| The recycled aggregate contains cement mortar,and cracks are generated during the crushing process,resulting in its characteristics of large porosity,low strength,high water absorption,etc.When it was used to formulate asphalt concrete,the road performance will have a certain degree of defects.In this paper,the aggregate were reinforced with silicone resin and modified with nano-calcium carbonate,then the road performance of asphalt concrete composed of double-modified aggregate was studied.Firstly,5~10mm and 10~20mm recycled aggregates were reinforced with 5.5%and 3% silicone resin respectively,their apparent density,relative volume density,water absorption,crushing value,Los Angeles wear value and asphalt adhesion performance were then tested and compared with natural aggregates and original recycled aggregates.The test results show that the water absorption of the recycled aggregate after treatment with the silicone resin resin is greatly reduced,and the crush value and Los Angeles wear value are reduced to some extent,which indicates that the strength of the recycled aggregate is improved by the silicone resin treatment.As for asphalt adhesion,it was improved after being treated.When it comes to the influence of nano-calcium carbonate,the comparison of basic parameters between unmodified bitumen and bitumen added with nano-calcium carbonate shows that the penetration of modified nano-calcium carbonate has a small increase,and the change range of softening point is not large,and the ductility has a certain degree of reduction.The blending ratio of recycled aggregate in asphalt concrete was divided into 0,30%,70%,and 100%,the results showed that: first,with the increase of recycled aggregate dosage,the optimal amount of asphalt was increased.second,the optimum amount of asphalt is reduced after being strengthened with the silicone.After determining the optimum amount of bitumen,asphalt concrete was mixed to study its road performance.The results show:1.the dynamic stability of asphalt concrete increases with the increase of recycled aggregate;2.Under the same amount ofrecycled aggregates,the dynamic stability of asphalt concrete treated with nano-CaCO3 and silicone resin is greater than that of silicone resin alone.3.The dynamic stability of Asphalt concrete increases with the increase of recycled aggregates;4.With the increase of recycled aggregates,the residual stability gradually decreases.With the same amount of recycled aggregate,the residual stability of organosilicon resin after treatment is better than the effect of the treatment of nano-calcium carbonate and silicone resin.besides,the recycled aggregate was untreated was related to the worst.5.for the Marshall stability and the water-soaked Marshall stability,the double-treatment relate to the highest,and the asphalt resin treated with the silicone resin was the second,The untreated recycled aggregate is the worst in asphalt concrete. |
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