Self-Consolidating Fiber Reinforced Concrete (SCFRC)

Fiber Reinforced Concrete (FRC) requires a high degree of vibration to get good compactness. This increases the labor costs and noise pollution at the work site. Moreover, if the reinforcement is dense or the form is intricate in shape, it becomes even more difficult to place and vibrate the concrete. Unfortunately, when one tries to enhance the workability of FRC by adding more superplasticizers or intensifying the degree of vibration, segregation invariably occurs. Hence, the development of a self-consolidating fiber reinforced concrete (SCFRC) should make for easier placement of concrete, save labor and avoid noise pollution. SCC offers several economic and technical benefits; the use of steel fibers extends its possibilities [148].

When steel fibers are added to the concrete mix, the tensile and shear resistance of the composite material is enhanced. However, fibers are also known to impede the workability of plain concrete. Moreover, the end zones are densely reinforced making it necessary to use a highly workable concrete with steel fibers that would not only reduce or completely eliminate the conventional reinforcement but also make it easier to place concrete. The use of SCFRC would guarantee the following advantages:

• Fibers in SCFRC are expected to partially or fully replace the dense reinforcement and also control concrete cracking.

• SCFRC would be easier to place and finish than the conventional FRC.

• The shear, flexural and tensile strengths along with ductility and toughness are expected to be improved with the use of SCFRC mixtures.

• SCFRC might prove to be more economical in the long run, owing to the fact that labor and time is saved with the use of SCFRC.

Some research experiments as well as field applications have been successfully carried out on SCFRC. The mix design of SCFRC could be based on the mix design of an existing SCC mix [154]. The workability of SCFRC is affected by fibers as they posses high surface area. The degree to which workability decreases depends on the type and content of fibers, the matrix composition and the properties of the constituents of the matrix on their own. The higher the fiber content in SCFRC, more difficult it becomes to uniformly distribute the fibers in the matrix [148]. Concrete with satisfactory workability could be made self-consolidating even with a large fiber content of up to 1.3% by volume [155].

Updated: 15 сентября, 2015 — 5:43 пп