The workability, compressive strength, flexural strength, and electrical conductivity of smart high-performance concretes containing graphite and steel fiber
Tóm tắt
Smart high-performance concretes (SHPCs) containing highly electrically conductive functional fillers (FFs) were a new type of material to apply for structural health monitoring systems or smart city infrastructures. This study investigated the mechanical properties, such as the compressive strength, flexural strength, and the electrical resistivity of SHPCs incorporating graphite powder (0 to 5% of cement by weight) and steel fibers as FFs (0 to 2 vol%). The electrical resistivity of each specimen was measured using a direct current (DC) with the two-probe method to evaluate the conductivity of SHPCs. The results indicated that the addition of graphite decreased the workability, compressive, and flexural strengths but notably increased the electrical conductivity of SHPCs. The SHPCs containing 5% graphite and 1 vol% steel fibers produced the highest compressive strength (72.8 MPa) and flexural strength (14.7 MPa) in comparison with SHPCs containing 5% graphite and other fiber contents. As the fiber volume content increased from 0 to 2 vol%, the volume weight of SHPCs varied from 2216 to 2363 kg/m3. The flexural strength per compressive strength of SHPCs was varied from 18.7 to 20.1%. In addition, the electrical conductivity of the SHPCs showed a notable increase with higher contents of graphite and steel fibers, forming effective conductive networks within the concrete matrix. The findings suggest that the integration of graphite and steel fibers can effectively improve the multifunctional performance of SHPCs, making them suitable for structural health monitoring applications in advanced civil infrastructure.
