Experimental study on fire resistance improvement of wheat straw composite insulation materials for buildings

Abstract

The huge amount of agricultural waste in China has provided abundant raw materials for preparing building insulation materials. However, the flame retardancy of biomass insulation materials should be improved before being applied in buildings. In this work, effective techniques of carbonizing the biomass partially and adopting fireproof inorganic cementing materials were proposed to enhance the flame retardancy of the wheat straw insulation materials. Through different degrees of carbonization , the ignition point of raw biomass increased with the highest value being 258 °C. The fire performance test of flame spraying on the composite insulation materials showed that the local oxidation reaction of wheat straw was greatly reduced with the decrease of its solid residual rate. Besides, there was no smoke produced during the combustion process, and the oxidation reaction of biomass in the insulation materials was immediately extinguished when the flame was eliminated. Furthermore, the carbonized wheat straw insulation materials can always maintain structural integrity under flame spraying. The solutions proposed in this study can contribute to the excellent comprehensive properties of the biomass insulation materials, thus achieving the targets of protecting the safety of buildings and saving energy. • Agricultural waste is applied for preparing eco-friendly insulation materials. • Fire resistance of insulation materials is improved by carbonizing the biomass. • The fireproof geopolymer is adopted as the inorganic cementing material. • Biomass insulation materials can keep structural integrity under flame spraying.