Research On Bone Glue/Rubber Composite Modified Asphalt And Its Mixture

Bone glue(BG)and crumb rubber(CR),as waste derivatives,have the advantages of low cost,green,and extensive sources.Rubber asphalt has good high and low temperature properties and fatigue resistance,but its storage stability has always been an urgent problem to be solved;Bone glue has excellent effect on improving the high temperature performance of asphalt,but weakens the low temperature performance of asphalt.If the two are compounded into pavement asphalt,it can not only form green recycling of waste resources,but also make up for the performance defects of single modification.In view of the above technical problems,this study proposed a green and sustainable waste utilization technology,namely,the development of BG/CR composite modified asphalt,which has provided a feasible scheme for the joint application of bone glue and rubber in pavement engineering.Firstly,a new type of bone glue aqueous solution was prepared to ensure the smooth fusion of bone glue and matrix asphalt.Then the preparation process of BG/CR composite modified asphalt was determined.A series of conventional tests and rheological tests,including penetration,softening point,phase separation,temperature sweep,multiple stress creep and recovery,were used to evaluate high-temperature properties.Bending beam rheological test and ductility test were carried out to assess the low-temperature characteristics of composite modified asphalt.Secondly,the short-term and long-term aging of composite modified asphalt were carried out by rotating film oven heating test and pressure aging test.The aging properties of BG/CR composite modified asphalt were systematically evaluated by taking the complex modulus,rutting factor,unrecoverable creep compliance after short-term aging and low-temperature creep stiffness after long-term aging as evaluation indexes.Besides,the performance grade of BG/CR composite modified asphalt grade has been completed.Moreover,the functional groups of the chemical components of BG/CR composite modified asphalt were identified by the Fourier transform infrared spectroscopy,and the microstructure of the composite modified asphalt was studied by fluorescence microscope and scanning electron microscope.Finally,the adhesion ability between aggregate and different asphalt was compared and analyzed by contact angle test.Finally,in order to reflect the consistency of micro modification mechanism and macro road performance of BG/CR composite modified asphalt,a series of studies on the performance of BG/CR composite modified mixture were carried out.The high-temperature stability,low-temperature crack resistance and water stability tests of the matrix asphalt,bone glue asphalt,rubber asphalt,and composite modified asphalt were compared and analyzed,and the performance superiority and engineering practicability of BG/CR composite modified asphalt mixture were comprehensively evaluated.To sum up,by comparing and analyzing a number of performance indexes of BG/CR composite modified asphalt and its mixture,the optimum content of modified material has been determined,and the performance superiority and engineering feasibility have been verified.A modified asphalt material with high performance,low cost and strong engineering applicability has been developed.