FRP-Needles as Discrete Reinforcement in Concrete
Publication: Journal of Materials in Civil Engineering
Volume 29, Issue 10
Abstract
This paper presents a new type of discrete reinforcing element for concrete produced from either waste or new pultruded fiber-reinforced polymer (FRP) composite materials. These elements, referred to as FRP-Needles, are rigid, long, and low in aspect ratio, and have distinct physical and mechanical differences from macrofibers used in concrete. The FRP-Needles used in this study were produced by cutting FRP reinforcing bar (rebar) production scrap with nominal diameter of 6 mm into rod-shape elements with length of 100 mm (aspect ratio of 17). FRP-Needles were incorporated in concrete to replace 5 and 10% of coarse natural aggregate (NA) by volume. The needles did not reduce the workability or stability of concrete. The dispersion and orientation of FRP-Needles in concrete were relatively uniform. The 5 and 10% replacement of NA with FRP-Needles increased the splitting tensile strength of concrete by 22 and 33%, respectively, while reducing the compressive strength by only 5 and 9%. The incorporation of FRP-Needles in concrete resulted in significant increases in postfailure toughness of concrete in both compression and tension. In a parallel study, FRP recycled aggregate (FRP-RA) was produced by cutting scrap rebars into cylindrical pieces with aspect ratio of 1. FRP-RA was incorporated in concrete with the aforementioned dosages to observe the effect of geometrical characteristics of FRP elements on the studied mechanical properties of concrete. The improvements achieved by using FRP-Needles were not observed when FRP-RA was incorporated in concrete.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The support of the New York State Energy Research and Development Authority (NYSERDA) under the grant C2CUNY1 by the PowerBridgeNY Program is acknowledged. The authors wish to thank Mr. Doug Gremel from Hughes Brothers, Inc., for providing the FRP reinforcing bar production waste and technical information.
References
ACI (American Concrete Institute). (2007). “Report on fiber-reinforced polymer (FRP) reinforcement for concrete structures.” ACI 440R, Farmington Hills, MI.
ACI (American Concrete Institute). (2009). “Report on fiber reinforced concrete, 544.1 R-96 (reapproved 2009).” ACI 544.1, Farmington Hills, MI.
ACI (American Concrete Institute). (2015). “Guide for the design and construction of structural concrete reinforced with fiber-reinforced polymer bars.” ACI 440.1R, Farmington Hills, MI.
Altoubat, S., Yazdanbakhsh, A., and Rieder, K.-A. (2009). “Shear behavior of macro-synthetic fiber-reinforced concrete beams without stirrups.” ACI Mater. J., 106(4), 381–389.
ASTM. (2011). “Standard test method for splitting tensile strength of cylindrical concrete specimens.” ASTM C496, West Conshohocken, PA.
ASTM. (2012). “Standard test method for flexural performance of fiber-reinforced concrete (using beam with third-point loading).” ASTM C1609, West Conshohocken, PA.
ASTM. (2013). “Standard specification for concrete aggregates.” ASTM C33, West Conshohocken, PA.
ASTM. (2014). “Standard test method for static modulus of elasticity and Poisson’s ratio of concrete in compression.” ASTM C469, West Conshohocken, PA.
ASTM. (2015a). “Standard test method for compressive strength of cylindrical concrete specimens.” ASTM C1231, West Conshohocken, PA.
ASTM. (2015b). “Standard test method for compressive strength of cylindrical concrete specimens.” ASTM C39, West Conshohocken, PA.
ASTM. (2015c). “Standard test method for obtaining average residual-strength of fiber-reinforced concrete.” ASTM C1399, West Conshohocken, PA.
ASTM. (2015d). “Standard test method for slump of hydraulic-cement concrete.” ASTM C143, West Conshohocken, PA.
Bank, L. C. (2006). Composites for construction, Wiley, Hoboken, NJ.
Benmokrane, B., Tighiouart, B., and Chaallal, O. (1996). “Bond strength and load distribution of composite GFRP reinforcing bars in concrete.” ACI Mater. J., 93(3), 246–253.
Bentur, A., and Mindess, S. (2007). Fiber reinforced cementitious composites, Taylor & Francis, New York.
Choi, Y., and Yuan, R. L. (2005). “Experimental relationship between splitting tensile strength and compressive strength of GFRC and PFRC.” Cem. Concr. Res., 35(8), 1587–1591.
Katz, A. (1999). “Bond mechanism of FRP rebars to concrete.” Mater. Struct., 32(10), 761–768.
Khayat, K. H. (1999). “Workability, testing, and performance of self-consolidating concrete.” ACI Mater. J., 96(3), 346–353.
Murrell, S. (1993). “Concrete airport pavements make a comeback.” New York Construction News, McGraw Hill, New York.
Nanni, A. (1988). “Splitting-tension test for fiber reinforced concrete.” ACI Mater. J., 85(4), 229–233.
Nanni, A., Luca, A. D., and Jawaherizadeh, H. (2014). Reinforced concrete with FRP bars, mechanics and design, CRC Press, Boca Raton, FL.
Okelo, R., and Yuan, R. L. (2005). “Bond strength of fiber reinforced polymer rebars in normal strength concrete.” J. Compos. Constr., 203–213.
Patnaik, A., Miller, L., Adhikari, S., and Standal, P. (2013). “Basalt FRP minibar reinforced concrete.” Proc., Fiber Concrete, Czech Technical Univ. in Prague, Faculty of Civil Engineering, Prague, Czech Republic, 51–52.
Patnaik, A., Miller, L., and Standal, P. C. (2014). “Fiber reinforced concrete made from basalt FRP minibar.” Concrete Innovation Conf.—CIC 2014, Concrete Innovation Center, Oslo, Norway.
Reynolds, N., and Pharaoh, M. (2010). “An introduction to composites recycling.” Management, recycling and reuse of waste composites, V. Goodship, ed., Woodhead Publishing, Cambridge, U.K., 3–19.
Roesler, J. R., Altoubat, S. A., Lange, D. A., Rieder, K.-A., and Ulreich, G. R. (2006). “Effect of synthetic fibers on structural behavior of concrete slabs-on-ground.” ACI Mater. J., 103(1), 3–10.
Wafa, F., and Ashour, S. (1992). “Mechanical properties of high-strength fiber reinforced concrete.” ACI Mater. J., 89(5), 449–455.
Yazdanbakhsh, A. C., Bank, L., and Chen, C. (2016). “Use of recycled FRP reinforcing bar in concrete as coarse aggregate and its impact on the mechanical properties of concrete.” Constr. Build. Mater., 121, 278–284.
Information & Authors
Information
Published In
Copyright
©2017 American Society of Civil Engineers.
History
Received: Nov 10, 2016
Accepted: Apr 11, 2017
Published online: Jul 8, 2017
Published in print: Oct 1, 2017
Discussion open until: Dec 8, 2017
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.