Effects of Carbonation on the Microstructure of Cement Materials: Influence of Measuring Methods and of Types of Cement

Abstract

The objective of this work was to examine the influence of carbonation on the microstructure of cement materials. Different materials, which were CEM I mortar and paste, CEM II mortar and paste, were carbonated at 20°C, 65 % relative humidity and 20 % of CO 2 concentration. The specific surface area and pore size distribution were determined from two methods: nitrogen adsorption and water adsorption. The results showed that: (1) nitrogen adsorption and water adsorption do not cover the same porous domains and thus, we observed conflicts in the results obtained by these two techniques; (2) the CEM II based materials seemed to be more sensible to a creation of mesoporosity after carbonation than the CEM I based materials. The results of this study also helped to explain why observations in the literature diverge greatly on the influence of carbonation on specific surface area.

Physical and Mechanical Properties of Cementitious Specimens Exposed to an Electrochemically Derived Accelerated Leaching of Calcium

“…This will result in dissolution or precipitation of minerals, and consequently in alteration of the microstructure as well as the chemical and mineralogical composition of the cementitious materials. There are a lot of concerns in normal constructions such as chloride corrosion of the reinforcement, carbonation or sulfate attack (Morga and Marano 2015;Park and Choi 2012;Pham and Prince 2014;Pritzl et al 2014), however, here the most important process is the decalcification of the material through the dissolution of the calcium hydrates (Portlandite Ca(OH) 2 and the Calcium silicate hydrates (CSH) phases, which constitute the major portion of hydrated cementitious material (Hinsenveld 1992).…”

Analysis of Fine Sulfoaluminate Cement by Strength and Thermogravimetric Analysis

“…More Gibbsite and Ettringite contents are shown by a 20% partial replacement sample [16]. After a 2hrs carbonation attack, the TGA results were analyzed as done by previous researches [17][18][19]. In SAC samples, the CaCo3 decomposition ranges are compared by DTG curves.…”

The effects of cement-based and cement-ash-based mortar slabs on indoor air quality

“…The sink effect can be explained by the fact that the mortars represent a strong base, which attracts acids. They have a particularly high pH when freshly cast (Pham and Prince, 2014) though with time, as the mortar matures, its alkalinity decreases and pH neutralizes due to a carbonation process that forms calcium carbonate. This suggests that the potential for adsorbing organic acids could decrease with time.…”