Behavior of CFRP-Confined Sand-Based Material Columns under Axial Compression.

Guodong Li,Haitian Yan,Wentao Deng,Hongzhi Wang,Honglin Liu

doi:10.3390/polym13223994

Abstract

This paper presents an innovative pumpable standing support designed for underground mines located in the arid and semi-arid deserts of the Gobi region with a shortage of water resources. The exterior shell of this pumpable standing support is made of carbon fiber-reinforced polymer (CFRP), while the infill material is a sand-based material (SBM). As the novel backfill material, SBM is the combination of high-water cementing material and desert sand. A series of experimental tests were conducted to obtain the mechanical response mechanism of this novel pumpable standing support under uniaxial compression. Test variables investigated in this research covered the water-to-powder ratio of the cementing material, the mixing amount of sand, and the thickness of the CFRP tube. Test results confirmed that the CFRP-confined SBM columns exhibited typical strain hardening behavior with the acceptable axial deformation. It was also demonstrated that using high-strength cementing material, a thicker CFRP tube, and a high mixing amount of sand effectively increased the bearing capacity of the CFRP-confined SBM column. Except for the exemplary structural behavior, the consumption of high-water cementing materials of the novel pumpable standing support is smaller than that of its counterparts made of pure cementing material, when specimens with the same mechanical performance are compared.

Highlights

Complex production demands and challenging geological conditions in underground mining have severely impacted the stability control of roadways surrounding rocks [1]
Many studies have pursued the first use of the pumpable support system in roadways of longwall faces in the United States regarding its mechanical performance [7,8,9]
A novel column designed to maintain the stability of surrounding rock underground, termed carbon fiber-reinforced polymer (CFRP)-confined sand-based material (SBM) column, was developed

Summary

Introduction

Complex production demands and challenging geological conditions in underground mining have severely impacted the stability control of roadways surrounding rocks [1]. The combination of active and passive supports for surrounding rock control in the roadway is of high importance for ensuring the stability of surrounding rocks in underground mines [2,3]. Passive supports ( known as the auxiliary support system) are commonly used for the stability control of roadways surrounding rocks in underground mining, mainly including timber piles, prop walls, concrete blocks, and reinforced concrete columns [4,5]. Scientific research and field practice have shown that the compressive performance of the pumpable supports was related to the mechanical performance of the material filling the supports and the performance of the shell. Due to the limited rigidity and strength of the shell [7], the pumpable supports will lose their bearing capacity after the filling material reaches its peak strength [6,8,10,11]

Results

Discussion

Conclusion