Giatec SmartRock (available from Schleibinger) is a rugged mobile-based wireless sensor for monitoring the temperature of concrete from fresh to hardened stage. It also estimates concrete strength based on the maturity concept.
Sensor can be placed in the concrete formwork installed on the rebar before pouring to monitor the temperature of concrete in situ. The continuous measurements are recorded on the sensor memory and can be downloaded any time during the concrete setting and hardeningn onsite using the Android and iOS mobile apps on a smartphone or tablet device.
Knowing the temperature history, the strength of concrete can be extimated using a calibration curve based on the concrete maturity concept as per specifications in the ASTM C1074 standard. This method is well accepted by DOTs, NRMCA, PCA, and ACI in the US, as well as CSA in Canada.
Traditionally, contractors collect the temperature data using wired temperature sensors, calculate the maturity index (or temperature-time factor), and use a calibration curve or estimate the concrete strength. The SmartRock sensor and mobile app together offer an easy tool for data collection and analysis on the job site. The user just needs to enter the mix calibration informations in the SmartRock app and assiggn it to a particular sensor. Then, th real-time strength values would be automatically calculated and shown in the app once the user connects to the SmartRock wireless sensor.
The concrete maturity calibration should be conducted for a particular concrete mixture before the project is started. If this information is provided by the concrete producer or has been previously developed, the user can simply enter the data on the app.
Sensor can be used to monitor the temperature and strength of concrete.
This information can be used for:
| Reading Range | -30 to 80 °C |
| Accuracy | ±1 °C |
| Measurement Frequency | Once every 15 mins. (for 2 month of data) |
| Wirelss Signal Range | up to 12 meters |
| Temperature cable length | 30 cm or 3 m |
| Battery Life | up to 4 months after installation |
| Data Communication and Analyisis |
Free Android & iOS app / Giatec 360 Cloud Dashboard. |
| Standards |
ASTM C1074 (Approved by ACI 318, CSA A23.1, most USDOT specifications) |
Develop Maturity Calibration:
(Please note: This is a simplified quide for your general information. Please refer to detailed instructions in the ASTM C1074 standard specification when conducting the concrete maturity calibration!)
Concrete maturity calibration can be easily developed following the instructions in the ASTM C1074 standard. Users can use SmartRock sensors to facilitate this process. The main required steps are summarized as follows:
The mix calibration is now ready to be assigned to a SmartRock2TM sensor in a project where the calibrated concrete mix is used.
Datum Temperature
The datum temperature is a temperature below which we are assuming concrete does not develop strength. There is a detailed procedure as described in the ASTM C1074 to calculate the datum temperature for a particular concrete mixture. In most cases this temperature is between -10 °C to 0 °C. For simplicity purposes, the datum temperature can be assumed as 0 °C which is a conservative assumption. If you test and measure the datum temperature for concrete mixture, please use it for the "Demo mix" in the calibration stage and then in the date entry of the calibrated mix in the SmartRock app.
