Synergic Effect of Recycled Carbon Fibers and Microfibrillated Cellulose Gel for Enhancing the Mechanical Properties of Cement-Based Materials

• Published in: Gels 2023-12, Vol.9 (12), p.981
• Main Authors: Sambucci, Matteo, Nouri, Seyed Mostafa, Tayebi, Sara Taherinezhad, Valente, Marco
• Format: Article
• Language: English
• Subjects: Blood vessels; Carbon fibers; Cellulose fibers; Cement; Compressive strength; Concrete; Fiber reinforced cements; Fiber reinforced materials; Flexural strength; hybrid fiber-reinforced mortar; Hybrid systems; Hybridization; Mechanical properties; microfibrillated cellulose gel; Microstructure; Mixtures; Mortars (material); Permeability; Porosity; recycled carbon fiber; Reinforced cements; Reinforced concrete; Rheological properties; Short fibers; Sustainability; Synergistic effect; Viscosity; Water absorption; Workability
• ISSN: 2310-2861; 2310-2861
• DOI: 10.3390/gels9120981

A new hybrid fiber blend containing microfibrillated cellulose (MFC) gel and recycled carbon short fiber (RCSF) was implemented for designing fiber-reinforced cement mortars, to further improve the mechanical properties and enhance the sustainability of cement-based materials. The individual impact of single fibrous fillers as well as the synergistic effect of a hybrid fiber system (MFC + RCSF) were investigated in terms of the rheological properties, mechanical strength, and microstructure of the mortars. The results indicated that the workability of fresh mixtures slightly increased after fiber addition. The fibers incorporated alone improved the materials' performance in different ways. The addition of RCSF led to improvements of up to 76% in flexural strength and 13% in compression strength for a fiber content of 0.75 wt.%. However, the addition of carbon fibers led to slight deteriorations in terms of porosity and water absorption. On the other hand, the use of MFC induced a less significant growth in terms of mechanical strength (+14% in flexural strength for 0.75 wt.% of cellulose) but greatly improved the microstructural quality of the mortar, significantly reducing its water permeability. Considering the optimum MFC dosage, MFC+RCSF hybrid mixtures showed positive effects on the mechanical properties and microstructure of the mortar, displaying further improvements in strength, while preserving a lower porosity and water absorption than the control mix.