Temperature induced fast-setting of cement based mineral-impregnated carbon-fiber reinforcements for durable and lightweight construction with textile-reinforced concrete
Jitong Zhao, Ameer Hamza Ahmed, Marco Liebscher, George Karalis, Rifat Al Saif, Marko Butler, Viktor Mechtcherine
Abstract
Developing durable and sustainable mineral-impregnated carbon-fiber (MCF) reinforcement system is today an effective measure to solve common service issues of conventional steel or FRP reinforcement in building sector. This study introduces a novel methodology for the design and realization of fast-setting cement based MCF reinforcements via targeted thermal activation. The process involves impregnating continuous yarns with a micro-sized particle cement suspension utilizing custom-built manufacturing equipment. Subsequently, the impregnated yarns undergo controlled heating at moderate temperatures to accelerate the cure process and strength development. Flexural and tensile performance of the MCFs exhibits progressive improvements with longer curing durations (from 2 to 20 h) and higher temperatures (from 40 °C to 60 °C). Enhanced mechanical properties are attributed to advanced hydration reactions and microstructural densification, as proven by thermogravimetric analysis (TGA), mercury intrusion porosimetry (MIP), scanning electron microscopy, isothermal calorimetry and micro-computed tomography (μCT). When heating at 60 °C for 20 h, as-produced MCFs demonstrate optimal tensile strength of 2747 MPa and flexural strength of 482 MPa, with exceptional bond with concrete substrate, comparable to conventional FRPs. The proposed post-treatment shows promising potential for significantly enhancing the flexibility of mineral matrix composites, making them suitable for a wide range of industrial and field applications. • Quick methodology using thermal activation for mineral-matrix composites. • Continuous impregnation of yarns with commercial micro cement. • Rapid strength gain of MCFs in terms of flexural and tensile properties within the first few hours. • Comparable mechanical performance to conventional CFRP. • Satisfactory interfacial bond stength between the thermally-accelerated MCF and concrete matrix.