【摘要】：瀝青混凝土路面松散、掉粒等早期損壞與瀝青集料的粘附性能密切相關。瀝青路面在服役過程中,溫度變化對瀝青集料的粘附性能必然產(chǎn)生了影響。至于影響如何,之前限于科學技術水平的不足,國內(nèi)外學者大多從宏觀角度對其展開研究。近幾年,隨著原子力顯微鏡(AFM)等納米級探測技術的發(fā)展和進步,以及材料界多尺度觀測的流行等,從納觀角度研究常溫域?qū)r青表面構(gòu)造及力學特性的影響成為可能。因而,本文以AFM為試驗手段,對兩種油源共四種瀝青在常溫域下的納觀構(gòu)造及粘附性能展開了研究,輔以四組分在相同試驗條件下的納觀構(gòu)造及粘附性能,對瀝青集料粘附機理進行探索性研究。首先選定安達50號、90號及韓國SK70號和SBS改性瀝青四種瀝青,用熱鑄法澆筑瀝青試樣,用溶解法澆筑四組分試樣。對其在常溫域下加熱后試掃AFM形貌圖和力曲線,結(jié)果表明,所選四種瀝青在AFM下可測最高溫度為65℃,四組分隨組分不同可測最高溫度也不同。當溫度超過可測最高溫度時,測試過程中會頻繁出現(xiàn)跳針或Trace和Retrace兩條線基本不能重合的現(xiàn)象,所測形貌及力曲線無意義。另外,試掃發(fā)現(xiàn)安達瀝青含有蜂型結(jié)構(gòu),SK瀝青則無明顯蜂型結(jié)構(gòu),但也含有特殊構(gòu)造均勻分布在瀝青中。對含有蜂型結(jié)構(gòu)的90號瀝青的四組分進行AFM測試發(fā)現(xiàn),一次加熱并自然降至室溫后的芳香分納觀形貌圖中亦包含蜂型結(jié)構(gòu)。其次對四種瀝青和組分進行了變溫測試,并利用QNM模式對其形貌和力曲線進行掃描。采用Nano Scope Analysis對不同溫度下試樣的納觀形貌進行了粗糙度參數(shù)統(tǒng)計,由粘附力分布圖統(tǒng)計分析其粘附力變化趨勢,對比瀝青納觀形貌圖和粘附力分布圖發(fā)現(xiàn)二者之間具有較好的對應性,而組分則無此特性。應用Oliver-Pharr模型對瀝青及其組分在常溫域下的納米硬度進行了分析。結(jié)果顯示不同瀝青或者組分其納觀構(gòu)造及粘附特性隨溫度變化的趨勢有較大差別。最后在常溫域下對瀝青進行了宏觀剝離試驗,結(jié)果顯示各瀝青隨溫度升高剝離力迅速降低,且剝離試樣的破壞模式隨溫度升高由粘附破壞轉(zhuǎn)變成了粘聚破壞。對比相應瀝青納觀粘附力和表面粗糙度,發(fā)現(xiàn)二者與其宏觀試驗結(jié)果因破壞界面的差異而呈現(xiàn)不同的趨勢變化。
[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，

本文編號：2248044