Performance of Self-Sensing Cement-Stabilized Sand under Various Loading Conditions

Area of Science:

• Materials Science
• Civil Engineering
• Nanotechnology

Background:

• Piezoresistive behavior of self-sensing cementitious composites is influenced by multiple factors.
• Limited research exists on how loading conditions affect self-sensing cement-stabilized composites' sensitivity.

Purpose of the Study:

• To investigate the effect of loading conditions on the electromechanical performance of self-sensing cement-stabilized sand.
• To analyze the influence of loading location and stress level on sensitivity.
• To understand the microstructural mechanisms behind observed electromechanical behaviors.

Main Methods:

• Determined the percolation threshold of cement-stabilized sand with multiwall carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs).
• Tested specimens under cyclic compressive stresses, varying electrode placement and load levels.
• Utilized scanning electron microscopy (SEM) for microstructural analysis.

Main Results:

• Electrode location relative to the loading area significantly impacts sensitivity; optimal sensitivity occurred when electrodes were directly beneath the load.
• Stress sensitivity of the self-sensing material increased proportionally with the applied stress level.
• SEM revealed that loading conditions alter carbon nanomaterial bridging, affecting electromechanical responses.

Conclusions:

• Loading conditions are critical parameters for designing effective self-sensing cement-stabilized sand.
• Optimizing electrode placement and understanding stress-sensitivity relationships are vital for field applications.
• Microstructural changes under load explain the observed electromechanical variations.