Properties of high-calcium and low-calcium fly ash combination geopolymer mortar containing recycled aggregate

Peem Nuaklong; Ampol Wongsa; Vanchai Sata; Kornkanok Boonserm; Jay Sanjayan; Prinya Chindaprasirt

doi:10.1016/j.heliyon.2019.e02513

Properties of high-calcium and low-calcium fly ash combination geopolymer mortar containing recycled aggregate

Heliyon. 2019 Sep 30;5(9):e02513. doi: 10.1016/j.heliyon.2019.e02513. eCollection 2019 Sep.

Authors

Peem Nuaklong¹, Ampol Wongsa¹, Vanchai Sata¹, Kornkanok Boonserm², Jay Sanjayan³, Prinya Chindaprasirt^{1

4}

Affiliations

¹ Sustainable Infrastructure Research and Development Center, Department of Civil Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen, 40002, Thailand.
² Department of Applied Chemistry, Faculty of Sciences and Liberal Arts, Rajamangala University of Technology Isan, Nakhon Ratchasima, 30000, Thailand.
³ Centre for Sustainable Infrastructure, Faculty of Science Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia.
⁴ Academy of Science, The Royal Society of Thailand, Dusit, Bangkok, 10300, Thailand.

Abstract

This study presents the properties of a recycled aggregate geopolymer mortar made with a blend of high-calcium fly ash (HCF) and low-calcium fly ash (LCF). An experimental study was divided into two series. In series I, an effort was made to produce a more durable HCF geopolymer by partially replacing a portion of the HCF with LCF. A mortar with a 50:50 weight blend of HCF and LCF provided a high early strength and showed excellent potential in an acidic environment. In series II, recycled aggregate was used in the LCF-blended HCF geopolymer mortar. The results showed that the compressive strength of the geopolymer mortar decreased with an increase in the recycled aggregate content. The results also indicated that application of the mortar made with recycled aggregate under aggressive conditions should be avoided. However, a mixture with 25% recycled aggregate showed a compressive strength similar to that of the control mixture containing 100% natural aggregate.

Keywords: Cement; Cement additive; Civil engineering; Concrete technology; Geopolymer mortar; Green engineering; High-calcium fly ash; Low-calcium fly ash; Materials property; Recycled aggregate; Structural engineering.