布敦岩沥青复合改性SMA-13混合料设计及性能

Mixture design and pavement performance for BRA compound modified asphalt mixture SMA-13

为了提高SMA路面的高温抗变形能力,以布敦岩沥青（BRA）作为改性剂,对5种BRA掺量的BRA与SBS改性沥青复合改性沥青玛蹄脂碎石混合料SMA-13（简记为BSSMA-13）的配合比设计和路用性能进行了试验研究。根据BRA中纯天然沥青和矿物质含量及沥青混合料材料组成,提出了BRA改性沥青混合料配合比的计算方法,为其配合比设计提供了分析依据。研究结果表明：BRA可替代部分SBS改性沥青、细集料和矿粉,但不应采用BRA中纯天然沥青等量替代SBS改性沥青;BSSMA-13的总最佳油石比随着BRA掺量的增加而略有增加,在BRA掺量2%-5%范围内,提高0.1%-0.3%。路用性能检验表明：BRA的掺入可有效提高BSSMA-13的高温稳定性、水稳定性、抗弯拉强度及粘结性能,且具有良好的抗渗性能和抗滑性能,但对低温抗变形能力有一定影响。据此,确定BRA的适宜掺量为3%-4%。因此,BRA是一种性能优良的改性剂,经过改性的SMA-13适合于南方多雨地区大交通道路的桥面、隧道、长大纵坡及弯道等特殊路段的沥青路面。

In order to improve the high-temperature anti-deformation capacity of SMA pavement,the Buton rock asphalt （BRA）is used as the modifier to conduct the experi-mental research on the mixture design and pavement performance of compound modified stone mastic asphalt mixture SMA-13 of BRA and SBS modified asphalt （abbrevd BSS-MA-13）with five kinds of BRA mixing amount.According to the contents of pure nat-ural asphalt and mineral in the BRA as well as the material composition of asphalt mix-ture,the calculation method of mixture ratio of BRA modified asphalt mixture is put forward to provide an analysis basis for its mixture design.The mixture design results show that the BRA can be replaced by a part of SBS modified asphalt,fine aggregate and mineral powder,but the pure natural asphalt in BRA should not be applied for e-quivalent replacement of SBS modified asphalt.The total optimum oil-stone ratio of BSSMA-13 increases slightly with the increase of BRA mixing amount,and it increases about 0.1%-0.3% in the range of BRA mixing amount 2%-5%.The pavement per-formance tests show that the incorporation of BRA can effectively improve the high-temperature stability,water stability,flexural tensile strength and bond behavior of BSSMA-13 with the favorable performances of anti-permeability and skid resistance, but it has a certain influence on the low-temperature anti-deformation capacity.Hereby, the suitable mixing amount of BRA is obtained as 3%-4%.Therefore,BRA is a kind of modifier with excellent performance,and its modified SMA-13 is suitable for the as-phalt pavement of heavy traffic road in the special road sections including bridge deck, tunnel,large longitudinal slope and bend,etc.,in southern China＇s rainy region.