Performance investigations on fluorine-rubber-tube-laying pumping wet shotcrete filled with microencapsulated phase change materials

Abstract

The challenge of mitigating adverse climatic conditions is a critical issue that affects worker safety and operational efficiency in underground engineering. This study introduces an innovative approach using pumping wet shotcrete as an insulating material, incorporated with microencapsulated phase change materials (MPCMs) and filled within fluorine rubber tubes to address this concern. The MPCMs were synthesized via suspension polymerization, utilizing paraffin as the core material and modified SiO2-poly (lauryl methacrylate) as the shell material. To determine the optimal composition for practical application, an orthogonal experimental design was employed, complemented by comprehensive performance testing. The results indicated that a mix of 1375 kg/m3 of sand, 120 kg/m3 of ceramsite, and 1 g/cm of SiO2-MPCMs in each fluorine rubber tube having an inner diameter of 13 mm, provided the best balance between multiple properties. Notably, the insulation performance improved by 60–75 % compared to traditional pumping wet shotcrete, demonstrating a significant enhancement in thermal management capabilities. The findings contribute substantially to the field of thermal management in mines, presenting a novel technique that could be instrumental in improving safety and efficiency in deep underground operations.

Keywords

• Tube-laying
• Pumping wet shotcrete
• Fluorine rubber tubes
• Microencapsulated phase change materials
• Orthogonal experimental design