Optimal Pre-hydration Age for CO2 Sequestration through Portland Cement Carbonation
- University of Michigan, Ann Arbor, MI (United States)
An emerging technology of CO2 sequestration in Portland cement (PC) is through accelerated carbonation, where PC is intentionally carbonated at early hydration age and reinitiates long-term hydration upon completion of carbonation. However, the current literature has overlooked a fact that different PC hydration ages prior to carbonation (pre-hydration) could lead to distinct carbonation efficiencies and subsequent hydration behaviors (post-hydration). Here, we examine the effects of length of pre-hydration period on CO2 uptake and on the hydration extent and final strength at 28 days. The CO2 and H2O profiles in the carbonated PC were examined with thermogravimetric analysis/derivative thermogravimetric analysis. The pre-hydration path was traced with isothermal calorimetry. Experimental results suggested that extension of pre-hydration decreased CO2 uptake, but enhanced the extent of PC hydration at 28 days. It was found that a pre-hydration beyond the late deceleration period of PC hydration (where heat generation is slowing down) led to a higher hydrate content of cement paste, hence forming a higher compressive strength of mortar compared to the noncarbonated benchmarks at 28 days. The lesser carbonation-induced water loss and the nucleation seeding enabled by calcium carbonate are likely responsible for this effect. Furthermore, the finding reported here should be useful for fine tuning PC carbonation process for CO2 sequestration in concrete.
- Research Organization:
- Univ. of Michigan, Ann Arbor, MI (United States)
- Sponsoring Organization:
- USDOE; National Energy Technology Laboratory (NETL)
- Grant/Contract Number:
- FE0030684
- OSTI ID:
- 1990025
- Journal Information:
- ACS Sustainable Chemistry & Engineering, Vol. 6, Issue 12; ISSN 2168-0485
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Development of reactive MgO-based Engineered Cementitious Composite (ECC) through accelerated carbonation curing
Supercritical, liquid, and gas CO