Title:
Performance of Hemp Micro- and Macrofiber in Cement Mortar (Open Source)
Author(s):
Brian Giltner, Seamus Freyne, and Anthony J. Lamanna
Publication:
Materials Journal
Volume:
121
Issue:
4
Appears on pages(s):
3-12
Keywords:
bonding; fibers; hemp; tensile capacity; twine; water-cement ratio
DOI:
10.14359/51740822
Date:
8/1/2024
Abstract:
The focus of this study is to determine the optimum length of micro
(average diameter less than 0.3 mm) and macro (average diameter
greater than or equal to 0.3 mm) hemp fibers subjected to tensile
loading in a cement paste mixture. Optimizing the length of the
fibers to carry tensile loading for concrete members is important
to minimize waste of hemp material and to provide the best performance. This study evaluated three water-cement ratios (w/c):
0.66, 0.49, and 0.42 (fc′ = 17.2, 24.1, and 27.6 MPa [2500, 3500,
and 4000 psi], respectively). Because of the high cost of cement,
replacement of cement with fly ash was also part of the program to
determine if the addition of fly ash would have a negative impact
on the performance of the hemp fibers. The results show that hemp
micro- and macrofibers bonded to the cement matrix and carry
higher tensile loads at higher w/c. Statistical analysis (regression
modeling) shows that the optimum length for hemp macrofibers is
30 and 20 mm (1.18 and 0.79 in.) for microfibers.