Pavement undergoes a process of deterioration resulting from repeated traffic and/or environmental loading. By detecting pavement distress and damage early enough, it is possible for transportation agencies to develop more effective pavement maintenance and rehabilitation programs and thereby produce significant cost and time saving. Structural Health Monitoring (SHM) has been conceived as a systematic method for assessing the structural state of pavement infrastructure systems and documenting their condition. Over the past several years, this process has traditionally been accomplished through the use of wired sensors embedded in bridge and highway pavement. However, the use of wired sensors has limitations for long-term SHM and presents other associated cost and safety concerns. Recently, Micro-Electromechanical Systems (MEMS) and Nano-Electromechanical Systems (NEMS) have emerged as advanced/smart-sensing technologies with potential for costeffective and long-term SHM. To this effect, a study has thus been initiated to evaluate the off-the-shelf MEMS sensors and wireless sensors, identify their limitations, and demonstrate how the acquired sensor data can be utilized to monitor and assess concrete pavement behavior. The feasibility of implementing a wireless communication system into a MEMS sensor was also investigated. Off-the-shelf MEMS sensors and wireless sensors were deployed in a newly constructed concrete highway pavement. During the monitoring period, the temperature, moisture, and strain profiles were obtained and analyzed. The monitored data captured the effects of daily and seasonal weather changes on concrete pavement, especially, early-age curling and warping behavior of concrete pavement. These sensors, however, presented

Health monitoring of pavement systems using smart sensing technologies

Pavements tend to deteriorate with time under repeated traffic and/or environmental loading. By detecting pavement distresses and damage early enough, it is possible for transportation agencies to develop more effective pavement maintenance and rehabilitation programs and thereby achieve significant cost and time savings. The structural health monitoring (SHM) concept can be considered as a systematic method for assessing the structural state of pavement infrastructure systems and documenting their condition. Over the past several years, this process has traditionally been accomplished through the use of wired sensors embedded in bridge and highway pavement. However, the use of wired sensors has limitations for long-term SHM and presents other associated cost and safety concerns. Recently, micro-electromechanical sensors and systems (MEMS) and nano-electromechanical systems (NEMS) have emerged as advanced/smart-sensing technologies with potential for cost-effective and long-term SHM. This two-pronged study evaluated the performance of commercial off-the-shelf (COTS) MEMS sensors embedded in concrete pavement (Final Report Volume I) and developed a wireless MEMS multifunctional sensor system for health monitoring of concrete pavement (Final Report Volume II).

https://rosap.ntl.bts.gov/view/dot/32872/dot_32872_DS1.pdf

Development of a Wireless MEMS Multifunction Sensor System and Field Demonstration of Embedded Sensors for Monitoring Concrete Pavements, Volume II

This study assesses hydration, rheology, and sorptivity of cementitious pastes using relatively low-cost Arduino-based platforms with integrated sensors. The prime objective is to develop a correlation between conventional apparatus-based and Arduino-integrated sensor-based assessment. A total of six samples of cementitious paste were prepared at a room temperature of 26°C, with a w/b ratio of 0.3, containing cement, fly ash, and silica fume. First, the conventional apparatus was employed to assess hydration, rheology, and sorptivity of cementitious mixes. Afterward, a platform arranged for data acquisition, comprising Arduino Mega 2560, a temperature sensor, a soil moisture sensor, and a voltage supply, was used to assess the same properties. The recorded temperature and moisture content data were transmitted using the Android application and the Wi-Fi modem router. A 5-minute moisture analysis test was conducted to monitor the rheological behavior of cementitious mixes. The heat of the hydration mechanism was evaluated for 32 hours using a temperature sensor, enabling continuous and real-time monitoring. Moreover, a sorptivity test on cube samples was performed using shielded self-based apparatus in an adiabatic condition, resulting in relatively long-term monitoring. The microscopic details are analyzed by using a scanning electron microscope (SEM) in conjunction with EDX analysis. Thus, the potential application of the inexpensive sensor-based method is verified.

Assessment of Hydration Mechanisms, Rheological Behavior, and Sorptivity of Portland Cement Pastes Using Low-Cost Arduino Platform-Based Sensors

This thesis presents a study of wireless sensor networks applied in monitoring the curing process of concrete building structure. To replace the massive user intervention of the traditional monitoring methods with automated data acquisition, various types of sensors are developed for different concrete tests, including compressive strength measurement, maturity test, and relative humidity test. The main purpose of the thesis is to provide an analysis of existing commercial sensors as well as research prototypes, comparing different test methods and communication models. Distribution of sensors, future potential in millimeter-wave, and simulation environments are also discussed.

Xiaotao Wang

Papers

Study of Sensor Network Applications in Building Construction