Smart Cement-Based Materials Reinforced with CNT-Grafted CFs: Preparation and Performance Evaluation

Area of Science:

• Materials Science
• Civil Engineering
• Nanotechnology

Background:

• Smart cement-based materials offer potential for structural health monitoring.
• Conductive fillers improve composite performance but face dispersion challenges.
• Carbon nanotubes (CNTs) and carbon fibers (CFs) are key conductive materials.

Purpose of the Study:

• To develop a novel CNT-CF-incorporated cementitious composite (CNT-CF/CC) for enhanced structural monitoring.
• To improve the dispersion and performance of conductive fillers in cement composites.
• To investigate the conductivity, sensitivity, and mechanical properties of the developed composite.

Main Methods:

• Grafting CNTs onto CF surfaces using a coupling agent method to create CNT-CFs.
• Incorporating CNT-CFs into a cementitious composite (CNT-CF/CC).
• Utilizing Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) for material analysis.

Main Results:

• CNT-CF/CC exhibited significantly enhanced conductivity and piezoresistivity compared to CF/CC.
• The composite demonstrated stable performance and a broad measurement range under varying temperatures and humidity.
• Mechanical properties were improved, with a failure load of 25 kN and a maximum FCR of 24.77%.

Conclusions:

• The CNT-CF/CC offers a promising solution for structural health monitoring with superior performance.
• The improved conductivity and sensitivity are attributed to CNTs and enhanced filler dispersion.
• The strong interfacial connection between CNT-CFs and the cement matrix ensures stable performance.