Crack Detection

 

CR Sensor

 

Description

A "CR" sensor monitored the presence of cracks in HMA pavement due to environmental effects. It was intended to break when a crack formed in the HMA. The Crack (CR) sensor is an electrical resistance "tape" mounted between HMA lifts. (Like burglar alarm tape on windows).

 

Manufacturer

Custom made by MnROAD staff.

 

Location and Quantity

CR sensors were installed between lifts in several HMA test cells.

 

Current Status

These sensors did not perform as intended. The tape tended to stretch rather than break, so the moment of a HMA crack forming could not be consistently be determined. These were removed when the HMA cells were reconstructed.

 

MnROAD Database Table

Data was collected and stored in the MnROAD database table: MNR.CR_VALUES