ABSTRACT

The issue of alkali-pumping has emerged in recent years raising concerns on the quality of the newly constructed asphalt pavement. To understand alkali-pumping and its effects, we conducted two-year on-site inspection of a pavement and analysed the mineral composition of alkali-pumping. The water permeability, void characteristics, and water stability of the asphalt pavement with and without alkali-pumping were tested and compared. Then, we preliminary analysed the mechanisms. Furthermore, the probability of the alkali-pumping and its control method. Lastly, 3D ground-penetrating radar was utilised for analysing the relationship between the dielectric constant and the distribution of alkali-pumping. Subsequently, dielectric constant thresholds corresponding to alkali-pumping were established. The results showed that alkali-pumping is caused by the segregation of the pavement and the leakage of alkali elements. Furthermore, the dielectric constants with and without alkali-pumping were significantly different, and their spatial distribution was well correlated with the occurrence of alkali-pumping. Finally, it was determined that asphalt pavements with a dielectric constant smaller than 3.5 are likely to experience alkali-pumping, while those with a dielectric constant between 3.5 and 6.5 are unlikely to experience alkali-pumping, and in those with a dielectric constant greater than 6.5, the probability of alkali-pumping is negligibly small.

摘要

近年来出现了碱泵问题，引起人们对新建沥青路面质量的关注。为了了解碱泵及其影响，我们对路面进行了为期两年的现场检查，并分析了碱泵的矿物成分。测试并比较了有碱和无碱的情况下沥青路面的透水性，空隙率和水稳定性。然后，我们初步分析了机制。此外，碱抽的可能性及其控制方法。最后，利用3D探地雷达分析了介电常数与碱泵分布之间的关系。随后，建立对应于碱泵浦的介电常数阈值。结果表明，碱抽是由于路面的偏析和碱元素的泄漏引起的。此外，有和没有碱抽运时的介电常数都存在显着差异，并且它们的空间分布与碱抽运的发生有很好的相关性。最后，确定介电常数小于3.5的沥青路面很可能会经历碱泵送，而介电常数介于3.5和6.5之间的沥青路面不太可能会经历碱泵送，而介电常数大于3.5 6.5。抽碱的可能性很小。它们的空间分布与碱泵的发生有很好的相关性。最后，确定介电常数小于3.5的沥青路面很可能会经历碱泵送，而介电常数介于3.5和6.5之间的沥青路面不太可能会经历碱泵送，而介电常数大于3.5 6.5。抽碱的可能性很小。它们的空间分布与碱泵的发生有很好的相关性。最后，确定介电常数小于3.5的沥青路面很可能会经历碱泵送，而介电常数介于3.5和6.5之间的沥青路面不太可能会经历碱泵送，而介电常数大于3.5 6.5。抽碱的可能性很小。