Synthesis of a chitosan-based superabsorbent polymer and its influence on cement paste.

To address the challenge of adaptability between cement-based materials and conventional superabsorbent polymers (sodium polyacrylate, Na-PA), a chitosan-based superabsorbent polymer (CSP) with high salt and alkaline resistance was synthesized, and the optimal synthesis process was determined by a single-factor method. The macroscopic performance and microstructure of CSP and Na-PA were compared, and their influences on cement paste were studied. The results show that CSP exhibits a gradual swelling process during water absorption, which is independent of the solution environment.

Corrosion in reinforced concrete panels: wireless monitoring and wavelet-based analysis.

To realize the efficient data capture and accurate analysis of pitting corrosion of the reinforced concrete (RC) structures, we first design and implement a wireless sensor and network (WSN) to monitor the pitting corrosion of RC panels, and then, we propose a wavelet-based algorithm to analyze the corrosion state with the corrosion data collected by the wireless platform. We design a novel pitting corrosion-detecting mote and a communication protocol such that the monitoring platform can sample the electrochemical emission signals of corrosion process with a configured period, and send these signals to a central computer for the analysis. The proposed algorithm, based on the wavelet domain analysis, returns the energy distribution of the electrochemical emission data, from which close observation and understanding can be further achieved.