| dc.description.abstract | Due to the rapid strength acquisition rate, relatively high solid content, and sustainable reuse of
waste tailings, cement paste backfill (CPB) technology has gradually become a standard practice
in underground mining operations. To improve the engineering behavior and performance of CPB
materials, fiber-reinforced CPB (FR-CPB) has attracted increasing interest over the past decade.
The application of fiber reinforcement can improve the mechanical properties, including the
material strength and ductility, and enhance post-peak resistance. However, the successful
implementation of fiber reinforcement requires the full consideration of field curing conditions.
After placement into underground mined-out voids (called stopes), the massive backfill structure
(with a backfilling height of tens to hundreds of meters) yields a high-level curing pressure under
the gravity effect, which accompanies the development of microstructure and macroscale
mechanical properties of backfill materials from early to advanced ages. Therefore, to accurately
assess the development of mechanical properties and behaviors of FR-CPB, it is essential to fully
consider the effect of curing pressure. Moreover, the previous studies focus mainly on the
conventional geomechanical behaviors, including compressive, tensile, and shear behaviors, of
FR-CPB materials based on the elastoplastic theory. As a result, the previous studies aim to
correlate the permanent deformation and material degradation and thus evaluate and design
backfill materials for their engineering applications. However, as a type of cementitious material,
the brittle response and the associated catastrophic failure of the CPB matrix are governed by the
crack growth. Through crack propagation and coalescence, the degradation of mechanical
properties occurs and may lead to material failure at the macroscale. [...] | en_US |
