Structural behavior and vibration characteristics of geopolymer composite lightweight sandwich panels for prefabricated buildings

Abstract

In this study, two new types of geopolymer composite lightweight sandwich panels are developed for prefabricated buildings. The first one has Fiber-reinforced Geopolymer (FRG) composite skin layers and polyurethane (PUR) foam core, and the second one is based on the first panel but strengthened with Basalt fiber reinforced polymer sheet (BFRP). Experimental studies are conducted to investigate the structural behavior and vibration characteristics of these panels. The failure mechanisms and capacity of the developed lightweight sandwich panels under flexural and compressive loads are studied by experimental quasi-static tests. Experimental results from flexural and compressive loading tests match well those from analytical calculations. The experimental studies show that the lightweight sandwich panel has a competitive capacity for prefabricated buildings. The vibration characteristics of the developed lightweight sandwich panels are obtained by hammer impact vibration tests. The finite element models are developed to predict the vibration characteristics of the tested sandwich panels. The obtained natural frequencies and mode shapes from numerical analysis and experimental tests show that the developed finite element models can be used to predict the vibration characteristics of geopolymer composite lightweight sandwich panels accurately. The addition of BFRP sheet does not significantly change the vibration characteristics of the panels, but changes the failure mode of the developed sandwich panel from skin tension failure to PUR foam core shear failure.