Investigation of asphalt mixture containing demolition waste obtained from earthquake-damaged buildings

Some properties of asphalt mixture containing demolition waste obtained from Wenchuan earthquake-damaged buildings were investigated in this paper. 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. Based on an extensive test program presented in this paper, it can be concluded that demolition waste obtained from Wenchuan earthquake-damaged buildings can be used as recycled aggregate to prepare asphalt mixture with satisfactory properties.