Evaluation of Kunkur Fines for Utilization in the Production of Ternary Blended Cements

Victor Kiptoo Mutai, Joseph Mwiti Marangu, Cyprian Muturia M’Thiruaine and Luca Valentini ()
Additional contact information
Victor Kiptoo Mutai: Department of Physical Sciences, Meru University of Science & Technology, Meru 60200, Kenya
Joseph Mwiti Marangu: Department of Physical Sciences, Meru University of Science & Technology, Meru 60200, Kenya
Cyprian Muturia M’Thiruaine: Department of Physical Sciences, Meru University of Science & Technology, Meru 60200, Kenya
Luca Valentini: Department of Geosciences, University of Padua, 35126 Padova, Italy

Sustainability, 2023, vol. 15, issue 23, 1-13

Abstract: Ternary blended cements, such as limestone calcined clay cement (LC 3 ), represent a type of strategic binder for the mitigation of environmental impacts associated with cement production. These are estimated to reduce CO 2 emissions by about 40% compared to ordinary Portland cement (OPC). In this paper, we explore the possibility of producing such ternary blends by utilizing secondary raw materials that may be locally available. Specifically, the primary limestone that is commonly used in LC 3 is herein substituted with quarry dust obtained by sourcing “kunkur”, a carbonate-rich sedimentary rock (also known as caliche) that can be locally utilized for the production of ordinary OPC clinker. To optimize the blending proportions of ternary cement consisting of OPC, calcined clay, and kunkur fines, a “design of experiment” (DoE) approach was implemented with the goal of exploring the possibility of reducing the amount of the OPC fraction to values lower than 50%. The properties of the formulated blends were assessed by a combination of techniques that comprise mechanical strength testing, XRD time-dependent quantitative phase analysis, and SEM–EDS microstructural and microchemical analyses. The results suggest that ternary blended cement based on kunkur fines forms hydration products, such as hemicarboaluminates, which are also observed in LC 3 . This shows that such waste materials can potentially be used in sustainable cement blends; however, the presence of kaolinite in the kunkur fines seems to affect their strength development when compared to both OPC and conventional LC 3 .

Keywords: kunkur fines; blended cement; mixture design; circular economy; design of experiment; supplementary cementitious materials; filler materials (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2023
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/15/23/16453/pdf (application/pdf)
https://www.mdpi.com/2071-1050/15/23/16453/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:15:y:2023:i:23:p:16453-:d:1291674

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().