The Failure Mechanical Properties of Cemented Paste Backfill with Recycled Rubber

Abstract

Understanding the mechanical properties and failure process of cemented paste backfill with recycled rubber (RCPB) is the foundation of backfill design in underground mining. In this study, physical and mechanical tests were conducted on RCPB to obtain its mechanical property parameters, such as its uniaxial compressive strength (UCS), toughness, and peak strain. The influence of the rubber dosage on the mechanical properties of RCPB was also analyzed. In addition, the deformation behavior, fracture development, and failure process of RCPB with different rubber contents were observed using the digital image correlation (DIC) technique. The experimental results suggested that, although the UCS of RCPB is reduced as more rubber is added, its toughness and ability to absorb energy is increased. Moreover, the impact resistance of RCPB is improved by this increased toughness. With the increase in the rubber content, the deformation corresponding to the plastic yield stage of RCPB increased, which resulted in better ductility and improved impact resistance. The failure of the RCPB specimens mainly showed an “X” shape. The results of this study help us to better understand the mechanical behavior of RCPB after backfilling underground.

Dynamic Loading Characteristics of Cemented Paste Backfill with Recycled Rubber

“…They found that adding 0.6 wt% RTPF to a CTB yielded a comparable mobility and strength to an enhanced CTB with 0.3 wt% PPF, while reducing costs and improving sustainability. With the rapid development of the auto industry, the environmental issues caused by discarded automotive tires, known as "black pollution," urgently need to be addressed [14][15][16]. Recycled rubber is the main means to solve the issue of discarded tires.…”

Polypropylene Fiber Effect on Flexural Strength, Toughness, Deflection, Failure Mode and Microanalysis of Cementitious Backfills under Three-Point Bending Conditions

“…Many scholars and engineers have so far performed numerous investigations on CTB's toughness improvement [31,32]. The main method to enhance the toughness of CTB materials is to incorporate different additives such as straw [33], rubber [34], fiber [32], sand [35], and others [36,37]. Researchers have improved the crack resistance and toughness of engineering specimens by adding hybrid fibers to CTB (i.e., strengthening fill's strength features and enhancing the material's stress-crack rupture link, [38][39][40]).…”