Details

Geopolymer concrete (GPC) is a sustainable low-carbon alternative to ordinary Portland cement with high chemical durability and inherent thermal stability. But it is often limited to structural applications because it is inherently brittle and has a low tensile strength. Steel fibre reinforcement can effectively overcome these problems. The paper presents a detailed numerical study on the thermal and mechanical behaviour of steel fibre reinforced geopolymer concrete , using a verified 3D meso- scale finite element model in Abaqus. The analysis was carried out using Concrete Damaged Plasticity model for the geopolymer matrix and discrete truss elements for randomly distributed steel fibres at volume fractions of 0%, 0.5%, 1.0% and 1.5% under ambient mechanical loading. The main findings indicate that steel fibre reinforcement fundamentally enhances structural performance: compressive strength was increased by up to 17.9% and splitting tensile strength by 144.8% under ambient conditions, and the failure mechanism was changed from brittle crushing to pseudo-ductile, fiber-bridged cracking. The thermal analysis shows that the steel fibers serve as internal conductive networks, improving the core heating up to 45.0% and greatly decreasing the through-thickness thermal gradients up to 41.8%, which alleviates the self-restraint thermal stresses. Most importantly, under simultaneous thermo-mechanical flexural loading (200°C–800°C), plain GPC suffered catastrophic brittle collapse at residual loads of ~2.85–3.0 kN for temperatures ≥400°C, while 1% SFGPC maintained a stable load-bearing capacity up to 15 kN even at 800°C.

• Министерство науки и высшего образования Российско
• Санкт-Петербургский политехнический университет Пе
• Инженерно-строительный институт
• Министерство науки и высшего образования Российско
  • ЗАДАНИЕ
  • на выполнение выпускной квалификационной работы
• Ministry of Science and Higher Education of the Ru
• Institute of Civil Engineering
  • THE TASK
  • for the completion of the final qualifying work