Guofu Qiao

Concrete, in particular application scenarios, such as crack repair, disaster rescue and relief, and 3D printing, needs to be cured quickly. In this work, a novel synthesis strategy, UV‐initiated frontal polymerization (FP), for fast preparation of high‐strength polymer concrete at room temperature is proposed, and the whole fabrication progress within several minutes, in which coarse aggregates and a small amount of short carbon fibers (CF) are used to enhance mechanical properties and heat conduction and reduce the amounts of chemical adhesives. SEM, DSC, MIP, Ultra depth of field microscope, and Rheometer are employed to characterize the properties of chemical adhesives, polymer concrete, and polymerization process. In addition, the finite element method is used to investigate the internal temperature field status of the FP process. The results indicate that the compressive and flexural strengths of the polymer concrete with 1.0 wt%‐1 mm‐CF‐50 vol.%‐quartz sand exceeded 70 and 20 MPa, respectively, in which the average self‐propagation velocity reached 58 mm min⁻¹. The investigation provides a promising approach for the rapid construction of structural facilities, emergency repair after disasters, 3D printing concrete, etc.

Hydrogels are formed through the cross-linking of hydrophilic polymer chains within an aqueous microenvironment. A novel synthesis strategy, UV-initiated frontal polymerization to quickly synthesize bubble-free, self-propagating hydrogel anticorrosive coatings in aqueous conditions, was presented, in which the self-propagating polymerization rate reached 16.7 mm min^-1. SEM, AFM, FTIR, EIS, IC, XPS, and ultra-depth-of-field microscopy were used to characterize the surface morphology and anti-corrosion properties of the hydrogel coating. The addition of nano-SiO₂ formed dense hydrogen bonds, and the stability of the three-dimensional network was enhanced. Underwater, the hydrogel coating could physically block corrosive media from reaching steel surfaces, and it was 75% effective at blocking chloride ions after 7 days under osmotic pressure. In addition, 1,2,4-triazole accumulated on the steel surface, and then the active anti-corrosion function took effect. This paper provides the basis for the in situ synthesis of hydrogel anticorrosive coatings on the surface of mild steel in a wet or underwater state.

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. We also conducted test-bed experiments based on RC panels. The results verify the feasibility and efficiency of the proposed WSN system and algorithms.