Experimental and theoretical study on flexural performance of lightweight sandwich panels using FRP connectors

Prefabricated concrete sandwich panels are crucial components in the construction of prefabricated buildings, providing essential functions such as load-bearing capacity, thermal insulation, and fire resistance. The development of sandwich panels is oriented toward achieving lightweight, high-strength structures with superior thermal insulation properties. This study introduces two types of innovative sandwich panels using TRM rib with FRP composite bolts and FRP pultruded profiles as connectors, respectively. Comprehensive experiments were conducted to evaluate their construction methods and flexural performance with different thicknesses (i.e., 100 mm and 150 mm). The test results indicate that the proposed sandwich panels can be fabricated in large dimensions of 4 m × 3 m and can withstand substantial equivalent wind loads. The different sandwich panels exhibited distinct failure modes and various composite actions of 8.04%, 28.36%, 49.56%, and 85.67%. Subsequently, this work presents a theoretical analysis model for predicting the initial stiffness, which has achieved favorable accuracy. Comparative analysis with other studies indicates that the sandwich panels investigated are classified as lightweight, high-strength and thin sandwich panels, which demonstrate significant potential for practical applications.