Pulse-Echo Ultrasonic Verification of Silicate Surface Treatments Using an External-Excitation/Single-Receiver...

Area of Science:

• Materials Science
• Non-Destructive Testing
• Acoustics

Background:

• Surface treatments enhance cementitious material durability.
• Accurate verification of treatment efficacy is crucial for performance.
• Existing methods may be destructive or lack field applicability.

Purpose of the Study:

• To evaluate a non-destructive ultrasonic pulse-echo method for identifying surface treatments on cementitious materials.
• To assess the reliability of time-domain signal parameters in quantifying acoustic changes induced by treatments.
• To develop a field-adaptable protocol for quality control of silicate-based surface treatments.

Main Methods:

• A compact pulse-echo ultrasonic system with a single receiver and external transmitter was employed.
• Backscattered echoes from untreated, lithium silicate-treated, and hexylene glycol-enhanced silicate-treated specimens were analyzed.
• Signal parameters including amplitude, RMS voltage, energy, and duration were extracted.
• Receiver operating characteristic (ROC) analysis quantified discriminative power.

Main Results:

• Excellent classification performance (AUC ≥ 0.96) was achieved for distinguishing treatments involving hexylene glycol.
• Moderate separation (AUC ≈ 0.61) was observed between untreated and standard lithium silicate-treated specimens.
• Optimal cut-off values yielded sensitivity and specificity exceeding 96% in best-case scenarios.

Conclusions:

• A single-receiver, one-sided pulse-echo ultrasonic approach is effective for quality control of silicate surface treatments.
• The method is rapid, cost-effective, and suitable for on-site application.
• This study bridges the gap between laboratory ultrasonic characterization and practical field verification of surface treatments.