The Performance Study Of SMA Modified By Silane Coupling Agent

With the rapid development of China’s national economy, more and more roaddue to the increase of traffic flow, and bad weather and engineering technical reasonsto crack, rutting and water damage and pavement diseases, common asphalt road hasbeen difficult to bear all the heavy traffic. Therefore, how to effectively prolong roadservice life has become one of the important research agenda. SMA pavement hasbecome one of the most popular high-grade asphalt pavement, because it has goodtemperature stability, excellent skid resistance, low noise, durable and othercharacteristics.In actual asphalt road construction, due to the limit by the raw materials, Granite,jadeite quartzite, sand, stone often use for rock of asphalt mixture aggregate. Thiskind of stone contained more silica, water absorption performance is strong, soadhesion between acidic stone and asphalt is poor. Under the effect of snow and rain,asphalt easy to fall from the stone surface, that can lead to the destruction of thepavement, so the adhesion between asphalt and aggregates has direct influence on theroad properties of asphalt mixture.The paper choose basalt fiber alternative wooden fiber, as a fiber stabilizer addedto the SMA. Although at present the wooden fiber is extensively applied to theSMA,the wooden fiber in asphalt mixture easy to cause a series of heat degeneratereaction, fiber ageing or degenerate easily, even down into carbon coke, the water,carbon dioxide and other substances, these substances will pollute asphalt in asphaltmixture, cause every performance of asphalt decline. The wooden fiber before is usedin SMA road in some country, but when they regenerate pavement, they can’t find anywooden fiber in asphalt mixture and find wooden fiber decomposition productspollute pitch and makethe performance of asphalt greatly reduced.Then vegetablefiber has certain water absorption performance, it absorbs moisture to forming a layerwater film, water film easy to cause the asphalt mixture water damage. But basalt fiber has good low temperature and high temperature stability,it can normal workin-269~900℃temperature, it has excellent mechanical properties and tensilestrength,the elastic modulus and elongation at all is bigger. So it can completelyreplace wooden fiber as a composite reinforced in many applications.Aim at the influence of adhesion between asphalt and aggregates on the SMAroad performance, this article use the silane coupling agent to modify aggregate andfiber surface. Silane coupling agent is a kind of organic silicon compounds whosemolecules has two groups of functional group,One is close inorganic group,whichreacts easily with the surface of inorganic chemical;The other is a close organicgroups, which can reacts with asphalt,so it can Improve the performance of thecomposite materials,such as physical properties and mechanical properties. the boiledexperimental results comparison,we found silane coupling agent can significantlyimprove the adhesion between asphalt and aggregate. At the same time, through therutting test, inundate Marshall test and low temperature trabecular bending test resultscomparison, silane coupling agent can significantly improve high temperature stability,the low temperature crack resistance and water stability properties.