A new flame retardant and its effect on the asphalt mixture

Abstract

To alleviate the problem of decomposition products of organic flame retardants with toxic, inorganic flame retardants were used to prepare flame retardant modified asphalt (FRA), but the traditional inorganic flame retardants have a significant flame retardancy only with a high dosage, and too high dosage would bring serious adverse effects on the pavement performance of asphalt mixture. For this, to avoid the side effects of inorganic flame retardants, a compound flame retardant was developed by orthogonal experiment method to alleviate the problem of high dosage of inorganic flame retardants, and to have a relatively significant flame retardancy. The flame retardancy was studied by conventional performance test, separation test, rotational viscosity (RV) test, dynamic shear rheology (DSR) test, limiting oxygen index (LOI) test, thermogravimetry (TG) test, pavement performance test, and combustion test. The results show that with the addition of self-developed flame retardant (WZRJ-I), the PI of FRA was increased by 23.4∼40.4 % compared with virgin asphalt, the LOI was increased by 24.7∼46 %, the rutting factor was increased by 12.6∼27.9 %, the thermal decomposition parameters were significantly improved at all stages, the burning time was reduced by 39 s∼53 s, the mass loss was reduced by 11.9∼15.4 %, which indicated that the addition of WZRJ-I was conducive to improve the flame retardancy and high temperature performance. Finally, the prediction equation model of combustion performance index and burning time of asphalt mixture was established, and the effect of burning time on the residual pavement performance of asphalt mixture was quantitatively analyzed.