ABSTRACT

The foam characteristics that are used to assess the quality of foamed bitumen are conventionally measured manually using a dipstick and stopwatch. Considering the related safety concerns in manual measurement and sensitivity of the performance characteristics of foamed bituminous mixes (FBMs) to the foam characteristics, the present study aimed to improve the process of determining the bitumen foam characteristics during the foaming process. Accordingly, an ultrasonic sensor system which is capable of automatic non-contact measurement of foam characteristics was developed. The capability of the proposed method in terms of producing repeatable results was evaluated based on repeatability limit, Analytical Performance Value (APV) and coefficient of variation (CV). The study results indicate that the ultrasonic sensor system is very promising in terms of its ability to provide a detailed history of the change of volume of foamed bitumen with time with high repeatability. Conversely, the repeatability of the manual method of measurement was found to be very low at all most all foaming conditions. In addition, to eliminate any possibility of error in determining the foam characteristics obtained from the ultrasonic sensor system, a data analysis algorithm was recommended to analyse the bitumen foam height profile data collected from the device.

摘要

用于评估泡沫沥青质量的泡沫特性通常使用量油尺和秒表手动测量。考虑到人工测量的相关安全问题以及泡沫沥青混合料（FBM）的性能特征对泡沫特征的敏感性，本研究旨在改进在发泡过程中确定沥青泡沫特征的过程。因此，开发了一种能够自动非接触测量泡沫特性的超声波传感器系统。基于重复性极限、分析性能值 (APV) 和变异系数 (CV) 评估了所提出方法在产生可重复性结果方面的能力。研究结果表明，超声波传感器系统在提供具有高重复性的泡沫沥青体积随时间变化的详细历史记录方面非常有前景。相反，发现手动测量方法的可重复性在几乎所有发泡条件下都非常低。此外，为了消除在确定从超声波传感器系统获得的泡沫特性时出现任何错误的可能性，建议使用数据分析算法来分析从设备收集的沥青泡沫高度剖面数据。