The use of wireless sensor networks to monitor the setting and hardening processes of self-compacting concrete

Abstract

Traditionally, the study of cementitious materials has been performed using wired sensor technologies. Because these technologies are expensive and difficult to install, the use of wireless sensor networks has gained increasing importance. In this paper, the study of setting and hardening processes for two different types of self-compacting concrete (SCC) using a wireless monitoring system is reported. The monitoring system used to perform such study consists of a wireless sensor network using Cricket motes. These motes were purchased from Crossbow Technologies. For our research, the most important capability of Cricket motes is that they host a transmitter/receiver in the ultrasonic wavelength region. For monitoring the setting and hardening processes, the velocity of the ultrasonic pulse traveling across the material was measured, along with the humidity and temperature values both inside and outside the concrete sample. Multi-hop data transmission techniques were considered to monitor the velocity data. Several experiments were performed at the laboratory. A set of samples were manufactured with two types of SCC, in one type some portland cement was replaced by limestone filler. These specimens were exposed to different curing conditions. Although it was found that the ultrasonic acquisition was not very robust, the wireless sensor networks are an efficient technology for monitoring the early stages of self-compacting concrete. © RILEM 2013.