The Effect of Specimen Shape on the Mechanical Properties of Sisal Fiber-Reinforced Concrete

Abass Abayomi Okeola1, *, Silvester Ochieng Abuodha2, John Mwero2
1 Civil Engineering Department, Pan African University Institute for Basic Science, Technology and Innovation Hosted at Jomo Kenyatta University , Nairobi, Kenya
2 Civil Engineering Department, University of Nairobi, Nairobi, Kenya.



Fiber reinforced concrete is becoming popular in improving the quasi-brittle failure of concrete. Natural fibers such as sisal hold great promise in this regard. It has amazing tensile strength and is renewable. This paper presents the result of an investigation carried out on the effect of sisal fiber on the compressive strength, Split tensile strength, failure mode and Poisson ratio of sisal fiber-reinforced concrete (SFRC).


A mix proportion of 1:1.92:3.68 and w/c ratio of 0.47 for a target compressive strength of 35 MPa was used. Sisal fiber was added at percentages of 0.5%, 1.0%, 1.5%, and 2.0% by weight of cement. The effect of specimen shape on the compressive strength of sisal fiber-reinforced concrete (SFRC) was reported. The compressive strength of cube (150mm X 150mm) and cylinder (150mm diameter and 300mm height) specimen was determined at 7 and 28 days, while Split tensile strength and Poisson ratio were obtained using cylindrical specimen (150mm diameter and 300mm height).

Results and Conclusion:

The result shows that the addition of sisal fiber slightly reduces the compressive strength of concrete, increases its split tensile strength up to 47.167% of the control specimen, arrests crack propagation and reduces its Poisson ratio. The correlation between the compressive strength of cylindrical and cube specimen was established with a ratio ranging between 0.82 - 0.73. The difference in the compressive strength was found to increase with rise in the percentages of sisal fiber. Based on the strength ratio and mechanical properties, 1.0% sisal fiber content was recommended as the optimum for reinforcing concrete.

Keywords: Sisal fiber, Shape effect, Compressive strength, Split tensile strength, Crack formation, Poisson ratio.

Abstract Information

Identifiers and Pagination:

Year: 2018
Volume: 12
Publisher Item Identifier: EA-TOCIEJ-2018-48

Article History:

Received Date: 04/08/2018
Revision Received Date: 02/10/2018
Acceptance Date: 17/10/2018
Electronic publication date: 29/10/2018
Collection year: 2018

© 2018 Okeola et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Correspondence: Address correspondence to this author at the Civil Engineering Department, Pan African University Institute for Basic Science, Technology and Innovation Hosted at Jomo Kenyatta University, Nairobi, Kenya; Tel:+254797648182; E-mails:,