Assessing Damage, Sorptivity, Air Content, and Strength of Portland Cement Concrete Pavements in Indiana

Abstract

A field condition assessment was performed for selected portland cement concrete pavements (PCCP) in the state of Indiana. Five pavement sections (including a 25 year old un-trafficed section) were selected based on age, traffic, and overall performance. After a field survey and site inspection, cores were taken from these pavements and used for laboratory analysis. The cores were visually inspected, after which they were sectioned and used for air void analysis, microscopic investigation of cracking, water absorption, and splitting tensile strength. Large irregular air voids were observed in each pavement core. The hardened concrete air content was observed to vary both between the different pavement sections and between the top and bottom layers of the pavement. In addition, the hardened air content in the pavements was found to vary from 4 to 13% by volume. Micro-cracks were observed in some pavements that appeared at the aggregate paste interface, through weak aggregates, and around air voids. In damaged pavements, the sorptivity of the top layer of the pavement was higher than that of the middle or bottom layer. The magnitude of variation in sorptivity appears to be related to the age and performance of the pavement. This is in agreement with the results from laboratory-cured specimens, in which freeze and thaw damage influences both the short-term and longterm sorptivity of concrete.