發(fā)布時間：2019-02-19 12:59

【摘要】：為了研究關鍵因素對密級配瀝青混凝土低溫斷裂性能的影響,采用離散單元法(DEM)和三維顆粒流程序PFC3D模擬彎曲斷裂試驗.基于隨機生成算法和虛擬不規(guī)則粗集料庫模擬集料級配和不規(guī)則形狀、瀝青砂漿以及空隙率的生成過程.然后,在虛擬試件中添加細觀力學接觸本構模型進行虛擬斷裂試驗,虛擬試驗結果與室內(nèi)試驗結果對比驗證了虛擬試驗結果的有效性.此外,基于虛擬仿真采用正交試驗研究集料和空隙的體積分數(shù)、集料和瀝青砂漿的剛度、瀝青砂漿內(nèi)部粘結強度以及集料和空隙的分布對虛擬斷裂試驗的影響.研究表明,上述因素對斷裂性能都有不同程度的影響,其中對彎拉強度和彎曲應變能密度影響最大的是瀝青砂漿的粘結強度,對彎拉應變影響最大的是粗集料的體積分數(shù).為了得到較好的密級配瀝青混合料低溫斷裂性能,考慮瀝青砂漿和集料的細觀結構非常重要.
[Abstract]:In order to study the influence of key factors on the low-temperature fracture behavior of dense graded asphalt concrete, the bending fracture test was simulated by discrete element method (DEM) and three-dimensional particle flow program (PFC3D). Based on random generation algorithm and virtual irregular coarse aggregate library, the formation process of aggregate gradation and irregular shape, asphalt mortar and voids are simulated. Then, the virtual fracture test is carried out by adding the meso-mechanical contact constitutive model to the virtual specimen. The virtual test results are compared with the results of the laboratory test to verify the validity of the virtual test results. In addition, the effects of volume fraction of aggregate and void, stiffness of aggregate and asphalt mortar, internal bond strength of asphalt mortar and distribution of aggregate and void on virtual fracture test were studied by orthogonal test based on virtual simulation. The results show that the above factors have different effects on the fracture properties, among which the binder strength of asphalt mortar and the volume fraction of coarse aggregate have the greatest influence on flexural tensile strength and flexural strain energy density. It is very important to consider the meso-structure of asphalt mortar and aggregate in order to obtain better low-temperature fracture performance of dense gradation asphalt mixture.
【作者單位】： 東南大學交通學院;南京工程學院建筑工程學院;
【基金】：The National Natural Science Foundation of China(No.51378006,51378121)
【分類號】：U414
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本文編號：2426522