TY - JOUR

T1 - Geopolymers Based on Mechanically Activated Fly Ash Blended with Dolomite

AU - Kalinkin, Alexander M.

AU - Gurevich , Basya I.

AU - Kalinkina, Elena V.

AU - Chislov , Mikhail V.

AU - Zvereva , Irina A.

N1 - Publisher Copyright: © 2021 by the authors. Li-censee MDPI, Basel, Switzerland.

PY - 2021/7

Y1 - 2021/7

N2 - This study reports the effect of natural dolomite addition to fly ash and the mechanical activation of this blend on the geopolymerization process. Dolomite was replaced with fly ash at 1, 3, 5, and 10 wt.%. Geopolymers were synthesized at ambient temperature using NaOH solution as an alkaline agent. The geopolymerization process, reactivity of the raw material, compressive strength, and microstructure were studied using X‐ray diffraction, Fourier‐transform infrared spec-troscopy, thermogravimetry, and scanning electron microscopy. It was shown that blending fly ash with dolomite and mechanical activation improved the geopolymer strength, especially during the early age of curing. For geopolymers prepared using a 90% fly ash + 10% dolomite blend cured for 7 d, the strengths were 8.2‐, 2.3‐, and 1.4‐fold higher than those for geopolymers prepared using 100% FA for 30 s, 180 s, and 400 s milling times, respectively. A simple method for evaluating the increments of mechanical activation, carbonate additives, and the synergistic effect in the increase in the compressive strength of the composite geopolymer is proposed.

AB - This study reports the effect of natural dolomite addition to fly ash and the mechanical activation of this blend on the geopolymerization process. Dolomite was replaced with fly ash at 1, 3, 5, and 10 wt.%. Geopolymers were synthesized at ambient temperature using NaOH solution as an alkaline agent. The geopolymerization process, reactivity of the raw material, compressive strength, and microstructure were studied using X‐ray diffraction, Fourier‐transform infrared spec-troscopy, thermogravimetry, and scanning electron microscopy. It was shown that blending fly ash with dolomite and mechanical activation improved the geopolymer strength, especially during the early age of curing. For geopolymers prepared using a 90% fly ash + 10% dolomite blend cured for 7 d, the strengths were 8.2‐, 2.3‐, and 1.4‐fold higher than those for geopolymers prepared using 100% FA for 30 s, 180 s, and 400 s milling times, respectively. A simple method for evaluating the increments of mechanical activation, carbonate additives, and the synergistic effect in the increase in the compressive strength of the composite geopolymer is proposed.

KW - термический анализ

KW - калориметрия

KW - полимеризация

KW - Fly ash

KW - Geopolymers

KW - Mechanical activation

KW - Natural dolomite

KW - mechanical activation

KW - natural dolomite

KW - CALCIUM

KW - fly ash

KW - STRENGTH

KW - LIMESTONE

KW - geopolymers

UR - http://www.scopus.com/inward/record.url?scp=85108814632&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/aae1cb94-0e60-3175-9d20-951be0e89e40/

U2 - 10.3390/min11070700

DO - 10.3390/min11070700

M3 - Article

VL - 11

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 7

M1 - 700

ER -