Effect of supplementary cementitious materials on the resistance of cement paste to carbonic acid water

Abstract

Cement pastes blended with fly ash or slag suffering from carbonic acid water were investigated. Thermogravimetric analysis was performed to determine the effect of fly ash and slag on CH content in cement pastes. Mercury intrusion porosimetry was used to characterize the effect of fly ash and slag on pore structure of cement pastes. Decalcification shrinkage and corrosion depth were determined to characterize the deterioration of cement paste after corrosion. The results show that the decalcification shrinkage is related to the initial CaO content and the composition of CSH gel. The corrosion depth depends on its initial CH content and pore structure. The results show that the paste blended with both fly ash and slag has good resistance to carbonic acid water in terms of decalcification shrinkage (reduced by nearly one half compared by the largest one) together with corrosion depth (reduced by nearly one third compared by the largest one). Furthermore, H2CO3 diffusion coefficient of the paste as a function of time was determined, which can be used to predict the durability of the pastes.

Basalt powder as a supplementary cementitious material in cement paste for CCS wells: chemical and mechanical resistance of cement formulations for CO2 geological storage sites

“…Furthermore, cement formulations with higher water-to-solids ratio, BP 0.25 (W/S = 0.439) and BP 0.50 (W/S = 0.438), have greater resistance to carbonation than samples with higher density: BP 1.00 (W/S = 0.436), BP 2.50 (W/S = 0.429) and BP 5.00 (W/S = 0.419). From these results, we found that cement formulations with low basalt powder content (≤ 0.50 wt.%) shows the best chemical resistance to CO 2 , confirming the literature statement that even small SCM additions can significantly alter the properties of the cement paste (Ghafari et al, 2016;Lothenbach et al, 2011;Paris et al, 2016;Yin et al, 2018). However, the literature argues that cement formulations with higher density are expected to have greater resistance to carbonation (Costa et al, 2019;Torsaeter et al, 2013).…”

“…After identifying the morphological and surface characteristics of the basalt powder, the mineral composition of the raw material was characterized by means of XRD (Table 2 and Figure S3). The mineral composition of SCM defines its reactivity during the hydration process, the role performed by the additive in the cement formulation, and indicates which are the mineral phases that will be generated after the curing process (Lothenbach et al, 2011;Paris et al, 2016;Yin et al, 2018).…”

“…Thus, once the drilling of the well progresses to deeper reservoirs, with more adverse pressure and temperature conditions, it is necessary to develop new cement formulations that can meet design requirements and are able to resist a long-term exposure to CO 2 (Iyer et al, 2018;Omosebi et al, 2016;Postma et al, 2019;Wang et al, 2017). Among the most common strategies for changing cement properties is the use of SCM in paste formulations, which alter the composition of the cement minerals, its porous structure, and the material's chemical and mechanical resistance (Abid et al, 2020;Ghafari et al, 2016;Ledesma et al, 2020;Lothenbach et al, 2011;Paris et al, 2016;Tiong et al, 2019;Yin et al, 2018). These novel formulations must be studied under appropriate conditions, similar to those found in the CCS storage site, in order to assess the extent of the CO 2 degradation process and guarantee the wellbore integrity throughout its life cycle, thereby avoiding or delaying the need for workover operations (Abid et al, 2020;Costa et al, 2019;Dong et al, 2020;Szabó-Krausz et al, 2020;Teodoriu and Bello, 2020).…”

“…Research on evaluating the chemical and mechanical properties of cement formulations modified by SCM against degradation due to CO 2 is limited, and only a few SCMs have been evaluated (Abid et al, 2020;Ledesma et al, 2020;Yin et al, 2018). However, it is recognized that even a small amount of SCM can result in a change in the amount and type of hydration products formed in the cement matrix, and can promote a refinement of the porous structure, which could delay the carbonation process and improve the wellbore integrity (Ghafari et al, 2016;Lothenbach et al, 2011;Paris et al, 2016;Yin et al, 2018). Furthermore, there is no consensus solution on the use of SCM (conventional or unconventional) in cement formulations to reduce the effect of acid gases (Tiong et al, 2019).…”

Carbonation Behaviors of Recycled Concrete Fines Containing Supplementary Cementitious Materials: Compositions, Microstructures, and Mechanisms

“…25,26 Although the effect of accelerated carbonation treatment on RCAs originating from blended concrete has not been sufficiently investigated, information on the carbonation resistance of blended cement systems as part of the durability properties is widely available. For example, it was reported by Morandeau et al 27 and Yin et al 28 that carbonating cement paste with increasing FA content resulted in increased carbonation depth, showing almost a linear relationship and a pore coarsening effect was observed. Meanwhile, GS-blended concrete was found to have a higher carbonation resistance than plain concrete because of the denser microstructure that was less permeable to CO 2.…”