Monitoring of freeze-thaw cycles in concrete using embedded sensors and ultrasonic imaging

Javier Ranz, Sofía Aparicio, Héctor Romero, María Jesús Casati, Miguel Molero, Margarita González
Sensors 14 (2), 2014 2280-2304

This paper deals with the study of damage produced during freeze-thaw (F-T) cycles using two non-destructive measurement approaches—the first approach devoted to continuous monitoring using embedded sensors during the cycles, and the second one, performing ultrasonic imaging before and after the cycles. Both methodologies have been tested in two different types of concrete specimens, with and without air-entraining agents. Using the first measurement approach, the size and distribution of pores were estimated using a thermoporometrical model and continuous measurements of temperature and ultrasonic velocity along cycles. These estimates have been compared with the results obtained using mercury porosimetry testing. In the second approach, the damage due to F-T cycles has been evaluated by automated ultrasonic transmission and pulse-echo inspections made before and after the cycles. With these inspections the variations in the dimensions, velocity and attenuation caused by the accelerated F-T cycles were determined.

Acknowledgments

The Spanish Economy and Competitiveness Ministry supported this research under grants numbers BIA2009-14395-C04-01, TEC2012-38402-C04-03 and IPT-020000-2010-26. Javier Ranz thanks the Spanish Economy and Competitiveness Ministry for the FPI (Spanish initials) grant awarded.