ratio ◽  
Fiber Volume ◽  
Plastic Strain Energy

The flexural strength of steel fiber reinforced prestressed concrete slab (SFRPCS) with different steel fiber volume ratio (0%, 1%, 2%) is obtained according to four-point bend test, which reveals that the addition of steel fiber can retard the crack growth and enhance the flexural strength of SFRPCS. With the results of fatigue experiment, the damage forms of SFRPCS is analyzed, strain amplitude-cycle ratio curves are obtained and the plastic strain energy of SFRPCS with different steel fiber volume ratio during fatigue process is calculated. It is shown that after 80% fatigue life, the more of the steel fiber volume ratio, the less of the strain amplitude increment, which proves the addition of steel fiber can prevent the concrete matrix from cracking and improve the fatigue performance of SFRPCS, and the plastic strain energy curve of SFRPCS shows obviously three- stage development.

Mechanical Property of Hybrid Steel Fiber Reinforced Cement-Based Composites

2013 ◽  
Vol 539 ◽  
pp. 99-102
Author(s):  
Hai Tao Tan ◽  
Wu Yao ◽  
Xiao Ming Song ◽  
Shuai Dong
Keyword(s):  
Mechanical Property ◽  
Fracture Energy ◽  
Fiber Volume Fraction ◽  
Ultimate Load ◽  
Bending Strength ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Reinforced Cement

The ultimate load, fracture energy and equivalent bending strength of hybrid steel fiber reinforced mortar were investigated with a constant fiber volume fraction in this paper. The results showed that ultimate load of hybrid steel-fiber reinforced mortar was higher than that of mono-fiber reinforced mortar; fracture energy and equivalent bending strength increased with the volume fraction of steel fiber with end hooks.

scholarly journals Mechanical Properties of Hybrid Fiber Reinforced Rubber Concrete

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6028
Author(s):  
Qiang Su ◽  
Jin-Ming Xu ◽  
Yong-Dong Wang
Keyword(s):  
Mechanical Properties ◽  
Resistance Mechanism ◽  
Basalt Fiber ◽  
Volume Ratio ◽  
Hybrid Fiber ◽  
Fiber Volume ◽  
Hybrid Effect ◽  
Orthogonal Experiments ◽  
Pva Fiber ◽  
Rubber Concrete

Orthogonal experiments were designed for hybrid fiber rubber concrete (HFRC). The mechanical properties of HFRC were tested and compared with ordinary concrete. The effects of basalt fiber volume ratio (VBF), PVA fiber volume ratio (VPF) and rubber volume ratio (VR) on the compressive strength, splitting tensile strength and flexural strength of HFRC were analyzed. The results show that the strength of HFRC is the best when the volume ratio of basalt fiber is 0.3%, the volume ratio of PVA fiber is 0.2% and the volume ratio of rubber is 5%. Basalt fiber has the greatest influence on the strength of HFRC. The strength of HFRC mixed with hybrid fiber is greatly improved, which reflects the good fiber “positive hybrid effect”. With the increase of rubber volume ratio, the strength of HFRC decreases gradually. With the help of SEM and EDS, the toughening and cracking resistance mechanism of the fiber to HFRC was analyzed. Finally, the strength of HFRC was predicted by model.

Spall Strength of Steel Fiber Reinforced Concretes

2015 ◽  
Vol 1120-1121 ◽  
pp. 1468-1474
Author(s):  
Lei Zhang ◽  
Biao Wu ◽  
Ying Zhou
Keyword(s):  
Steel Fiber ◽  
Spall Strength ◽  
Volume Ratio ◽  
Spall Fracture ◽  
Fiber Reinforced ◽  
Hopkinson Pressure Bar ◽  
Fiber Volume ◽  
Load Rate ◽  
Real Importance ◽  
Pressure Bar

The spall fracture of steel fiber reinforced concretes (SFRC) is investigated with the strain wave profiles in buffer bar behind the specimen bar in a large size Hopkinson pressure bar equipment. The experimental results indicate that the spall strength of SFRC is related to the steel fiber volume ratio, the compressive strength of concretes and the load rate (impact velocity). The spall strength of SFRC empirical formula shows the relationship between these factors. The conclusion that the steel fiber has the effect to improve the ability to prevent spall fracture is of real importance in the correlative numerical simulation and protective engineering design.

scholarly journals Mechanical Properties and Durability of Polypropylene and Steel Fiber-Reinforced Recycled Aggregates Concrete (FRRAC): A Review

2020 ◽  
Vol 12 (22) ◽  
pp. 9509
Author(s):  
Peng Zhang ◽  
Yonghui Yang ◽  
Juan Wang ◽  
Shaowei Hu ◽  
Meiju Jiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Steel Fiber ◽  
Mechanical Performance ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Chloride Permeability ◽  
High Durability ◽  
The Matrix ◽  
Research Findings ◽  
Fiber Materials

With the development of concrete engineering, a large amount of construction, demolition, excavation waste (CDEW) has been produced. The treated CDEW can be used as recycled aggregate to replace natural aggregate, which can not only reduce environmental pollution and construction-related resource waste caused by CDEW, but also save natural resources. However, the mechanical properties and durability of Recycled Aggregates Concrete (RAC) are generally worse than that of ordinary concrete. Various fiber or mineral materials are usually used in RAC to improve the mechanical properties and durability of the matrix. In RAC, polypropylene (PP) fiber and steel fiber (SF) are two kinds most commonly used fiber materials, which can enhance the strength and toughness of RAC and compensate the defects of RAC to some extent. In this paper, the literature on PP fiber- and SF-reinforced RAC (FRRAC) is reviewed, with a focus on the consistence, mechanical performance (compressive strength, tensile strength, stress–strain relationship, elastic modulus, and shear strength), durability (water absorption, chloride permeability, carbonation, freeze–thaw cycling, and shrinkage), and microstructure. The research findings regarding FRRAC were analyzed and compared. The results showed that adding mineral additives and fiber in RAC had a good synergistic effect, which made FRRAC have good mechanical properties, high durability and high temperature resistance, and several application prospects. The information and summary presented in this paper exhibit new knowledge and information on the application of FRRAC.

Effect of Interphases on Micro and Macromechanical Behavior of Hexagonal-Array Fiber Composites

1990 ◽  
Vol 57 (4) ◽  
pp. 956-963 ◽  
Author(s):  
J. D. Achenbach ◽  
H. Zhu
Keyword(s):  
Fiber Composite ◽  
Volume Ratio ◽  
Fiber Composites ◽  
Effective Moduli ◽  
Hexagonal Array ◽  
Fiber Volume ◽  
Unidirectional Fiber Composite ◽  
Circumferential Tensile Stress ◽  
The Matrix ◽  
Stress And Deformation

The effect of interphase stiffness on microstresses and macromechanical behavior has been investigated for transverse loading of an hexagonal-array unidirectional fiber composite. The interphase is modeled by a layer which resists radial extension and circumferential shear deformation. Taking advantage of the periodicity of the medium, the states of stress, and deformation in a basic cell have been analyzed numerically by the use of the boundary element method. The circumferential tensile stress along the matrix side of the interphase and the radial stress in the interphase have been analyzed for various values of the interphase parameters and the fiber volume ratio. The micromechanical results have also been used to determine the effect of interphase stiffness on the effective moduli. The calculated values have been compared with analytical results that were adjusted for interphase stiffness.

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