TY - JOUR

T1 - Meta-halloysite to improve compactness in iron-rich laterite-based alkali activated materials

AU - Kaze, Cyriaque Rodrigue

AU - Venyite, Paul

AU - Nana, Achile

AU - Juvenal, Deutou Nemaleu

AU - Tchakoute, Herve Kouamo

AU - Rahier, Hubert

AU - Kamseu, Elie

AU - Melo, Uphie Chinje

AU - Leonelli, Cristina

N1 - Funding Information: The authors are grateful to Dr. Mirko Braga and Dr. Pasquale Pansini, from R.S.A. Laboratory, from Ingessil S.r.l. Verona, Italy, for providing the alkaline solutions used in this work. This project also received the contribution of the Academic of Science for the Third World TWAS through the funding 15-079 RG/CHE/AF/AC_I to Dr. Elie Kamseu.

PY - 2020/1/1

Y1 - 2020/1/1

N2 - In this paper, the results of the experimental investigation were used to understand the effect of fine meta-halloysite on the reactivity, mechanical and microstructural properties of laterite-based geopolymers. Laterite was replaced by 0, 20, 30 and 50 wt% of meta-halloysite in order to improve the physico-chemical performance. Meta-halloysite was prepared by calcination of natural halloysite at 600 °C. The moduli (molar ratio SiO2/Na2O) of the activating solutions were 1.04, 0.92, and 0.75 with H2O/Na2O = 9.78, 10.45 and 12.04, respectively. The results indicated that calcined laterite has a high specific surface area (43.00 ± 0.12 m2/g), notwithstanding a high average particle size (d50 = 45.20 μm) compared to meta-halloysite with a smaller average particle size (d50 = 8.40 μm) and a specific surface (29.80 ± 0.16 m2/g). The compressive strength of geopolymers increased upon the addition of meta-halloysite from 12 MPa to 45 MPa at 28 days. While the setting time and water absorption decrease with increase in the of meta-halloysite content as well as with increase in Si/Al, Si/Fe, Al/Fe and Na/Al molar ratios used in the synthesis of geopolymers. The use of fine meta-halloysite resulted in better efficiency and improved mechanical performance of synthesized products.

AB - In this paper, the results of the experimental investigation were used to understand the effect of fine meta-halloysite on the reactivity, mechanical and microstructural properties of laterite-based geopolymers. Laterite was replaced by 0, 20, 30 and 50 wt% of meta-halloysite in order to improve the physico-chemical performance. Meta-halloysite was prepared by calcination of natural halloysite at 600 °C. The moduli (molar ratio SiO2/Na2O) of the activating solutions were 1.04, 0.92, and 0.75 with H2O/Na2O = 9.78, 10.45 and 12.04, respectively. The results indicated that calcined laterite has a high specific surface area (43.00 ± 0.12 m2/g), notwithstanding a high average particle size (d50 = 45.20 μm) compared to meta-halloysite with a smaller average particle size (d50 = 8.40 μm) and a specific surface (29.80 ± 0.16 m2/g). The compressive strength of geopolymers increased upon the addition of meta-halloysite from 12 MPa to 45 MPa at 28 days. While the setting time and water absorption decrease with increase in the of meta-halloysite content as well as with increase in Si/Al, Si/Fe, Al/Fe and Na/Al molar ratios used in the synthesis of geopolymers. The use of fine meta-halloysite resulted in better efficiency and improved mechanical performance of synthesized products.

KW - Efflorescence

KW - Geopolymer composite

KW - Laterite

KW - Mechanical strength

KW - meta-Halloysite

KW - Shrinkage

UR - http://www.scopus.com/inward/record.url?scp=85073369398&partnerID=8YFLogxK

U2 - 10.1016/j.matchemphys.2019.122268

DO - 10.1016/j.matchemphys.2019.122268

M3 - Article

AN - SCOPUS:85073369398

VL - 239

JO - Materials chemistry and physics

JF - Materials chemistry and physics

SN - 0254-0584

M1 - 122268

ER -