The Preparation And Flame Retardancy Of Organo-montmorillonite/Hydroxid Modified Asphalt

With the rapid development of transportation and constant improvement of road grade, the scale andamount of the highway tunnel enlarge and increase. The inner space of the tunnel is strait and enclosedspace, once vehicle be in trouble and bring fire, the combustible liquid may overspread fire behaviour. Inthis moment, a lot of smoke and toxic gases are released due to the combustion of asphalt fuel, whichserious threat the life of staffs. In addition, the hot mix asphalt is widely used in asphalt pavement in thetunnel now, but it releases a lot of smoke and toxic gases, which will deteriorate in the quality of thehighway construction environment. So it needs to exploit a kind of environment-protecting, energy-savingand flame-retarded asphalt pavement material.The research is based on Key Program of Natural Science Foundation for Basic Research Plan ofShaanxi Province “The basic research of environmentally friendly asphalt pavement in tunnel”. Contraposethe above problems, it needs to exploit a kind of zeto halogen, effective, low-smoke, low-toxic andmultifunction flame retardant. Through extensive research and experiment tests, Organ-montmorillonite(OMMT)/aluminium trihydroxide (ATH) combination has low dosage and effective flame retardant, andhas little influence on the pavement performance of matrix asphalt. The results of research are as follows.The combustion process of matrix asphalt is studied in the atmosphere of nitrogen withTG-DSC-FTIR. The results show that the combustion process of matrix asphalt is divided into three stages.Furthermore, the main gas products of asphalt binder combustion are CO2, CO, H2O, SO2, methanol,formic acids, naphthenic acids, aromatic compounds, alkane, phenol, etc. In the2nd combustion stage, themass loss rate of asphalt reaches a maximum,57.4%. OMMT modified asphalts are prepared by usingmelting intercalation technology, and whose dispersing states of OMMT layers in the asphalt arecharacterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The results showthat OMMT layers double and OMMT distributes homogeneously. Besides, the flame resistance effect ofOMMT, ATH, magnesium hydroxide (MH), OMMT/ATH and OMMT/MH are assessed by LimitedOxygen Index (LOI) and Synergetic Efficiency (SE), the results show that OMMT/ATH combination caneffectively improve the flame resistance effect on condition that the pavement performance ofOMMT/ATH modified asphalt remain unchanged or enhance. The LOI and SE of1%OMMT+3%ATHmodified asphalt are27.1%and6.3%, respectively. Furthermore, the1%OMMT+3%ATH combination can improve high temperature stability, but the plastic temperature range and low temperature performancedegrade slightly. After the integrated consideration of high-temperature properties, temperature sensitivity,low-temperature and flame resistance, the optimum combination is1%OMMT+3%ATH.This paper first adopts OMMT and ATH combination as flame resistance, which has low dosage andeffective flame retardant. Meanwhile, these results offer reference and a new method for further studyingon pavement flame resistance.