论文部分内容阅读
沥青混合料的疲劳开裂是最为常见的路面病害之一。在进行混合料的试验室配合比设计时,寻求最为合适的骨料来保证混合料良好的路用性能,以抵抗路面疲劳开裂,显得尤为重要。沥青混合料的抗拉和抗剪强度主要由其内部粘结力来提供,而沥青的种类以及沥青砂浆的强度都会对粘结力产生影响。沥青混合料的抗压强度和承载能力主要由其矿料骨架来提供,因此骨料的级配曲线以及骨料的形状影响着裂缝的形成与开展(由于内部摩擦引起的),因此,骨料的天然特性(包括与沥青的粘结作用和自身抵抗压碎的能力)对混合料性能的影响很大。该文分析了粗骨料的天然特性对沥青混合料疲劳开裂的影响,采用西班牙格拉纳达大学沥青疲劳开裂试验(UGR-FACT),测试两种不同的沥青混合料试块在不同荷载幅值、频率以及试验温度条件下的开裂性能。试验结果表明:粗骨料的天然特性对沥青混合料的疲劳开裂起到了相当重要的作用,与沥青标号和混合料的矿料组成一样,都是在混合料的设计过程中非常重要的考虑因素。
Asphalt fatigue cracking is one of the most common road disease. In the mix of laboratory mix design, to find the most suitable aggregate to ensure good road performance of the mixture to resist road surface fatigue cracking, it is particularly important. The tensile and shear strengths of asphalt mixtures are mainly provided by their internal cohesion, while the type of asphalt and the strength of asphalt mortar can affect the cohesion. The compressive strength and load carrying capacity of asphalt mixture are mainly provided by the framework of its mineral aggregate. Therefore, the grading curve of aggregates and the shape of aggregate affect the formation and development of fractures (due to internal friction) The natural characteristics (including the bonding with asphalt and its ability to resist crushing) have a significant impact on the properties of the mix. In this paper, the effects of natural properties of coarse aggregate on fatigue cracking of asphalt mixture are analyzed. Asphalt fatigue cracking test (UGR-FACT) of University of Granada, Spain, is used to test the fatigue properties of two different asphalt mixtures at different load magnitudes , Frequency and cracking temperature under test conditions. The experimental results show that the natural characteristics of coarse aggregates play an important role in the fatigue cracking of asphalt mixtures. As with the mineral composition of asphalt grades and mixtures, they are all very important considerations in the design of mixtures .