X-Ray Computed Tomography and Nondestructive Evaluation of Clogging in Porous Concrete Field Samples

Abstract

This study aims to investigate and quantify the fraction of clogging in pervious concrete samples cored from parking lots. Image observation, analysis, and processing of representative cores retrieved from parking lots enabled qualitative relation of porosity with clogging. Porosity profiles obtained from processing of computed tomography (CT) scanned images were used to assess the nature and extent of clogging. Significantly lower porosity values were computed for old cores compared to newer ones. It was also observed that samples manifested clogged behavior because of high cement paste (mortar) content. Porosities of samples were calculated, for comparison using a gravimetric method and the clogged fraction in the cores was quantified by recalculating porosities of specimens scanned after vacuum cleaning. X-ray CT scanning proved a useful tool to study clogging, and the clogged fraction varied from 1.48% in sample PL 12-1 to 11.15% in sample QP 45-3.