{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/115952"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/115952","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Raman imaging of cementitious carbonation: A spatio-temporal investigation","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-08-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-08-01","abstract_has_math":false,"creators":["Srivastava, Sonali"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Civil Engineering","degree_department":null,"school":null,"contributors":["Garg, Nishant"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-08","date_published":"2022-08","updated_at":"2026-07-22T22:24:55Z","subjects":["Cement","Carbonation","Raman spectroscopy"],"languages":["en","eng"],"rights":["Copyright 2022 Sonali Srivastava"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/115952","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Garg, Nishant"]},{"key":"dc:creator","label":"Author","values":["Srivastava, Sonali"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2022-08","2022-07-19"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Cement","Carbonation","Raman spectroscopy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2022 Sonali Srivastava"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/115952"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-08-01","The student, Sonali Srivastava, accepted the attached license on 2022-07-19 at 14:17.","The student, Sonali Srivastava, submitted this Thesis for approval on 2022-07-19 at 14:19.","This Thesis was approved for publication on 2022-07-19 at 16:21.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18377 on 2022-11-16 at 10:56:33","To reduce the carbon dioxide emission to 43% by 2030 set by United Nations IPCC’sixth assessment, several steps are taken by cement-based industries. Among them, carbon dioxide sequestration and utilization using cement and concrete-based materials are getting attention. Carbon-rich hydrated cement products have huge potential in absorbing anthropogenic carbon dioxide from the atmosphere and leading us to a carbon-neutral environment. With this state of-art advancement, studying and quantifying carbon absorption is vital. Several methods such as pH indicators, thermogravimetry analysis (TGA), and X-ray diffraction (XRD) have been used to study carbonation in cement. However, these existing methods are either very primi tive (pH test) or require intensive sample preparation. Methods like TGA and XRD are bulk methods that require the crushing of samples. Also, none of the above-mentioned methods provide advection and depth growth during carbonation. Moreover, because of the complexity of cement’s hydrates and carbonates, estimating the carbonated products are still little under stood. With all the limitations, there is room for developing a complementary non-destructive tool that can investigate carbonation over space and time. This work uses confocal Raman spectroscopy to understand the spatially and temporally carbonated products formed during carbonation (advection and depth study). High-resolution mapping of calcium carbonate and calcium hydroxide is used to study a dynamic phenomenon. It is observed that the calcite precipitation is not only around portlandite but also around the initial limestone. This suggests that limestone filler in cement acts as a nucleation site for precipitation of calcite from portlandite carbonation. Moreover, the thin carbonated layer formed around portlandite crystals can slow down further carbonation. Also, calcium hydroxide is not only the hydration product reacting with CO2. From Raman spectra of calcium hydroxide, it is clear that the decrease in calcium hydroxide is not as drastic as the increase in calcium carbonate; these results are evidence that other hydration products like calcium silicate hydrate (C-S-H) and ettringite are also potentially contributing significantly towards carbonation. After nearly two weeks of carbonation exposure, the final saturation in terms of area covered by calcite growth is around 40%. Furthermore, for the depth study, a cost-effective method is opted using a hand-held Raman probe. Carbonation depth can be measured by observing the occurrence of the C-O characteristic vibration peak at 1086 cm−1 when the signal-to-noise ratio is ≥ 3. The carbonation front measured from the phenolphthalein indicator is lower than the depth measured using Raman spectroscopy. Also, a high water-cement ratio leads to higher carbonate contents and increases carbonation depth. The initial curing and pre-treatment of cement are crucial for the carbonation process."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Raman imaging of cementitious carbonation: A spatio-temporal investigation"]}]}],"canonical_facts":{"dc:contributor":["Garg, Nishant"],"dc:creator":["Srivastava, Sonali"],"dc:date":["2022-08","2022-07-19"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-08-01","The student, Sonali Srivastava, accepted the attached license on 2022-07-19 at 14:17.","The student, Sonali Srivastava, submitted this Thesis for approval on 2022-07-19 at 14:19.","This Thesis was approved for publication on 2022-07-19 at 16:21.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18377 on 2022-11-16 at 10:56:33","To reduce the carbon dioxide emission to 43% by 2030 set by United Nations IPCC’sixth assessment, several steps are taken by cement-based industries. Among them, carbon dioxide sequestration and utilization using cement and concrete-based materials are getting attention. Carbon-rich hydrated cement products have huge potential in absorbing anthropogenic carbon dioxide from the atmosphere and leading us to a carbon-neutral environment. With this state of-art advancement, studying and quantifying carbon absorption is vital. Several methods such as pH indicators, thermogravimetry analysis (TGA), and X-ray diffraction (XRD) have been used to study carbonation in cement. However, these existing methods are either very primi tive (pH test) or require intensive sample preparation. Methods like TGA and XRD are bulk methods that require the crushing of samples. Also, none of the above-mentioned methods provide advection and depth growth during carbonation. Moreover, because of the complexity of cement’s hydrates and carbonates, estimating the carbonated products are still little under stood. With all the limitations, there is room for developing a complementary non-destructive tool that can investigate carbonation over space and time. This work uses confocal Raman spectroscopy to understand the spatially and temporally carbonated products formed during carbonation (advection and depth study). High-resolution mapping of calcium carbonate and calcium hydroxide is used to study a dynamic phenomenon. It is observed that the calcite precipitation is not only around portlandite but also around the initial limestone. This suggests that limestone filler in cement acts as a nucleation site for precipitation of calcite from portlandite carbonation. Moreover, the thin carbonated layer formed around portlandite crystals can slow down further carbonation. Also, calcium hydroxide is not only the hydration product reacting with CO2. From Raman spectra of calcium hydroxide, it is clear that the decrease in calcium hydroxide is not as drastic as the increase in calcium carbonate; these results are evidence that other hydration products like calcium silicate hydrate (C-S-H) and ettringite are also potentially contributing significantly towards carbonation. After nearly two weeks of carbonation exposure, the final saturation in terms of area covered by calcite growth is around 40%. Furthermore, for the depth study, a cost-effective method is opted using a hand-held Raman probe. Carbonation depth can be measured by observing the occurrence of the C-O characteristic vibration peak at 1086 cm−1 when the signal-to-noise ratio is ≥ 3. The carbonation front measured from the phenolphthalein indicator is lower than the depth measured using Raman spectroscopy. Also, a high water-cement ratio leads to higher carbonate contents and increases carbonation depth. The initial curing and pre-treatment of cement are crucial for the carbonation process."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/115952"],"dc:language":["en","eng"],"dc:rights":["Copyright 2022 Sonali Srivastava"],"dc:subject":["Cement","Carbonation","Raman spectroscopy"],"dc:title":["Raman imaging of cementitious carbonation: A spatio-temporal investigation"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Civil Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:55Z"}