| dc.description.abstract | The mechanical stability of mine backfill materials is crucial for the safety of mining
personnel and production efficiency. When placed into mined-out voids, known as stopes,
mine backfill materials are required to provide reliable secondary ground support, which
is subjected to finite deformation loading, especially in deep mines. However, due to the
quasi-brittle characteristics of cemented paste backfill (CPB), these materials possess
very limited post-peak resistance. Enhancing the post-peak engineering performance of
CPB is achievable through natural fiber reinforcement techniques. In this study, hemp
fibers were selected for their abundant availability in Canada. To investigate their
effectiveness in terms of fiber reinforcement, four different fiber lengths (5mm, 10mm,
20mm, and 30mm) and four fiber contents (0.25wt%, 0.5wt%, 1wt%, and 1.5wt%) were
employed to prepare the natural fiber-reinforced CPB (NFR-CPB). A series of mechanical
tests, including semicircular bend (SCB) tests and end-notched disc bend (ENDB) tests,
along with scanning electron microscope (SEM) observations, were conducted on NFRCPB and control CPB (without fiber reinforcement) at 7 days, 28 days, and 90 days. The
results revealed that hemp fiber reinforcement can influence pre-peak behavior and
effectively enhance post-peak resistance. Additionally, the results showed that increasing
the hemp fiber content and length improved the fracture energy, ductility, and fracture
toughness of NFR-CPB. Therefore, the proposed hemp fiber reinforcement approach can
be considered a promising method for CPB technology in deep mining applications. | en_US |
