Experimental Crack Width Quantification in Reinforced Concrete Using Ultrasound and Coda Wave Interferometry.

Area of Science:

• Civil Engineering
• Materials Science
• Non-Destructive Testing

Background:

• Reinforced concrete is a critical infrastructure material.
• Understanding crack formation is vital for structural integrity.
• Non-destructive methods are needed for condition assessment.

Purpose of the Study:

• To investigate tensile behavior and crack formation in reinforced concrete using ultrasound.
• To establish relationships between ultrasonic signals and mechanical parameters.
• To advance the use of coda wave interferometry for infrastructure evaluation.

Main Methods:

• Uniaxial tensile tests on reinforced concrete members with embedded ultrasonic transducers.
• Continuous quantification of mechanical parameters via ultrasonic signal recording and coda wave interferometry.
• Analysis of crack patterns with digital image correlation and reinforcement strain with fiber optic sensors.

Main Results:

• Established a direct proportional relationship between relative ultrasonic velocity change and crack widths during crack formation and stabilization.
• Identified linear correlations between velocity change, average strain, and specimen length in the non-cracked state.
• Significantly enhanced understanding of ultrasonic signal behavior in cracked reinforced concrete.

Conclusions:

• Ultrasonic testing, specifically coda wave interferometry, can effectively monitor crack formation and width in reinforced concrete.
• This method offers a promising approach for non-destructive evaluation of existing infrastructure.
• The findings support the broader application of ultrasonic techniques for structural health monitoring.