Smart Concrete Using Optical Sensors Based on Bragg Gratings Embedded in a Cementitious Mixture: Cure Monitoring and...

Area of Science:

• Materials Science
• Civil Engineering
• Sensor Technology

Background:

• Smart concrete integrates sensing and structural functions for improved construction.
• Inadequate concrete curing can lead to shrinkage cracks and reduced mechanical strength.
• Monitoring concrete curing is crucial for structural integrity and performance.

Purpose of the Study:

• To develop a single measurement system using fiber Bragg grating (FBG) sensors for monitoring concrete curing parameters.
• To evaluate autogenous shrinkage strain, temperature, and relative humidity (RH) during the concrete curing process.
• To assess the performance of embedded FBG sensors in a smart concrete structure under load.

Main Methods:

• Utilized fiber Bragg grating (FBG) sensors to measure autogenous shrinkage strain, temperature, and relative humidity (RH).
• Employed K-type thermocouples as reference temperature sensors.
• Embedded FBG strain sensors in concrete specimens for monitoring during a simulated beam bend test.

Main Results:

• The system accurately measured maximum autogenous shrinkage strains (up to 213.64 με) and relative humidity (up to 98.20 %RH).
• Recorded maximum temperatures reached 63.65 °C using FBG sensors.
• FBG sensors maintained signal integrity throughout load cycles in the bend test, measuring strains up to 123.71 με.

Conclusions:

• The developed FBG sensor system effectively monitors key concrete curing parameters in real-time.
• The system enables the transformation of conventional concrete structures into smart structures with integrated sensing.
• This technology offers significant potential for improving concrete design, construction, and long-term structural health monitoring.