Study on the thermal and mechanical properties of steel fibre reinforced PCM-HSB concrete for high performance in energy piles. (3rd October 2022)

• Record Type: Journal Article
• Authors: Cui, Hongzhi; Zou, Jinping; Gong, Zhe; Zheng, Dapeng; Bao, Xiaohua; Chen, Xiangsheng
• Is Part Of: Construction & building materials. Volume 350(2022)
• Publication Date: 2022-10-03
• Subjects: GSHP ground source heat pump -- GHE ground heat exchangers -- PCM phase change materials -- HSB hollow steel ball -- PCM-HSB macro-encapsulated PCM using HSB -- CTE coefficient of thermal expansion; Energy piles -- Steel fibre -- Phase change materials -- Hollow steel ball -- Thermal and mechanical properties; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2022.128822
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Hollow steel ball is used to macro-encapsulate the PCM to obtain PCM-HSB aggregates. PCM-HSBs were incorporated with steel fibres to improve the properties of concrete. The thermal conductivity and compressive strength of PCM-HSB concrete is improved. Fibre reinforced PCM-HSB concrete can ensure potential applications of energy piles. Abstract: In this study, a hollow steel ball (HSB) is used to macro-encapsulate the phase change materials (PCM) to obtain PCM-HSB aggregates. Furthermore, the PCM-HSBs were incorporated with steel fibres to improve the thermal and mechanical properties of concrete. The effect of the volume content (0.35, 0.7, and 1.05 vol%) of the steel fibre and the thickness of HSB (0.3 and 1 mm) on the thermal and mechanical properties of the steel fibre reinforced PCM-HSB concrete was evaluated. The test results demonstrated that the thermal conductivity and compressive strength of the PCM-HSB concrete significantly increased with an increase in the steel fibre content and HSB thickness. The addition of 0.35% steel fibre improved the thermal conductivity of the PCM-HSB concrete by 71% due to the bridge function of the scattered steel fibres in the concrete matrix. However, the thermal conductivity decreased when the high steel fibre content was increased to1.05 vol% due to fibre agglomeration. Moreover, compared with that of the plain PCM-HSB concrete, PCM-HSB concrete with 0.7 vol% steel fibre increased the compressive strength of the concrete by 63%. The proposed fibre reinforced PCM-HSB can significantly improve the heat capacity and bearing capacity of concrete, which can ensure potential applications of energy piles.