Non-contact viscosity detection for cement slurry using laser scanning of wave motion under rod impact

• Published in: Construction & building materials 2024-09, Vol.443, p.137709, Article 137709
• Main Authors: CUI, Hongzhi, CAO, Lele, CAO, Xiangpeng
• Format: Article
• Language: English
• Subjects: In-line detection; Laser profiler; Non-contact detection; Rheology; Viscosity
• ISSN: 0950-0618
• DOI: 10.1016/j.conbuildmat.2024.137709

Concrete workability was typically assessed using slump tests and viscometers, which involved contact-based measurements and required sampling, making them unsuitable for online measurements. This study proposed a non-contact inspecting approach by utilizing a laser profiler to scan the mixture surface height changes at high speed and high resolution when the mixture was impacted by a free-fall rod. The energy transfer efficiency was defined to analyze the energy transferred from the rod kinetic energy to the mixture waving energy, and the mechanism between the material hydration and the surface dynamic response was revealed. The maximum wave peaks, waveform areas, and energy transfer efficiencies were extracted as critical features and established a robust correlation with the mixture viscosity with R2 of 0.945, 0.919, and 0.949 correlation with the viscosity, respectively, proving that the proposed approach can be utilized in the in-line liquid material inspection. This study demonstrated the laser scanning method as a simple and effective approach, providing the possibility of non-contact detection to characterize the rheological properties by analyzing the surface fluctuations. •A non-contact rapid detecting approach for the liquid viscosity was invented.•The surface fluctuation was characterized in detail by the laser profiler.•The mechanism between the material hydration and the surface response was revealed.•The energy transfer efficiency reflected the slurry hydration degree and viscosity.•A robust correlation between the viscosity and the eigenvalues was established.