Microfiber and Macrofiber Hybrid Fiber-Reinforced Concrete

To realize the potential of micro- and macrofiber blends in a concrete matrix, a concrete containing polyvinyl alcohol (PVA) or steel microfibers and steel macrofibers was designed using a mixture proportioning method that provides good workability in concretes containing microfibers. This procedure is based on an optimum paste volume fraction determined from the relationship between flow and paste content. The mechanical performance, water permeability of the cracked material, and shrinkage crack resistance of cast concrete were evaluated. In the hybrid concrete, the microfibers delayed the development of macrocracks and so the composite demonstrated greater strength and crack resistance than a similar matrix reinforced with macrofibers only. This influence was less pronounced than was observed with a mortar matrix in a previous study. This is explained by differences in the failure mechanism of the fibers: A stronger fiber-matrix bond resulting from a lower water-to-binder ratio caused the microfibers t...

[1]  Surendra P. Shah,et al.  Fiber-matrix interaction in microfiber-reinforced mortar , 1995 .

[2]  Surendra P. Shah,et al.  Fracture of concrete and rock : recent developments , 1989 .

[3]  Surendra P. Shah,et al.  Shrinkage cracking of fiber reinforced concrete , 1990 .

[4]  Davide Zampini,et al.  Permeability of Cracked Hybrid Fiber-Reinforced Mortar under Load , 2002 .

[5]  Surendra P. Shah,et al.  Effect of Length on Compressive Strain Softening of Concrete , 1997 .

[6]  Surendra P. Shah,et al.  Determination of fracture parameters (KIcs and CTODc) of plain concrete using three-point bend tests , 1990 .

[7]  A Hillerborg.  STABILITY PROBLEMS IN FRACTURE MECHANICS TESTING. FRACTURE OF CONCRETE AND ROCK: RECENT DEVELOPMENTS. PAPERS PRESENTED AT THE INTERNATIONAL CONFERENCE, UNIVERSITY OF WALES, COLLEGE OF CARDIFF, SCHOOL OF ENGINEERING, SEPTEMBER 20-22, 1989 , 1989 .

[8]  A. Hillerborg.  Stability Problems in Fracture Mechanics Testing , 1989 .

[9]  N. Banthia,et al.  Micro-Reinforced Cementitious Materials , 1990 .

[10]  Sidney Mindess,et al.  Fibre Reinforced Cementitious Composites , 1990 .

[11]  B. Mobasher,et al.  Mechanical Properties of Hybrid Cement-BasedComposites , 1996 .

[12]  S. Mindess,et al.  Fiber-reinforced cementitious materials , 1991 .

[13]  Seisuke Okubo,et al.  Complete stress-strain curves for various rock types in uniaxial tension , 1996 .

[14]  Chunxiang Qian,et al.  Development of hybrid polypropylene-steel fibre-reinforced concrete , 2000 .

[15]  Antoine E. Naaman,et al.  Bond-Slip Mechanisms of Steel Fibers in Concrete , 1991 .