Influences of Silica Fume on Compressive Strength and Chemical Resistances of High Calcium Fly Ash-Based Alkali-Activated Mortar

Kantiya Sothornchaiwit, Warayut Dokduea, Weerachart Tangchirapat, Suraparb Keawsawasvong, Chanachai Thongchom and Chai Jaturapitakkul
Additional contact information
Kantiya Sothornchaiwit: Construction Innovations and Future Infrastructures Research Center (CIFIR), Department of Civil Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand
Warayut Dokduea: Construction Innovations and Future Infrastructures Research Center (CIFIR), Department of Civil Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand
Weerachart Tangchirapat: Construction Innovations and Future Infrastructures Research Center (CIFIR), Department of Civil Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand
Suraparb Keawsawasvong: Department of Civil Engineering, Faculty of Engineering, Thammasat School of Engineering, Thammasat University, Pathumthani 12120, Thailand
Chanachai Thongchom: Department of Civil Engineering, Faculty of Engineering, Thammasat School of Engineering, Thammasat University, Pathumthani 12120, Thailand
Chai Jaturapitakkul: Construction Innovations and Future Infrastructures Research Center (CIFIR), Department of Civil Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand

Sustainability, 2022, vol. 14, issue 5, 1-12

Abstract: Although elevated temperature curing can increase the compressive strength of alkali-activated mortar, its field applications are still limited. In this study, alkali-activated mortars were prepared using high calcium fly ash (FA) as a precursor. Small amounts of silica fume were used to partially replace high calcium fly ash at 3–9% by weight to increase the strength of alkali-activated mortar. All mixtures had a liquid to binder ratio of 0.60 and sand to binder ratio of 2.75 by weight. A ratio of NaOH to Na 2 SiO 3 solution was kept at 2:1 by weight. Mortar flow was also held between 105–115 using a superplasticizer. Compressive strength and durability were investigated in terms of acid and sulfate resistance. The effects of silica fume addition and curing temperature on compressive strength were found to be significant. The optimum content of silica fume was 6%, providing compressive strength as high as that of alkali-activated mortars cured at 45 °C. The weight loss of alkali-activated mortar due to sulfuric acid attack decreased with increasing silica fume content and curing temperature. All alkali-activated mortars were found to have a better performance than (ordinary) Portland cement (OPC) mortars and mortars containing 40% FA. Alkali-activated mortars immersed in magnesium sulfate solutions had compressive strength that decreased with an increase in curing temperature. The expansion of alkali-activated mortar due to sodium sulfate attack increased with increasing silica fume content, and the expansion decreased with increased curing temperature. All alkali-activated mortars performed better than OPC mortars after 98 days of sulfate attack.

Keywords: alkali activated mortar; silica fume; magnesium sulfate; sodium sulfate; sulfuric acid (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2022
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/14/5/2652/pdf (application/pdf)
https://www.mdpi.com/2071-1050/14/5/2652/ (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:14:y:2022:i:5:p:2652-:d:757747

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 ().