Study on the Preparation Road Performance of New Inorganic Fire-Retardant-Modified Asphalt

Abstract

To develop a purely inorganic fire-retardant-modified asphalt, we selected highly fire-retardant materials that have low-carbon content, non-polluting properties, and are inexpensive as fire retarder of asphalt. The optimal preparation technique for inorganic fire-retardant-modified asphalt is determined on the basis of three indexes of modified asphalts. First, limiting oxygen index and smoke density tests are conducted to investigate the influencing regularity of the dosage and type of inorganic fire retarder on fire and smoke retardant properties of inorganic fire-retardant-modified asphalt. Second, the TG test is used to explore the fire-retardant mechanism of inorganic fire-retardant-modified asphalt. Third, by testing the viscosity, anti-aging property, and adhesion of the inorganic fire-retardant-modified asphalt, the influencing regularity of inorganic fire-retardant dosage on the road performance of the modified asphalt is studied. Finally, the economic benefits of the inorganic fire-retardant-modified asphalt are analyzed. Results showed the following: (1) the inorganic fire retarder has good fire and smoke retardant properties and can meet the requirements of the corresponding national specifications; (2) the fire-retardant property of the inorganic fire-retardant-modified asphalt can be increased significantly by increasing the dosage of the fire retarder, and the smoke retarder can improve the fire-retardant property with its functions (these properties overcome the contradictory shortcomings between fire and smoke retardant properties); (3) the effect of the fire retardant mainly depends on the decomposition and release of water from the inorganic fire retarders, and the absorption effect of the layered metal oxide; (4) with the increasing dosage of the inorganic fire retarder, the degree of penetration and ductility of the inorganic fire-retardant-modified asphalt decreases, the softening point and viscosity increase, and the penetration ratio and viscosity become larger; (5) the addition of the inorganic fire retarder does not affect the adhesion of SBS-modified asphalt. The inorganic fire-retarder has excellent economic benefits and is suitable for promotion and application in fire-retardant asphalt mixtures for pavements.