The role of sodium silicate treated randomly distributed jute fiber core on the mechanical, thermal and fire behavior of novel sandwich structures

In this work lightweight and fire-resistant sandwich structures were fabricated and their mechanical, thermal, and fire behavior were investigated. The non-woven mat consisting of jute and polyester fibers at a ratio of 60:40 was used to manufacture Hybrid fiber reinforced Sodium silicate Composites (HSC) to be used as the core of the sandwich structure. The concentration of sodium silicate solution was varied (i.e., 80%, 90%, and 100%) to manufacture HSCs. The woven Jute fiber mat reinforced Epoxy Composites (JEC) were prepared using hand layup followed by light compression method to be used as the skins of the sandwich structures. The tensile and flexural test results revealed that HSC with 100% sodium silicate concentration showed increased strength and modulus. The thermal conductivity was not significantly affected by the sodium silicate solution concentration to prepare HSC and the thermal conductivity of the sandwiches are significantly lower than many existing jute-fiber based composites. However, the fire spread, and damage propagation during fire exposure test were significantly affected by the sodium silicate solution concentration. Sandwich with 100% sodium silicate solution concentration is found to have minimum damage due to fire exposure for 30 minutes. These findings provide a comprehensive understanding of the fabrication processes and design of the sandwich structures using HSC and JEC for applications where high strength, insulation, and fire resistance are required together.