常温域沥青表面纳观构造及粘附特性研究

发布时间：2018-09-18 13:20

【摘要】：沥青混凝土路面松散、掉粒等早期损坏与沥青集料的粘附性能密切相关。沥青路面在服役过程中,温度变化对沥青集料的粘附性能必然产生了影响。至于影响如何,之前限于科学技术水平的不足,国内外学者大多从宏观角度对其展开研究。近几年,随着原子力显微镜(AFM)等纳米级探测技术的发展和进步,以及材料界多尺度观测的流行等,从纳观角度研究常温域对沥青表面构造及力学特性的影响成为可能。因而,本文以AFM为试验手段,对两种油源共四种沥青在常温域下的纳观构造及粘附性能展开了研究,辅以四组分在相同试验条件下的纳观构造及粘附性能,对沥青集料粘附机理进行探索性研究。首先选定安达50号、90号及韩国SK70号和SBS改性沥青四种沥青,用热铸法浇筑沥青试样,用溶解法浇筑四组分试样。对其在常温域下加热后试扫AFM形貌图和力曲线,结果表明,所选四种沥青在AFM下可测最高温度为65℃,四组分随组分不同可测最高温度也不同。当温度超过可测最高温度时,测试过程中会频繁出现跳针或Trace和Retrace两条线基本不能重合的现象,所测形貌及力曲线无意义。另外,试扫发现安达沥青含有蜂型结构,SK沥青则无明显蜂型结构,但也含有特殊构造均匀分布在沥青中。对含有蜂型结构的90号沥青的四组分进行AFM测试发现,一次加热并自然降至室温后的芳香分纳观形貌图中亦包含蜂型结构。其次对四种沥青和组分进行了变温测试,并利用QNM模式对其形貌和力曲线进行扫描。采用Nano Scope Analysis对不同温度下试样的纳观形貌进行了粗糙度参数统计,由粘附力分布图统计分析其粘附力变化趋势,对比沥青纳观形貌图和粘附力分布图发现二者之间具有较好的对应性,而组分则无此特性。应用Oliver-Pharr模型对沥青及其组分在常温域下的纳米硬度进行了分析。结果显示不同沥青或者组分其纳观构造及粘附特性随温度变化的趋势有较大差别。最后在常温域下对沥青进行了宏观剥离试验,结果显示各沥青随温度升高剥离力迅速降低,且剥离试样的破坏模式随温度升高由粘附破坏转变成了粘聚破坏。对比相应沥青纳观粘附力和表面粗糙度,发现二者与其宏观试验结果因破坏界面的差异而呈现不同的趋势变化。
[Abstract]:The early damage of asphalt concrete pavement is closely related to the adhesion of asphalt aggregate. During the service of asphalt pavement, the temperature change will inevitably affect the adhesion of asphalt aggregate. As for the influence, it is limited to the deficiency of science and technology level before, most scholars at home and abroad study it from the macro point of view. In recent years, with the development and progress of nano-scale detection technology such as atomic force microscope (AFM), and the popularity of multi-scale observation in the field of materials, it is possible to study the influence of atmospheric temperature region on the surface structure and mechanical properties of asphalt from the viewpoint of nano observation. Therefore, by means of AFM, the nano structure and adhesion properties of four kinds of bitumen from two oil sources in the normal temperature range were studied, and the conformability and adhesion of the four components under the same test conditions were also studied in this paper. The adhesion mechanism of asphalt aggregate was studied. First, four kinds of bitumen, Anda 50, 90, Korea SK70 and SBS modified bitumen, were selected. The hot casting method was used to cast the asphalt samples, and the dissolution method was used to cast the four component asphalt samples. The AFM topography and force curve of the asphalt were examined after heating at room temperature. The results showed that the highest measurable temperature of the four asphalts was 65 鈩，

本文编号：2248044