Relation between carbonation resistance, mix design and exposure of mortar and concrete

Influence of cement type on carbonation of concrete mixtures

“…The carbonation depth measured on mixture C5 produced with higher w/c ratio was almost twice the one performed by mixtures C1 and C3 (Table 6). Increased vulnerability of blended cement concretes produced with higher w/c ratios is in accordance of findings of other researches [5,6].…”

Experimental studies and thermodynamic modeling of the carbonation of Portland cement, metakaolin and limestone mortars

“…This lower amount of portlandite may account for the faster carbonation process for Portland cement -SCM blends, compared to pure Portland cement, as mentioned in earlier studies [10,11]. However, it seems of minor importance for the carbonation resistance, if the CaO buffering the ingression of CO 2 is present in portlandite or in C-S-H [12]. A decisive material parameter for the carbonation resistance is the buffer capacity per volume of cement paste that can be expressed as the ratio between mixing water and CaO reacting with CO 2 [12].…”

“…This problem may become particularly important when SCMs are incorporated in cement blends, since several studies have reported that cement-based materials including SCMs exhibit poor carbonation resistance, e.g. [10][11][12]. This underlines the research needs for carbonation studies of Portland cement -calcined clay -limestone blends before an industrial realization of these materials can take place.…”

A natural cement analogue study to understand the long-term behaviour of cements in nuclear waste repositories: Maqarin (Jordan)

“…Carbonation is a common process observed in mortars and concrete exposed to atmospheric CO 2 or dissolved CO 2 or HCO 3 2À in groundwater. Cement hydrates phases are known to readily react with CO 2 and moisture, and are transformed to CaCO 3 and a silica-rich gel containing some aluminium (Groves et al, 1991;Bary and Sellier, 2004;Leemann et al, 2015). The kinetics of natural carbonation is dependent on relative humidity, with maximum rates between 55 and 75% (Wierig, 1984).…”