Laboratory Analysis of Grout and Rock Bolt Interaction Under Freeze-Thaw Effect

Rock bolts are support elements that help rock masses surrounding openings in rock formations to support themselves. These bolts are particularly susceptible to freeze-thaw cycles, especially in areas near the surface within the frost depth in terrestrial climates. This susceptibility can negatively impact the tensile strength of the bolts. To address this issue, the effect of freeze-thaw cycles on the tensile strength of cement-filled rock bolts was investigated. A constant water-to-cement ratio (w/c = 0.4) was maintained for the grout used in the cement-filled rock bolts. Fine sand was added to the cement in varying amounts of 0%, 1%, 2%, 3%, 4%, and 5% by weight. The mixture with 3% sand content, which provided the highest unconfined compressive strength, was selected as the filling material. Dacite-rhyolite was chosen as the rock material. To determine the freeze-thaw behavior of the filling material, compressive strengths were measured after applying 0, 25, 50, and 100 freeze-thaw cycles. These same freeze-thaw cycles were then applied to rock bolts prepared with the selected filling material to observe the effects. After each cycle, the tensile strength and adherence stresses of the cement-filled rock bolts were measured. Laboratory test results indicated that the tensile strength and adherence stress of the cement-filled rock bolts decreased with exposure to freeze-thaw cycles. Additionally, it was observed that the compressive strengths of the filling material and the tensile strength behavior of the rock bolts showed parallel trends in response to the freeze-thaw cycles.

Journal

MINING METALLURGY & EXPLORATION

Year

2025

Volume

42

Issue

6

Pages

3991-4004

ISSN

2524-3462

eISSN

2524-3470

DOI

10.1007/s42461-025-01373-3

WoS UID

WOS:001587268000001