The RFID technology in the construction environment is getting a lot of attention; it has been proven to make the project more productive by saving time and dollars for the overall project.  Use of RFID technology to monitor the internal temperature of placed concrete provides real time information at the construction site.  If the only requirement is to monitor temperature at various locations of a mass pour the HardTrack System is by far the best equipment available.

The use of non-destructive wireless tags isa easier, faster, safer, and more productive than other maturity methods or devices and the same can be said of the various destructive methods of determining concrete maturity.  It has been proven by using concrete maturity the production of concrete test cylinders can be reduced by 60% to 80%.  Projects move forward on the average of 1 - 2 days faster per pour using concrete maturity, knowing the in-place concrete early age strength  - real time.  

The RFID Tags with the temperature sensor and data logger are available in two styles.  The tag used most often is buried in the concrete up to a maximum depth of 8 inches.  The second tag has an external sensing device that will allow the tag to be buried near the surface (3 – 4 inches deep).   The external sensor is then buried to the required depth, restricted only by the length of the cable; the standard external cable is one meter in length.  The second option for the tag with the external sensor is to only imbed the cable leaving the tag exposed; the tag can then be reused.  Both are iQ32T tags that will store 13, 312 data points.  The user definable intervals range from 1 minute up to one measurement every 18 hours, with a software default of 30-minute intervals.  The tag operating temperature range is from – 40 degrees C to + 80 degrees C.  The external probes will read temperatures from -127 C to +127 C.  Temperature is recorded with an accuracy of +/- 0.5 C and stored on the tag.   Each tag contains a unique serial number (tag ID) that is used to communicate with only one sensor (tag) at a time.

The software is user friendly and allows for the following user definable preferences; Temperature Celsius or Fahrenheit, Pressure (strength) MPa or PSI, Maturity methods, Nurse-Saul (Time Temp Factor) or Arrhenius (Equivalent Age).  The detailed temperature log is downloadable into an Excel Spreadsheet for quality assurance documentation. 

This product is currently in use on waste water treatment plant near Grand Rapids, Michigan and by the Port of Authority NY & NJ on the Freedom Tower construction.