Carbonation resistance and service life estimation of concrete incorporating paraffin-functionalized recycled aggregates

Abstract

The carbonation process is a critical factor affecting the long-term durability of concrete structures. This study proposes a novel approach to enhance the carbonation resistance of concrete by functionalizing recycled aggregates with paraffin wax and using them as partial or full replacements (0%, 25%, 50%, 75%, and 100%) for natural aggregates. Accelerated carbonation tests over 180 days were conducted to investigate the relationships among physical properties, mechanical behavior, and carbonation performance, as well as to determinate the carbonation resistance and estimate the service life. The results presented that concrete containing 100% recycled aggregates exhibited reductions of 60.2% in carbonation resistance and 73.2% in service life estimation compared with reference concrete. In contrast, concrete incorporating 75% and 100% functionalized recycled aggregates demonstrated undetectable carbonation under accelerated conditions. These findings underscore the potential of such sustainable materials to improve both the durability and sustainability of concrete structures.