TY - JOUR

T1 - Effect of Waste Concrete Powder Content and Microwave Heating Parameters on the Properties of Porous Alkali-Activated Materials from Coal Gangue

AU - Mischinenko, Vasilii

AU - Vasilchenko, Andrey

AU - Lazorenko, Georgy

N1 - Fabrication and performance characterization of coal gangue-based alkali-activated foams was funded by the Ministry of Science and Higher Education of the Russian Federation (Agreement No. 075-15-2022-1111). Characterization of raw materials was supported by the Russian Science Foundation (Grant No. 24-79-10320).

PY - 2024/11

Y1 - 2024/11

N2 - The objective of this research is to fabricate waste-based alkali-activated foams with better properties in a quick time by using energy-efficient techniques such as microwave irradiation. The present study reports the effect of microwave heating parameters, including heating time and output power, on the properties of porous alkali-activated materials (AAMs) that use coal gangue (CG) as a precursor. The effects of concrete waste (CW) content (0–20 wt %) on the performance and microstructure of CG-based AAMs were investigated. Mechanical, thermal, and microstructural investigations were conducted to characterize the obtained materials. The experimental results indicate that the best characteristics of CG-based alkali-activated foams were achieved when microwave power and microwave heating time were 800 W and 10 min, respectively. The foams prepared by adding the waste concrete powder increased stability and showed lower bulk density and thermal conductivity. When the waste concrete powder content was 10 wt %, the CG-based alkali-activated foams showed the best overall performance. At the same time, the mechanical properties of the alkali-activated foams declined only slightly (~9%). The findings of this work provide a basis for further studies on improving the characteristics of CG-based alkali-activated foams due to the physical effect of a microwave field on fresh mortar without the use of a chemical foaming agent while reducing energy consumption in the production process.

AB - The objective of this research is to fabricate waste-based alkali-activated foams with better properties in a quick time by using energy-efficient techniques such as microwave irradiation. The present study reports the effect of microwave heating parameters, including heating time and output power, on the properties of porous alkali-activated materials (AAMs) that use coal gangue (CG) as a precursor. The effects of concrete waste (CW) content (0–20 wt %) on the performance and microstructure of CG-based AAMs were investigated. Mechanical, thermal, and microstructural investigations were conducted to characterize the obtained materials. The experimental results indicate that the best characteristics of CG-based alkali-activated foams were achieved when microwave power and microwave heating time were 800 W and 10 min, respectively. The foams prepared by adding the waste concrete powder increased stability and showed lower bulk density and thermal conductivity. When the waste concrete powder content was 10 wt %, the CG-based alkali-activated foams showed the best overall performance. At the same time, the mechanical properties of the alkali-activated foams declined only slightly (~9%). The findings of this work provide a basis for further studies on improving the characteristics of CG-based alkali-activated foams due to the physical effect of a microwave field on fresh mortar without the use of a chemical foaming agent while reducing energy consumption in the production process.

KW - alkali-activated materials

KW - coal gangue

KW - geopolymer

KW - microwave foaming

KW - mine waste

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85210563113&origin=inward&txGid=b2c0aaefd62a4ef11e5a2db72347b7e4

UR - https://www.mendeley.com/catalogue/04d38fd3-c5fe-3401-aa68-4bf77c6e02c6/

U2 - 10.3390/ma17225670

DO - 10.3390/ma17225670

M3 - Article

C2 - 39597493

VL - 17

JO - Materials

JF - Materials

SN - 1996-1944

IS - 22

M1 - 5670

ER -