ABSTRACT

This study comparatively investigated and evaluated three volumetric methods for vertical porosity distribution measurement of pervious concrete pavement: the incremental water displacement method (IWDM), slice-water displacement method (SWDM) with nondemoulding cutting, and computed tomography (CT) scanning method (CTSM). The regional porosity in pervious concrete consolidated by surface compaction increases with the vertical depth, with porosity differences of approximately 10.31%, 8.57%, and 8.80% between the top and bottom regions in the IWDM, CTSM, and SWDM, respectively. Capillary action in the IWDM increases the porosity of the bottom region 120-100 mm from the surface by approximately 0.76% and reduces the porosity of the top region 20-0 mm by approximately 0.75%, but it hardly affects the porosity of 4 other middle regions. The overall porosity determined with the SWDM is very close to that determined with the traditional water displacement method (WDM), with differences of <0.4%, indicating that the knockout effect is almost completely eliminated by the mould protection measure. The CTSM tends to yield a higher overall porosity than that determined with the IWDM, SWDM, and WDM, with average differences of 1.54%, 1.51%, and 1.58%, respectively. The results provide evidence to select the appropriate methods.

摘要

本研究对比研究和评价了透水混凝土路面垂直孔隙率分布测量的三种体积法：增量排水法（IWDM）、非脱模切割切片排水法（SWDM）和计算机断层扫描（CT）扫描法（CTSM） ). 表面压实加固透水混凝土的区域孔隙率随着垂直深度的增加而增加，IWDM、CTSM 和 SWDM 顶部和底部区域的孔隙率差异分别约为 10.31%、8.57% 和 8.80%。IWDM 中的毛细管作用使距表面 120-100 mm 底部区域的孔隙率增加了约 0.76%，并使顶部区域 20-0 mm 的孔隙率降低了约 0.75%，但几乎不影响其他 4 个中间区域的孔隙率地区。SWDM 测得的整体孔隙率与传统水驱法 (WDM) 测得的非常接近，差异 <0.4%，表明模具保护措施几乎完全消除了脱模效应。CTSM 倾向于产生比 IWDM、SWDM 和 WDM 确定的更高的总孔隙率，平均差异分别为 1.54%、1.51% 和 1.58%。结果为选择合适的方法提供了证据。平均差异分别为 1.54%、1.51% 和 1.58%。结果为选择合适的方法提供了证据。平均差异分别为 1.54%、1.51% 和 1.58%。结果为选择合适的方法提供了证据。