Influence of mineral admixtures on carbonation curing of cement paste

CO2 Uptake and Physicochemical Properties of Carbonation-Cured Ternary Blend Portland Cement–Metakaolin–Limestone Pastes

“…The ML30 and ML45 samples showed declined compressive strengths upon an increment in the carbonation durations. The reduction in the compressive strength of the blended samples upon carbonation can be attributed to their increased overall porosity (explained in Section 3.5 ) and reduced amount of portlandite upon higher replacement of PC [ 42 ]. Zhang et al [ 20 ] described that pozzolanic reaction is hindered by the early carbonation curing.…”

“…Intensity of portlandite peaks was observed to be decreased for the OPC-L sample in comparison to the OPC-W sample, which further decreased in the OPC-M and OPC-H samples. Reduction in portlandite peak intensity verifies the conversion of portlandite to calcite due to the carbonation curing [ 42 ]. For blended samples, portlandite peaks were observed to be reduced in intensity with increase in the carbonation duration.…”

“…In contrast, increase in sorptivity coeficients was observed for ML30 and ML45 samples with increase in carboantion curing durations. Qin et al [ 42 ] reported an increase in the total porosity of blended systems upon carbonation curing. In general, carbonation of portlandite reduces the porosity of PC-based systems, but in systems where portlandite quantity is low due to pozzolanic reaction and reduced clinker content, carbonation of C-S-H takes place which coarsens the porosity [ 53 ].…”

“…Carbonation curing of PC-based materials has been extensively studied during the last decade [ 3 , 14 , 16 , 19 , 21 ]. Studies on the effect of mineral admixtures on carbonation curing suggest that mineral admixtures can enhance CO 2 uptake [ 20 , 40 , 41 , 42 ], particularly a study conducted by Zhang et al [ 20 ] showed that higher levels (50%) of substitution by fly ash can further improve the CO 2 uptake capacity. To the authors’ knowledge, however, the carbonation curing of the LC 3 systems has never been tested.…”

The effect of CO2 on cement composites produced with an admixture of waste sludge water from a concrete plant

“…The formation of CaCO3 after curing by means of carbonation has improved the pore structure and has shown higher efficiency for pore filling. That is why carbonation curing provides a good way how to efficiently recycle industrial wastes as mineral additives [5][6][7]. The samples exposed to the effect of CO2 show a denser microstructure compared to the samples not exposed to CO2.…”