Innovative Gypsum–Particle Composite Used as Building Structural Panels

Abstract

An innovative preparation method was invented that adds adhesive to gypsum–particle composites. The effects of varying the wood particle to gypsum ratio and melamine-urea-formaldehyde adhesive (MUF) content on mechanical properties and combustion performance were examined and discussed. Microscopic analyses revealed the mechanism of improvement in this innovative gypsum–particle composite (IGP). The ignition point of IGP was high and the heat and smoke release rate low, with the peak release time greatly delayed compared to structural wood-based composites. The mass retention of IGP was greatly increased and its charred appearance slight. The internal bonding strength (IBS), bending strength (modulus of rupture, MOR), and modulus of elasticity (MOE) of IGP with 9.0% MUF content were 3.4, 4.8, and 3.9-fold higher, compared to gypsum board, respectively. IGP with 7.6% MUF appeared to be suitable as load-bearing panels. MUF content positively affected IGP properties and a 7.6% MUF content and 3/10 wood particle to gypsum ratio were found to be optimal for IGP production. The IBS, MOR, and MOE reached 1.28, 16.10, and 6,861 MPa, such that these composites could be used as building materials. The lateral elastic stiffness and maximum load of IGP nail connections were 313.6 kN·m−1 and 1,386 N under parallel-to-grain load, respectively.