Investigation on the Performance of Fire and Smoke Suppressing Asphalt Materials for Tunnels

The volatilization of asphalt fumes not only affects the health of construction workers, but also damages the environment. It even affects the construction quality of asphalt pavement in tunnels. This article focuses on solving the emission of asphalt fumes to better protect human health and the environment, while satisfying the use of asphalt pavement. A flame retardant and smoke suppressant (compound) with Mg(OH)2 as the main component was developed, and flame retardant asphalt mixture and asphalt mastics were prepared to evaluate the flame retardant and smoke suppressant properties and performance effects. Firstly, its low- and high-temperature performances were investigated with BBR and DSR, respectively. Then, the indoor combustion test and the cone calorimeter test were used to evaluate the fire retardant smoke suppression effect of the asphalt mastic. Thirdly, the flame retardant effect of asphalt mastic mixed with the compound was further analyzed by the TG test and SEM. The pyrolysis temperature, mass loss, and microscopic state of the asphalt surface were used to verify and explain the flame retardant reaction effect and process of the compound. Finally, the asphalt mixture performance was evaluated, as well as the flame retardant smoke suppression effect by asphalt mixture combustion tests. The results showed that the flame retardant smoke suppression time of the flame retardant asphalt mixture was reduced by 66%, and the smoke emission area was reduced by 20%. The flame retardant smoke suppression effect of the asphalt mixture was improved by 44%. It is proven that this kind of fire retardant and smoke suppressing asphalt mastic and mixture met performance needs in use, and the fire retardant and smoke suppressing effect was obvious. This solution addresses the issue of asphalt smoke generated during the construction of asphalt pavement, providing better support for the construction of asphalt pavement in tunnels.