Mechanical properties of carbonated concrete

Abstract

In this paper, mechanical properties of carbonated concrete were studied. Compressive strength, splitting tensile strength, elastic modulus, bond strength and hardness for carbonated concrete subjected to various carbonation conditions were evaluated. Experimental results indicated that all these mechanical properties showed a higher value after carbonation. Especially the bond strength for fully carbonated concrete was about 1.7 that for uncarbonated concrete. Hardness experiments showed that concrete 0.5 cm deeper than the carbonation depth, measured by the method of RILEM CPC-18, had a hardening effect due to carbonation products. It was found that enhancement of compressive strength was more significant if the carbonation and the loading directions were orthogonal. SEM photos showed that limestone was formed after carbonation, which is the main reason for changes in mechanical properties.