Investigation On Properties Of Asphalt Mixture Containing Demolition Waste Obtained From Earthquake-damaged Buildings

Earthquake is a universal catastrophe which causes death of lives and produces large amounts of demolition waste. Meanwhile, China's construction of transportation infrastructure is developing in a rapid speed, causing the growing shortage of natural stone resources. In this paper, waste materials are used in asphalt pavement as recycled aggregate. Asphalt mixture was prepared using demolition waste obtained from earthquake-damaged buildings and various properties of asphalt mixture were investigated. A section of asphalt pavement containing demolition waste obtained from earthquake-damaged buildings was paved and the preparation and construction techniques were investigated.Waste materials were processed into recycled aggregate and used in asphalt mixture together with natural limestone aggregate. Because of the low strength and high absorption of recycled aggregate, a liquid silicone resin was used to pretreat the recycled aggregate. Various tests including physical properties test, surface morphology test of both untreated and pretreated recycled aggregate, moisture susceptibility test, permanent deformation test and three-point bending beam test of asphalt mixture were carried out. Experimental results indicated that the pretreatment of recycled aggregate by used liquid silicone resin improved the strength, absorption, adhesion with asphalt and surface morphology of recycled aggregate. The introduction of recycled aggregate had a negative effect on moisture resistance and low-temperature flexibility of asphalt mixture. However, the pretreatment of recycled aggregate by used liquid silicone resin can improve the properties mentioned above. Asphalt mixture containing recycled aggregate showed greater resistance to permanent deformation. The pretreatment of recycled aggregate by used liquid silicone resin tended to reduce the resistance of asphalt mixture to permanent deformation. However, asphalt mixture containing recycled aggregate is still superior in resistance to permanent deformation at high-temperature after pretreatment. Key techniques on preparation and construction in plant were investigated from the viewpoint of pretreatment of recycled aggregate, design of asphalt mixture containing demolition waste obtained from earthquake-damaged buildings and control of construction process. Results showed that the pretreatment of recycled aggregate is feasible and effective; the design of asphalt mixture is rational; and the production process is stable which ensures a smooth construction. The skeleton structure of paved asphalt mixture is homogeneous and dense; and the moisture resistance and permanent deformation resistance of asphalt mixture containing demolition waste obtained from earthquake-damaged buildings are superior to the ordinary asphalt mixture used in the same section.In conclusion, utilization of demolition waste obtained from earthquake-damaged buildings in asphalt mixture is technically feasible with the substitution of recycled aggregate by natural limestone aggregate and the pretreatment of coarse recycled aggregate by used liquid silicone resin.