German company ConcR GmbH has launched a smart building material monitoring solution that analyzes the physical attributes of concrete as it dries and “matures”, to check when it is safe to proceed with the next stage of construction. The solution provides data across the life cycle of cementitious building materials like concrete and screed starting from construction until 25 years in operation, enabling data centric insight within each lifecycle phase for planners, engineers, contractors, and owner-operators.
The ‘ConcR Sensors’ are attached to a rebar (a reinforcing steel bar used to strengthen concrete slabs) before the concrete is poured. The sensors are connected to the ‘ConcR Box’, which sends the data – collected every ten minutes – directly to the Cloud. This solution can record temperature, relative humidity, residual moisture, pH and chloride levels, providing key insights into the strength and durability of the cement or concrete.
“These physical attributes are vital from a civil engineering perspective,” says Burak Acilan, Founder and CEO at ConcR GmbH. “Without the validation that the concrete poured on-site meets the required technical specifications, construction cannot proceed. This makes ConcR solution ideal not only for quality monitoring, but also for project management.”
Direct Cloud connectivity
The ConcR Box is powered by Nordic Semiconductor’s nRF9160
low power SiP. The multimode LTE-M/NB-IoT modem with integrated RF Front End (RFFE) enables the nRF9160 SiP to transmit the sensor data directly to the Cloud. The nRF9160 SiP’s LTE modem supports both SIM and eSIM, offers 700 to 2200 MHz LTE band support, 23 dBm output power, -108 dBm RX sensitivity in LTE-M, and -114 dBm RX sensitivity in NB-IoT mode. The RF performance of the ConcR solution is optimized to achieve maximum range, critical in construction environments characterized by substantial concrete and cement structures, which typically pose significant signal attenuation challenges.
Once the data has been sent to the Cloud, it can be accessed using the ‘ConcR Insights’ web dashboard or mobile app, which provide both data visualization—using histograms to show the progression of each metric over time—and data analytics. By analyzing this data, the platform can provide important insights into metrics such as the evolution of concrete strength, and provide automated notifications when metrics surpass specified levels. It also allows users to manage their ConcR sensors and assign ConcR devices.
The solution can achieve a battery life of over two-and-a-half years, using Li-SoCl2 batteries, thanks, in part, to the class-leading power consumption of the nRF9160 SiP. The SiP supports both PSM and eDRX power saving modes. For both LTE-M and NB-IoT the PSM floor current is as low as 2.7 µA, and with an eDRX interval of 655 s the average current is 6 µA for LTE-M and 9 µA for NB-IoT.
Superior RF sensitivity
“In addition to its low power consumption, and the power conservation enabled by the PSM and eDRX modes, we also selected the nRF9160 SiP due to the incredible RF sensitivity, which we found to be superior to that of competitive solutions,” says Maysam Ibraheam, Head of Engineering at ConcR GmbH. “The support for both NB-IoT and LTE-M was beneficial, as was having a chip that included both a processor and modem in one small package.
“The technical support from Nordic was invaluable at every stage of our development process. Nordic's engineers offered insightful suggestions that helped lower the power consumption of our solution. We also benefited greatly from the Nordic DevZone and the extensive library of supporting articles.”