Carbonation-decarbonation of concretes studied by the way of carbon and oxygen stable isotopes

Rafai, Nourredine; Lètolle, René; Blanc, Philippe; Gégout, Philippe; Revertégat, E.

doi:10.1016/0008-8846(92)90112-9

Cited by 18 publications

(9 citation statements)

References 3 publications

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“…These lines comprise ideal mortar layers representing continues calcite formation with continues enrichment of 18 O versus 16 O and 13 C vs 12 C in the CO2 gas phase and the precipitated calcite. It appears that the quantity percentage and the quality of the charge do not influence significantly the 13 C of The isotopic composition of calcite from mortar represent non-isotopic equilibrium [19,20,[41][42][43][44][45] and depends mainly on the isotopic composition of atmospheric CO 2 and water and on the degree to which the isotopic equilibrium is reached and therefore the factor of fractionation of δ 13 C CaCO 3 −δ 13 C CO 2 −δ 18 O CO 2 and δ 18 O H 2 O . In order to define the isotopic values for a pure calcite precipitated in alkaline environment using local meteoric water and atmospheric CO 2 , the isotopic values of local water in each sampling area are analyzed.…”

Section: Evaluation Of Setting Environments and Processesmentioning

confidence: 99%

δ13C and δ18O Stable Isotope Analysis Applied to Detect Technological Variations and Weathering Processes of Ancient Lime and Hydraulic Mortars

et al. 2018

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Samples of mortars were collected from lime and hydraulic mortars affected by environmental degradation. A total of 63 samples were obtained from Hellenistic, Late Roman and Byzantine historic constructions located at Kavala, Drama and Makrygialos in North Greece. Samples were collected in sections from the surface up to 6 cm deep using a drill-core material. The first sample was collected from the external layer, while the internal samples were collected each 1cm beeper from the previous, in order to monitor the moisture ingress. Isotopic data will make it possible to create an ideal Hellenistic and Byzantine mortar layer and to provide weathering gradients. The isotopic values comprise a range of δ13C and δ18O values from −17.1‰ to 1.2‰ and −25.9‰ to −2‰, respectively. The weathering process of Hellenistic and Byzantine are expressed, by the regression lines δ18Ocalcite matrix = 0.6 × δ13Ccalcite matrix − 1.9 and δ18Ocalcite matrix = 0.6 × δ13Ccalcite matrix − 2.0 for hydraulic and Lime mortars respectively. Pronounced isotopic shift to heavy or light δ13C and δ18O in the carbonate matrix was attributed to the primary source of CO2 (atmospheric versus biogenic) and H2O (evaporation of local primary water), in residual limestone and in secondary processes such as recrystallization of calcite with pore water and salts attack. Exogenic processes related to biological growth are responsible for further alterations of δ18O and δ13C in lime mortars. This study indicated that stable isotope analysis is an excellent tool to fingerprint the origin of carbonate, the environmental setting conditions of mortar, origin of CO2 and water during calcite formation and to determine the weathering depth and the potential secondary degradation mechanisms.

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Section: Evaluation Of Setting Environments and Processesmentioning

confidence: 99%

δ13C and δ18O Stable Isotope Analysis Applied to Detect Technological Variations and Weathering Processes of Ancient Lime and Hydraulic Mortars

et al. 2018

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“…where for C and O isotopes R is 13 Table 1. Chemical composition of the binder (matrix of the mortar) from horizons E, D, B-1, and B-2 analysed along the profile of the cistern lining at the given depths (see Figure 1).…”

Section: Methodsmentioning

confidence: 99%

“…The information about the chemical composition and distribution of stable carbon and oxygen isotopes of the calcium carbonate binder is a powerful tool to elucidate the environmental conditions of its formation and subsequent transformation [3,[10][11][12][13][14][15][16]. However, the combined isotopic and micro-chemical investigations of an entire profile of hydraulic lime mortar are sparse.…”

Section: Introductionmentioning

confidence: 99%

Tracing formation and durability of calcite in a Punic–Roman cistern mortar (Pantelleria Island, Italy)

Dietzel

Schön

Heinrichs

et al. 2015

Isotopes in Environmental and Health Studies

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Ancient hydraulic lime mortar preserves chemical and isotopic signatures that provide important information about historical processing and its durability. The distribution and isotopic composition of calcite in a mortar of a well-preserved Punic-Roman cistern at Pantelleria Island (Italy) was used to trace the formation conditions, durability, and individual processing periods of the cistern mortar. The analyses of stable carbon and oxygen isotopes of calcite revealed four individual horizons, D, E, B-1 and B-2, of mortar from the top to the bottom of the cistern floor. Volcanic and ceramic aggregates were used for the production of the mortar of horizons E/D and B-1/B-2, respectively. All horizons comprise hydraulic lime mortar characterized by a mean cementation index of 1.5 ± 1, and a constant binder to aggregate ratio of 0.31 ± 0.01. This suggests standardized and highly effective processing of the cistern. The high durability of calcite formed during carbonation of slaked lime within the matrix of the ancient mortar, and thus the excellent resistance of the hydraulic lime mortar against water, was documented by (i) a distinct positive correlation of δ(18)Ocalcite and δ(13)Ccalcite; typical for carbonation through a mortar horizon, (ii) a characteristic evolution of δ(18)Ocalcite and δ(13)Ccalcite through each of the four mortar horizons; lighter follow heavier isotopic values from upper to lower part of the cistern floor, and (iii) δ(18)Ocalcite varying from -10 to -5 ‰ Vienna Pee Dee belemnite (VPDB). The range of δ(18)Ocalcite values rule out recrystallization and/or neoformation of calcite through chemical attack of water stored in cistern. The combined studies of the chemical composition of the binder and the isotopic composition of the calcite in an ancient mortar provide powerful tools for elucidating the ancient techniques and processing periods. This approach helps to evaluate the durability of primary calcite and demonstrates the importance of calcite as a proxy for chemical attack and quality of the ancient inorganic binder.

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“…The carbonated front moves faster (and deeper) at 140°C than at 90°C. As the connected porosity exhibits a similar value for both materials (about 30%), and the CO 2 solubility is similar in pure water at 90°C and 140°C (Figure 3), the difference may stem from the mineralogical nature of the hydrates that react with the dissolved CO 2 , their proportion and microstructural assemblage [Rafai, 1992] (e.g. no portlandite in the cement used for test #2 with silica flour and 140°C).…”

Section: X -S Y -H Z + Xh 2 Co 3 → Xcaco 3 + Ysio 2 Th 2 O + (X-t+mentioning

confidence: 96%

CO2-Induced Changes in Oilwell Cements Under Downhole Conditions: First Experimental Results

Garnier

Laudet

Neuville

et al. 2010

SPE Annual Technical Conference and Exhibition

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One of the major technological issues for CO 2 injection (for EOR, CCS, etc.) is the long-term behavior of cement-based materials used to ensure the overall sealing performance of the storage wells. When water is present, the CO 2 after injection can react chemically with the cement (i.e. carbonation). How do the CO 2 -enriched formation fluids changes the cement's chemistry and properties? Could the sealing efficiency of the wells be affected by these changes?The objectives of our experimental program are to assess the kinetics and phenomenology of the changes that occur in different class-G Portland cements exposed to CO 2 -enriched aqueous fluids at 8 MPa and two different temperatures.The experimental program presented in this paper consists of: a first carbonation test (Test # 1) using neat G cement, at a temperature of 90°C (194° F) and a pressure (supercritical CO 2 above water) of 8 MPa (1160 psi); a second carbonation test (Test # 2) using G cement with silica flour (to prevent strength retrogression), at a temperature of 140°C (284°F) and at the same CO 2 pressure of 8Mpa. Finally, coupled chemo-mechanical tests (dynamic tests) are underway on similar class-G cement and similar CO 2 -rich water.All the samples were prepared according to ISO/API specifications. The experimental set-up simulates downhole "static" conditions: the samples were immersed in water in a cell thermally regulated and pressurized by CO 2 . Cement samples were exposed to CO 2 -saturated water for various lengths of time (from one week to 3 months) and were characterized using advanced methods for chemical and mineralogical analysis (X-ray tomography, SEM, XRD, TGA-TDA…) and mechanical testing.The main preliminary results show a reactive front (characterized by carbonation) progressing from the fluid-sample interface towards the sample centre. The carbonation front moves faster during Test 2 (at higher temperature) than during Test 1 (at lower temperature). SEM images of Test 2 also show a thin layer of dissolved carbonate at the sample's surface. The carbonated cement areas exhibit increased density and greater compressive strength.The results of coupled chemo-mechanical tests with injection of CO 2 -enriched water in samples under deviatoric stress show that the CO 2 flow rate in the cement rapidly decreases, finally resulting in carbonation clogging of the cement sample. These results seem consistent with reported field observations.

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Carbonation-decarbonation of concretes studied by the way of carbon and oxygen stable isotopes

Cited by 18 publications

References 3 publications

δ13C and δ18O Stable Isotope Analysis Applied to Detect Technological Variations and Weathering Processes of Ancient Lime and Hydraulic Mortars

δ13C and δ18O Stable Isotope Analysis Applied to Detect Technological Variations and Weathering Processes of Ancient Lime and Hydraulic Mortars

Tracing formation and durability of calcite in a Punic–Roman cistern mortar (Pantelleria Island, Italy)

CO2-Induced Changes in Oilwell Cements Under Downhole Conditions: First Experimental Results

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