以消散能法評估瀝青混凝土之疲勞特性

Evaluation of Hot Mix Asphalt Fatigue Using Dissipated Energy Method

曾劭逵(Shao-Kuei Zeng)

指導教授 ： 劉明仁

淡江大學/工學院/土木工程學系碩士班/碩士(2022年)

https://doi.org/10.6846/TKU.2022.00379

摘要

疲勞破壞為路面常見破壞模式之一，路面在車輛載荷反覆作用下，瀝青混凝土材料性能逐漸衰減直至裂開，此衰減過程即為疲勞。本研究依據試驗計畫，採用馬歇爾配合設計方法，製作密集配瀝青混凝土之馬歇爾試體，再遵照歐盟EN12697-24:2012 Annex E 規範與條件（變化加載、溫度與頻率）進行間接張力式之瀝青混凝土疲勞試驗。疲勞試驗數據結果再以消散能法與傳統法進行瀝青混凝土試體之疲勞分析與評估。依據本研究疲勞試驗結果之數據分析，獲得主要結論歸納如下：
1. 依據本研究間接張力疲勞試驗於能量比（ER）分析法與消散能比（DER）分析法兩者之結果，相同溫度與應力水準下，加載之頻率愈高，其起始消散能（W0）愈低，疲勞壽命愈長；相同溫度與加載頻率下，加載之應力水準愈高，其起始消散能（W0）愈高，疲勞壽命愈短；相同應力水準與加載頻率下，試驗溫度愈高，其起始消散能（W0）愈高，疲勞壽命愈短。
2. 依據本研究間接張力疲勞試驗於能量比（ER）分析法與消散能比（DER）分析法兩者之結果，各個溫度與頻率之起始消散能（W0）與疲勞壽命（Nf）散佈圖與迴歸分析結果，顯示瀝青混凝土之起始消散能愈高，其疲勞壽命愈短。
3. 本研究間接張力疲勞試驗之消散能變化比（RDEC）分析結果並未顯示與文獻相同之趨勢，推斷其原因可能來自疲勞試驗儀設備之訊號數據擷取受到不明原因干擾，試驗試體之材料性質（空隙率、勁度模數）不穩定，或試體數目過少所致。
4. 本研究間接張力疲勞試驗之現象學（傳統疲勞理論）分析結果，顯示瀝青混凝土試體於相同溫度與應力水準下，加載之頻率愈高，其疲勞壽命愈短；相同溫度與加載頻率下，加載之應力水準愈高，其疲勞壽命愈短；相同應力水準與加載頻率下，試驗溫度愈高，其疲勞壽命愈短。
5. 依據本研究間接張力疲勞試驗之現象學（傳統疲勞理論）分析結果，由各個溫度與頻率之應力水準與疲勞壽命（Nf）散佈圖與其迴歸分析結果顯示，相同溫度與加載頻率之條件下，瀝青混凝土之應力水準愈高，其疲勞壽命愈短。

關鍵字

瀝青混凝土 ； 間接張力疲勞試驗 ； 消散能

並列摘要

Fatigue failure is one of the common failure modes of pavement. Under the repeated action of vehicle load, the performance of asphalt concrete material gradually decays until it cracks. This decay process is fatigue. In this study, according to the test plan, the Marshall combination design method was used to make Marshall specimens of densely mixed asphalt concrete, and then the indirect tension type asphalt was carried out in accordance with the EU EN12697-24:2012 Annex E specification and conditions (variable loading, temperature and frequency). Concrete fatigue test. The fatigue test data results are then used to analyze and evaluate the fatigue of the asphalt concrete specimen by the dissipated energy method and the traditional method. Based on the data analysis of the fatigue test results in this study, the main conclusions are summarized as follows:
1. According to the results of both the energy ratio (ER) analysis method and the dissipation energy ratio (DER) analysis method of the indirect tension fatigue test in this study, under the same temperature and stress level, the higher the loading frequency, the higher the initial dissipation energy ( The lower W0), the longer the fatigue life; under the same temperature and loading frequency, the higher the loading stress level, the higher the initial dissipation energy (W0), the shorter the fatigue life; under the same stress level and loading frequency, the test temperature The higher the value, the higher the initial dissipation energy (W0) and the shorter the fatigue life.
2. According to the results of both the energy ratio (ER) analysis method and the dissipated energy ratio (DER) analysis method of the indirect tension fatigue test in this study, the initial dissipation energy (W0) and fatigue life (Nf) distribution of each temperature and frequency Figure and regression analysis results show that the higher the initial dissipated energy of asphalt concrete, the shorter its fatigue life.
3. The analysis results of the Ratio of Dissipated Energy Change (RDEC) of the indirect tension fatigue test in this study did not show the same trend as the literature. It is inferred that the reason may be that the signal data acquisition of the fatigue tester equipment is disturbed by unknown reasons. Material properties (porosity, stiffness modulus) are unstable, or the number of specimens is too small.
4. The phenomenological (traditional fatigue theory) analysis results of the indirect tension fatigue test in this study show that under the same temperature and stress level, the higher the loading frequency of the asphalt concrete specimen, the shorter the fatigue life; under the same temperature and loading frequency , the higher the loading stress level, the shorter the fatigue life; under the same stress level and loading frequency, the higher the test temperature, the shorter the fatigue life.
5. According to the phenomenological (traditional fatigue theory) analysis results of the indirect tension fatigue test in this study, the stress level and fatigue life (Nf) scatter diagram of each temperature and frequency and the regression analysis results show that under the conditions of the same temperature and loading frequency, , The higher the stress level of asphalt concrete, the shorter its fatigue life.

並列關鍵字

asphalt concrete ； indirect tension fatigue test ； dissipated energy

參考文獻

1. 楊富程，「AC-20 瀝青混合鋪面試驗路段之成效評估」，中央大學 土木研究所碩士論文。2006年

2. DIN EN 12697-24: 2012, Bituminous mixtures - Test methods for hot mix asphalt - Part 24: Resistance to fatigue (2012).

3. 中華民國交通部公路總局，「施工方程式中書　02741瀝青混凝土之一般要求」，2012 年 10 月版（2020年06月修訂）。

4. 張景祺，「溫拌瀝青混凝土之間接張力疲勞試驗初探」，淡江大學土木工程學系碩士班碩士論文，2017年

5. Maggiore, Cinzia, “A comparison of different test and analysis methods for asphalt fatigue.” PhD Thesis at the University of Nottingham. Nottingham Transportation Engineering Centre (NTEC). Nottingham, UK. 2014.