再生骨料表面改性及在沥青混凝土中的应用研究

为提高再生骨料品质,并研究其在沥青混凝土中的应用效果,采用有机硅树脂溶液对再生骨料表面进行改性,研究改性技术及再生骨料掺量对沥青混凝土路用性能的影响。通过车辙试验、小梁低温弯曲试验和水稳定性试验对混凝土高温、低温及水稳定性能进行评价。结果表明,未改性处理的再生骨料沥青混凝土的高温、低温及水稳定性能均弱于天然骨料沥青混凝土,且随着再生骨料掺量的增加,路用性能进一步变差。相比再生骨料,在相同掺量下,有机改性再生骨料沥青混凝土的路用性能均有所提高。说明采用有机硅树脂溶液改性再生骨料表面可有效改善沥青混凝土的路用性能。综合高温稳定性、低温抗裂性能和水稳定性随再生骨料掺量的变化情况,建议将再生骨料的掺量控制在60%以内(取代天然粗集料的比例),而改性再生骨料则可用于完全替代天然粗集料。

In order to improve the properties of recycled aggregate and reveal its application effect in asphalt concrete,the surface of recycled aggregate was modified by silicone resin solution,and the influence of modification technology and the dosage of recycled aggregate on the pavement performance of asphalt concrete was investigated.The high-temperature stability,low-temperature crack resistance and water stability of asphalt concrete were evaluated by rutting test,low-temperature beam bending test and water stability test.The results showed that the high-temperature stability,low-temperature crack resistance and water stability of unmodified recycled aggregate based asphalt concrete were weaker than natural aggregate based asphalt concrete,and with the increase of recycled aggregate content,the main pavement performance further deteriorated.Compared with unmodified recycled aggregate,the main pavement performance of organically modified recycled aggregate based asphalt concrete was improved under the same dosage.It showed that modifying recycled aggregate with silicone resin solution can effectively improve the pavement performance of asphalt concrete.Considering the changes of high-temperature stability,low-temperature crack resistance and water stability with the increase of recycled aggregate content,it was recommended to keep the content of unmodified recycled aggregate below 60%(replacing the proportion of natural coarse aggregate),while the modified recycled aggregate can be used to completely replace natural coarse aggregate.