Mechanical properties of kenaf fiber reinforced concrete: Fid-Bau Portal

Mechanical properties of kenaf fiber reinforced concrete

Elsaid, A. / Dawood, M. / Seracino, R. / Bobko, C.

Research highlights ► KFRC specimens exhibited a ductile behavior with greater energy absorption. ► Compressive elastic modulus of KFRC is considerably lower than plain concrete. ► ACI 318M-08 provisions related to the tensile strength are appropriate for KFRC. ► Toughness of the KFRC specimens was approximately three times that of plain concrete.

Abstract This paper presents the findings of an experimental research program that was conducted to study the mechanical properties of a natural fiber reinforced concrete (FRC) which is made using the bast fibers of the kenaf plant. The kenaf plant is quickly developing as a replacement crop for the dwindling tobacco industry in the south-eastern United States. Appropriate mixture proportions and mixing procedures are recommended to produce kenaf FRC (KFRC) with fiber volume contents of 1.2% and 2.4%. The compressive strength, compressive modulus, splitting tensile strength and modulus of rupture of KFRC specimens are presented and compared to the properties of plain concrete control specimens. The experimental results indicate that the mechanical properties of KFRC are comparable to those of plain concrete control specimens, particularly when accounting for the effect of the increased w/c ratio required to produce workable KFRC. Further, the results indicate that KFRC generally exhibits more distributed cracking and higher toughness than plain concrete. Scanning electron micrographs (SEM’s) indicate that a good bond between the kenaf fibers and the surrounding matrix is achieved. The SEM’s also provide interesting information regarding the mechanisms which contribute to the failure and post-peak behavior of the KFRC which may be beneficial to future modeling efforts. The research findings indicate that KFRC is a promising ‘green’ construction material which could potentially be used in a number of different structural applications.