High-volume natural volcanic pozzolan and limestone powder as partial replacements for portland cement in self-compacting and sustainable concrete

Abstract
A laboratory study demonstrates that high volume, 45% by mass replacement of portland cement (OPC) with 30% finely-ground basaltic ash from Saudi Arabia (NP) and 15% limestone powder (LS) produces concrete with good workability, high 28-day compressive strength (39 MPa), excellent one year strength (57 MPa), and very high resistance to chloride penetration. Conventional OPC is produced by intergrinding 95% portland clinker and 5% gypsum, and its clinker factor (CF) thus equals 0.95. With 30% NP and 15% LS portland clinker replacement, the CF of the blended ternary PC equals 0.52 so that 48% CO2 emissions could be avoided, while enhancing strength development and durability in the resulting self-compacting concrete (SCC). Petrographic and scanning electron microscopy (SEM) investigations of the crushed NP and finely-ground NP in the concretes provide new insights into the heterogeneous fine-scale cementitious hydration products associated with basaltic ash-portland cement reactions. © 2013 Published by Elsevier Ltd.

Citation
Celik, K., Jackson, M. D., Mancio, M., Meral, C., Emwas, A.-H., Mehta, P. K., & Monteiro, P. J. M. (2014). High-volume natural volcanic pozzolan and limestone powder as partial replacements for portland cement in self-compacting and sustainable concrete. Cement and Concrete Composites, 45, 136–147. doi:10.1016/j.cemconcomp.2013.09.003

Acknowledgements
We thank Super Burkani Blocks for providing crushed and finely-ground basaltic volcanic ash. This research was funded in part by Award No. KUS-l1-004021, from King Abdullah University of Science and Technology (KAUST). Mr. Timothy Teague provided valuable laboratory assistance.

Publisher
Elsevier BV

Journal
Cement and Concrete Composites

DOI
10.1016/j.cemconcomp.2013.09.003

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