The Research On The Mechanism Of DBDPE Composite Flame Retardant Asphalt

With the development of the tunnel asphalt pavement,due to the flammability of asphalt,the flame retardant technology of tunnel asphalt pavement has been widely concerned.On account of the present research situation of flame retardant asphalt trend to flame resistant properties and performance effect of asphalt,it is necessary to study the mechanism of the flame retardant effect of asphalt.Due to wet environment of tunnel pavement,the higher requirement of resistance to moisture of asphalt pavement has been put forward.Therefore,it is necessary to research the effect of flame retardant on the properties of asphalt,and especially on the adhesion properties between asphalt and aggregate.In this paper,the object of study is a composite flame retardant based on decabrominated dipheny ethane?DBDPE?.Firstly,thermal analysis,calcination analysis and infrared spectroscopic analysis have been used to research the pyrolysis regularity of DBDPE,antimonous oxide?Sb₂O₃?and aluminum hydroxide?ATH?,as well as DBDPE-Sb₂O₃composite flame retardant and composite flame retardant of three flame retardant.Then thermal analysis is used to flame retardant asphalt.Comparative analysis of thermal analysis between flame retardant asphalt and flame retardant,conclusions can be made as follows:?1?DBDPE start decomposition at 350?,resulting in HBr gas,can effectively inhibit the chain reaction of asphalt pyrolysis,at the same time the product at 400?can also has condensed phase flame retardancy effect.?2?Sb₂O₃ mainly due to the heat absorption of sublimation,it has a certain endothermic flame retardant effect.But for economic consideration,Sb₂O₃ generally not used for individual use.?3?On the one hand,ATH can be decomposed to absorb heat in a wide range of temperature.On the other hand,it can generate water vaporis which also has a certain flame retardant effect,and the product Al₂O₃ with condensed phase flame retardant effect.?4?DBDPE-Sb₂O₃ flame retardant is mainly gas phase flame retarding:the generated gas can consume free radical of asphalt pyrolysis reacton,on the other hand the high density gas product can also isolation air.?5?Due to ATH formation of Al₂O_3,the composite flame retardant has better performance of carbon formation,which indicates that ATH has a good synergistic effect on flame retardant of DBDPE-Sb₂O₃ flame retardant.?6?Two kinds of warm-mixd agent Sasobit and 3G inhibit the carbon reaction of composite flame retardant,it is recommended to consider the influence of warm-mixd agent on the flame retardant effect.The contact angle measuring instrument has benn developed,and testing methods has been made.The surface energy of the liquid contact angle sensitivity analysis has been made.The surface energy parameter of flame retardant and flame retardant asphalt have been tested.Then comparation analysis with mineral powder and asphalt mortar have been made.Based on the summary of asphalt-aggregate adhesion model,DSR test and quantitative evaluation test method of asphalt-aggregate resistance to moisture,the correlation analysis of flame retardant asphalt adhesion and adhesion performance was carried out.Results show that:?1?The surface energy on the test liquid contact angle sensitivity:glycerol>formamide>distilled water.?2?The surface energy and phase angle?of asphalt has a certain correlation.?3?Adhesion model three has good applicability to the proposed test method.The calculation shows that the flame retardant asphalt has better adhesion properties with aggregate than two kinds of asphalt mortar.?6?The two calculation method can be better applied to the test in this paper.