Fracture Model for Fiber Reinforced Concrete

The flexural response of ultrahigh performance fiber-reinforced concrete (UHPFRC) was simulated based on the lattice fracture model. Fiber was modelled as separated beam that was connected to the matrix with interface beams. The simulated results were compared with the experimental results. Deviations occurred at the late stage of the strain-softening period. But both the strain-hardening behavior and multicracking phenomenon were observed in the simulation. The effects of fiber orientation and fiber content were studied with the lattice fracture model. The flexural strength and toughness of UHPFRC improved as the fibers were aligned distributed or the fiber content increased. The proposed model has the potential to help with the materials design of UHPFRC, and the limitations of the model were also discussed in the paper.

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Mode I Non-Linear Fracture Model: Cases on Concrete and Fiber Reinforced Concrete

Jurnal Teknik Sipil ◽

10.28932/jts.v4i2.1305 ◽

2019 ◽

Vol 4 (2) ◽

pp. 150-165

Author(s):

M.I Retno Susilorini

Keyword(s):

Reinforced Concrete ◽

Fiber Reinforced Concrete ◽

Fracture Model ◽

Mode I ◽

Fiber Reinforced ◽

Linear Fracture ◽

Non Linear

Model fraktur ragam I non-linier telah banyak digunakan untuk memperoleh faktor intensitastegangan KSIc dan perpindahan bukaan ujung retak CTODc sebagai kriteria fraktur untuk beton danbeton serat. Beberapa model fraktur ragam I non-linier terdahulu antara lain Model Retak Fiktif olehHillerborg, (1976), Model Pita Retak oleh Bazant (1983, 1986), Model Dua-Parameter oleh Jenq danShah (1986), Model Penjalaran Retak Mode I oleh Zhang dan Li (2005), dan Model Kerusakan Non-Lokal oleh Ferrara dan Prisco (2005). Tulisan ini mengimplementasikan model fraktur ragam I nonlinierpada 2 kasus. Kasus pertama diimplementasikan pad beton sedangkan kasus keduadiimplementasikan pada beton serat. Kedua kasus tersebut akan memperoleh nilai faktor intensitastegangan KSIc dan perpindahan bukaan ujung retak CTODc. Kasus 1 adalah kasus benda uji balokbeton bertakik model fraktur ragam I non-linier dan kasus 2 adalah beton serat tak hingga modelfraktur ragam I non-linier. Kasus 1 menghasilkan nilai faktor intensitas tegangan KSIc sebesar 15.078MPa mm-1/2 dan perpindahan bukaan ujung retak CTODc sebesar 0.023 mm. Kasus 1 menghasilkannilai faktor intensitas tegangan KSIc sebesar 3.917.10-4 MPa mm-1/2 dan perpindahan bukaan ujung retak CTODc sebesar –1.994.10-4 mm. Secara umum, keberadaan serat sangat mempengaruhi solusianalitis. Tulisan ini memperoleh kesimpulan sebagai berikut: (1) Model fraktur ragam I non-linierdapat digunakan untuk memperoleh faktor intensitas tegangan KSIc dan perpindahan bukaan ujungretak CTODc sebagai kriteria fraktur untuk beton dan beton serat, (2) Perilaku fraktur beton seratadalah spesifik dibandingkan beton karena adanya fenomena penjembatanan serat, (3) Dalamperhitungan hasil faktor intensitas tegangan KSIc dan perpindahan bukaan ujung retak CTODc akanberlebihan bila traksi serat diabaikan dan kurang bila Zona Proses Fraktur diabaikan, (4) Akan sangatbaik bila mengkombinasikan Kasus 1 dan Kasus 2 bersama-sama untuk memperoleh nilai faktorintensitas tegangan KSIc dan perpindahan bukaan ujung retak CTODc dengan memperhatikankeberadaan serat dalam komposit matriks berserat.

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Fracture Model to Predict Stress Intensity in Fiber Reinforced Concrete

ACI Materials Journal ◽

10.14359/2162 ◽

1991 ◽

Vol 88 (5) ◽

Keyword(s):

Reinforced Concrete ◽

Stress Intensity ◽

Fiber Reinforced Concrete ◽

Fracture Model ◽

Fiber Reinforced

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Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.14.2.2020.15.0527 ◽

2020 ◽

Vol 14 (2) ◽

pp. 6734-6742

Author(s):

A. Syamsir ◽

S. M. Mubin ◽

N. M. Nor ◽

V. Anggraini ◽

S. Nagappan ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Compressive Strength ◽

Reinforced Concrete ◽

Impact Resistance ◽

Fiber Reinforced Concrete ◽

Steel Fibers ◽

Fiber Reinforced ◽

Indirect Tensile ◽

The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study. The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.

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