Better Roads Digital Magazine
Issue link: https://read.dmtmag.com/i/85926
RoadScience Piezoelectricity describes an electric charge that is developed within a crystalline or ceramic material when that material is stressed, moved or disturbed. Their proposed smart aggregate is formed by embedding a water- proof piezoelectric patch with lead wires into a small concrete block. These proposed smart aggregates are multi-functional and can perform three major tasks: early-age concrete strength monitoring, impact detection and structural health monitoring. The smart aggregates would be embedded into the desired location before the casting of the concrete structure. The concrete strength development is monitored by observing the high- the ability to communicate via wireless connections to various forms of readout systems. frequency harmonic wave response of the smart aggregate. Impact on the concrete structure is detected by observing the open-circuit voltage of the piezoceramic patch in the smart aggregate. But smart aggregate sensors need the ability to communicate via wireless connections to various forms of readout systems. Many applications for sen- sors are in remote and embedded locations where wired or optical connec- tions are not practical or economical, reports Johns Hopkins University. Sensors in these appli- cations need to be small, rugged and Smart aggregate sensors need long-lived. Support platforms need to be able to adapt to a large variety of sensors including pressure, temperature, conductivity and analytical. The Johns Hopkins University Applied Physics Laboratory has developed and patented the Wireless Embedded Sensor Platform (WESP). The initial application for this technology was a program that embedded the sensor, transducer and communication system in concrete to measure the corrosion of rebars. The WESP is small (about the size of a quarter), rugged (made of high compression strength ceramics) and versatile (capable of being integrated with a wide variety of sensor elements), long lasting (no battery), and wireless. A remote transmitter powers the WESP up from a sleep mode, the sensor readings are converted in the WESP and transmitted to a receiver, and once the measurement is made the unit goes back to sleep until the next request is made. Most Affordably Priced Feature Rich Speed Feedback Sign! Write 141 on Reader Service Card or visit www.betterroads.com/info Better Roads July 2012 27