铁尾矿沥青混合料基本性能及老化耐久性研究

Research on Basic Performance and Aging Durability of Iron Tailings Asphalt Mixture

为了避免过度使用天然砂石材料做为沥青混合料的骨料以及符合绿色发展的战略方针,采用固体废弃物铁尾矿来代替砂石材料来制备一种新型的铁尾矿沥青混合料。采用质谱仪对所选用铁尾矿进行化学成分分析,并对不同铁尾矿掺量作用下沥青混合料的针入度、锥入度、软化点、延度、粘度以及老化耐久性等方面进行了研究。研究结果表明:铁尾矿沥青混合料的较佳制备温度选定为180℃;综合经济效益和有效性确定铁尾矿的较佳掺量为30%;相对老化后的铁尾矿沥青材料而言,在同一铁尾矿掺量作用下两种不同沥青混合料老化前的针入度和延度均出现了降低的趋势,但是在同一铁尾矿掺量作用下两种不同沥青混合料老化前的软化点却出现了增大的趋势。综合分析得到:温度为180℃以及铁尾矿掺量为30%制备的沥青混合料可以满足公路的路用要求。所有沥青试样的光谱变化规律基本一致,说明了掺入铁尾矿改性沥青的结构与未掺入铁尾矿沥青的结构基本一致;但是随着铁尾矿掺量的增大,沥青的FT-IR光谱在同一波数作用下却呈现出不断减小的变化趋势,说明了铁尾矿可以有效改善沥青的物理性能。

In order to avoid excessive use of natural sand and gravel materials as aggregates of asphalt mixtures and to comply with the strategic policy of green development,solid waste iron tailings are used to replace sand and gravel materials to prepare a new type of iron tailings asphalt mixture.A mass spectrometer was used to analyze the chemical composition of the selected iron tailings.The penetration,penetration,softening point,ductility,viscosity and aging durability of asphalt mixture under different iron tailings content are studied.The research results show that the optimal preparation temperature of iron tailings asphalt mixture is selected as 180℃.Comprehensive analysis of economic benefits and effectiveness can determine the optimal content of iron tailings is 30%.Compared with the aged iron tailings asphalt material,the penetration and ductility of the two different asphalt mixtures before aging have a tendency to decrease under the same iron tailing content.However,under the effect of the same iron tailings content,the softening point of the two different asphalt mixtures before aging has a tendency to increase.Comprehensive analysis can be obtained:the asphalt mixture prepared with a temperature of 180°C and an iron tailing content of 30%can meet the road requirements of highways.The spectrum change law of all asphalt samples is basically the same.It shows that the structure of modified asphalt mixed with iron tailings is basically the same as that without iron tailings asphalt.However,with the increase of the iron tailings content,the FT-IR spectrum of the asphalt shows a decreasing trend under the same wave number.It shows that iron tailings can effectively improve the physical properties of asphalt.