| Title |
Evidence of scawtite and tilleyite formation at ambient conditions in hydrated Portland cement blended with freshly-precipitated nano-size calcium carbonate to reduce greenhouse gas emissions |
| ID_Doc |
27029 |
| Authors |
McDonald, LJ; Afzal, W; Glasser, FP |
| Title |
Evidence of scawtite and tilleyite formation at ambient conditions in hydrated Portland cement blended with freshly-precipitated nano-size calcium carbonate to reduce greenhouse gas emissions |
| Year |
2022 |
| Published |
|
| DOI |
10.1016/j.jobe.2021.103906 |
| Abstract |
Activated calcium carbonate (a-CaCO3) is used partially to replace Portland cement. a-CaCO3 is comprised of nanoscale calcium carbonate, in amorphous and calcite forms, and its enhanced carbonate activity converts calcium carbonate from being an inert filler to a reactive component. Its reaction with the C-S-H phase alters the conventional hydrate mineralogy with spontaneous formation at similar to 20?degrees C of scawtite, Ca-7(Si6O18)CO3.2H(2)O and tilleyite, Ca5Si2O7(CO3)(2). Compressive strength measurements show that up to 20 mass% cement replacement by calcium carbonate does not decrease 7-and 28-day compressive strengths compared to a Portland cement benchmark. a-CaCO3 also accelerates the hydration of silicate clinker minerals. Using activated calcium carbonate as a supplementary cementing material enables substantial reduction of CO2 emissions, firstly by capturing part of the CO2 from cement kilns to make nanoscale calcium carbonate and secondly, by using the a-CaCO3 capture product to replace part of the cement. |
| Author Keywords |
Carbon capture and use (CCU); Cement mineralogy; Circular economy; Calcium carbonate; Portland cement |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:000775439700003 |
| WoS Category |
Construction & Building Technology; Engineering, Civil |
| Research Area |
Construction & Building Technology; Engineering |
| PDF |
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