Tensile properties and microstructure of lightweight engineered geopolymer composites containing PVA fibers and multi-walled carbon nanotubes (MWCNTs) after high-temperature exposure

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials Pub Date : 2025-04-02 DOI:10.1016/j.conbuildmat.2025.141154

Xinyu Chen , Hui Xiang , Shan Li , Zhijun Cheng

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引用次数: 0

Abstract

This study investigates the effects of elevated temperatures on the properties of lightweight engineered geopolymer composites (LW-EGC). The LW-EGC was reinforced with 2.5 % polyvinyl alcohol (PVA) fibers and 0.15 % multi-walled carbon nanotubes (MWCNTs) and subjected to temperatures ranging from 20 °C to 800 °C. Performance evaluations included measurements of mass loss, tensile strength, crack formation, and microstructural evolution using thermogravimetric analysis (TG), tensile tests, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). Results revealed that LW-EGC exhibited progressively greater mass loss as temperature increased, though the mass-loss rate gradually decreased due to the evaporation of water and decomposition of calcium-rich phases. Tensile strength reached a maximum at 200 °C but decreased significantly beyond 400 °C, mainly due to the melting of PVA fibers and increased matrix porosity. SEM analyses showed extensive decomposition of PVA fibers and progressive degradation of the geopolymer matrix at higher temperatures, weakening the overall composite structure. XRD and FT-IR analyses confirmed calcite decomposition and highlighted the excellent thermal stability of N(C)-A-S-H gel.

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来源期刊

Construction and Building Materials 工程技术-材料科学：综合

CiteScore

13.80

自引率

21.60%

发文量

3632

审稿时长

82 days

期刊介绍： Construction and Building Materials offers an international platform for sharing innovative and original research and development in the realm of construction and building materials, along with their practical applications in new projects and repair practices. The journal publishes a diverse array of pioneering research and application papers, detailing laboratory investigations and, to a limited extent, numerical analyses or reports on full-scale projects. Multi-part papers are discouraged. Additionally, Construction and Building Materials features comprehensive case studies and insightful review articles that contribute to new insights in the field. Our focus is on papers related to construction materials, excluding those on structural engineering, geotechnics, and unbound highway layers. Covered materials and technologies encompass cement, concrete reinforcement, bricks and mortars, additives, corrosion technology, ceramics, timber, steel, polymers, glass fibers, recycled materials, bamboo, rammed earth, non-conventional building materials, bituminous materials, and applications in railway materials.