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• Ceramic waste slag-based lightweight aggregate services well after 14 years' curing. • Chloride ion permeability level of 14-year-old LWAC is very low. • Enhanced interfacial transition zone is observed in LWAC with CLWA. • Consuming ceramic waste slag in LWAC is feasible and effective. Lightweight aggregate concrete (LWAC) characterized with low dead weight and high performance, has been applied widely in concrete structures in the past two decades. Mostly, LWAC components play a crucial role in reducing structural weight and keeping structures in good service condition. However, long-term properties of LWAC, especially those prepared with industrial waste-based aggregate, directly affect the durability of structure but have not been explored yet. In the present study, 14-year LWAC incorporating with ceramic waste-based lightweight aggregate (CLWA) were experimentally studied. Traditional LWAC with furnace slag lightweight aggregate (FLWA) was designed as a contrast. Properties of 14-year LWAC such as compressive strength, chloride ion permeability, X-ray diffraction and open porosity were evaluated. In addition, high magnification electron microscope, scanning electron microscope and energy dispersive spectroscopy (SEM-EDS) were adopted to characterize the interfacial transition zone (ITZ) and microstructure of LWAC. Results indicates that after 14 years' curing, no strength reduction is detected and the chloride ion permeability maintains in very low level for LWAC. Long-term performance of LWAC with CLWA is superior to that with FLWA, thanks to the disconnected uniform pores/rough particle surface distributed in CLWA and the compact ITZ between aggregates and mortar. [ABSTRACT FROM AUTHOR]

• The STL curve of the FMPPs has a distinct resonance peak. • Low bending stiffness results in poor sound insulation effects. • The STL curve remains unchanged when the arrangement order transposed symmetrically. • Decreasing the perforation rate decreased from the sound source side is beneficial to improve the absorption effect. It is unlikely to ignore the coupling effect between the structure of the micro-perforated panel (MPP) and the water medium during the application of MPP in the water medium. Theoretical and experimental studies on the sound transmission characteristics of multi-layer flexible micro-perforated panels (FMPPs) under normal incidence conditions were performed. The transfer impedance of finite-sized FMPPs was calculated with the modal superposition method, and the transmission and energy dissipation factor of the FMPPs was derived using the transfer matrix method. Besides, the studies on the effect of panel elastic properties and the arrangement order on the sound insulation performance were carried out. The sound transmission loss (STL) curve remains unchanged when the arrangement order was transposed symmetrically, and it was beneficial to improve the energy dissipation factor when the perforation rate decreased from the sound source side. Theoretical results were verified on a water-filled impedance tube using the two source-location methods. [ABSTRACT FROM AUTHOR]