Preparation And Properties Of SBS/MAH Modified Asphalt Crack Filling Materials

Crack is a key disease of asphalt pavement. Water on the surface of asphalt pavement may infiltrate into primary roads through the cracks, which greatly weakens the strength and stability of the primary roads, will cause the asphalt pavement suffer more severe damage. At present, polymer modified asphalt and polymer modified asphalt emulsion are widely used as the crack filling material (CFM). Whereas, most of the crack filling materials, which are in low flexibility a poor, take on low adhesive strength with the cracks. The materials aren't fit to shrinkage in low temperature, which makes a contribution to destroy of CFM, and cracks are formed again.In this thesis, SBS modified asphalt was modified by maleic anhydride (MAH) of different amount. SBS/MAH modified asphalt and SBS/MAH modified asphalt emulsion were prepared. Effect of the MAH on properties of SBS/MAH modified asphalt crack and SBS/MAH modified asphalt emulsion were investigated. The microstructure of SBS/MAH modified asphalt was characterized by fluorescent microscope.Physical properties testing of SBS/MAH modified asphalt indicated that the softening point, ductility at 5°C, recovery rate of elastic at 25°C and penetration index were enhanced by addition of MAH. The high-temperature storage stability was also improved by addition of MAH. Mechanical properties testing of SBS/MAH modified asphalt showed that the adhesive strength was greatly enhanced by addition of MAH, when the content of MAH was 0.4%, the adhesive strength was 1.35MPa, the increment rate can be up to 87.5%. At the same time, the tensile strength, elongation at break and flexibility at low temperature were improved by MAH.Study of SBS/MAH modified asphalt emulsion revealed the softening point, tensile strength, elongation at break and low temperature were improved by MAH. The adhesive strength significantly enhance by addition of MAH.Thermal-oxidative aging experiment showed aging of SBS/MAH modified asphalt crack filling material would occur on the condition of thermal and oxygen, in the person of increment of softening point, decrement of ductility, and decrement of adhesive. Thermal-oxidative aging experiment showed that the thermal-oxidative aging was restrained by addition of maleic anhydride, especially for the content of maleic anhydride was more than 0.3%. It can be attributed to that number of C=C was reduced by chemical modification. Degradation of SBS on the condition of thermal-oxidative aging was restrained. Thus, SBS/MAH modified asphalt crack filling material is steadier than SBS modified asphalt crack filling material. Influence of thermal-oxidative on SBS/MAH modified asphalt crack filling material is less than that of SBS modified asphalt crack filling material.