Effects of fine Aggregates, Cicopowder-WP, and Styrene-Butadiene rubber on carbonation resistance in concrete

Abstract

Reinforced concrete is the most common construction material used in buildings, bridges, and other infrastructure elements. Corrosion or rust plays a significant role in determining the durability of reinforced concrete. Corrosion decreases the safety and service lifetime of reinforced concrete, which, in turn, increases maintenance costs. Concrete is an alkaline media that forms a passive film over steel bars to prevent corrosion. Carbonation is the most prominent cause of a loss of alkalinity in concrete. Therefore, this paper investigates the effect of fine aggregates and additives on concrete’s resistance to carbonation or carbon dioxide (CO2) penetration in concrete. It is also examined whether the two sizes of fine aggregates, Cicopowder-WP (CICO), and styrene-butadiene rubber (SBR) as additives can strengthen concrete. The results reveal that CO2 penetration in concrete decreases gradually by adding, in order of effectiveness, (1) fine aggregate (sand only), (2) two sizes of fine aggregates (sand and 5 mm), (3) CICO, and (4) SBR. Consequently, the compressive strength of concrete and the lifetime of the passive film increase gradually following the same sequence.