Capacitance-based stress self-sensing effectiveness of a model asphalt without functional component

Capacitance-based self-sensing is shown for the first time on a pitch-based material, which serves as model asphalt. No functional component is involved. Compressive stress (5–1720 Pa) is sensed. The capacitance increases reversibly by ≤1.2% upon unloading. It is linearly related to the stress, with the fractional change in capacitance per unit stress ≤9.3 × 10⁻⁵/Pa. The capacitance change is identically and repeatedly observed for 20 cycles at the same stress amplitude. The resistance decreases reversibly upon unloading, but it is an inferior stress indicator than the capacitance, due to the greater irreversibility tendency and less regular dependence on the stress.