TY - JOUR
T1 - Lime-activated one-part geopolymer mortars from construction, demolition and industrial wastes
AU - Kogbara, Reginald B.
AU - Al-Zubi, Abdelrahman
AU - Mortada, Youssef
AU - Hammoud, Ahmad
AU - Masad, Eyad A.
AU - Khraisheh, Marwan K.
N1 - Publisher Copyright:
© 2023 The Authors
PY - 2024/3
Y1 - 2024/3
N2 - This work focused on the production of one-part geopolymer mortars from construction and demolition wastes (CDW) blended with steel slag. Previous related studies on geopolymer production from CDW utilized conventional two-part geopolymers comprised of highly alkaline activator solutions and CDW materials. Thus, the study's significance consists in producing high-strength (≥35 MPa) ambient-cured mortars from CDW with predominantly concrete waste by replacing conventional highly alkaline activator solutions with an environmentally-friendly alkaline activator, Ca(OH)2 powder. Four mortar mixtures were produced with CDW contents ranging from 50 to 65 % dry weight, varying the brick waste content from 3 to 18 %. The effect of elevated temperature (40 °C) curing was also considered. The results showed that 55 % CDW content had optimum performance across all parameters studied such as compressive and flexural strengths, setting time, as well as changes in nuclear magnetic resonance (NMR)-determined pore structure (porosity and mean pore size) and x-ray diffraction (XRD)-determined degree of crystallinity over time. It had 28-day compressive and flexural strengths of 42 and 5.8 MPa, respectively, and initial and final setting times of 25 and 50 min. The importance of sufficient brick waste content in the geopolymer mixtures for effective mechanical performance is highlighted. The inclusion of concrete waste in powder form reduced compressive strength under ambient curing but improved performance at 40 °C curing. It is concluded that sustainable structural mortars can be produced by ‘just adding water’ to an optimized CDW mixture with predominantly concrete waste blended with brick waste and slag and activated by powdered Ca(OH)2.
AB - This work focused on the production of one-part geopolymer mortars from construction and demolition wastes (CDW) blended with steel slag. Previous related studies on geopolymer production from CDW utilized conventional two-part geopolymers comprised of highly alkaline activator solutions and CDW materials. Thus, the study's significance consists in producing high-strength (≥35 MPa) ambient-cured mortars from CDW with predominantly concrete waste by replacing conventional highly alkaline activator solutions with an environmentally-friendly alkaline activator, Ca(OH)2 powder. Four mortar mixtures were produced with CDW contents ranging from 50 to 65 % dry weight, varying the brick waste content from 3 to 18 %. The effect of elevated temperature (40 °C) curing was also considered. The results showed that 55 % CDW content had optimum performance across all parameters studied such as compressive and flexural strengths, setting time, as well as changes in nuclear magnetic resonance (NMR)-determined pore structure (porosity and mean pore size) and x-ray diffraction (XRD)-determined degree of crystallinity over time. It had 28-day compressive and flexural strengths of 42 and 5.8 MPa, respectively, and initial and final setting times of 25 and 50 min. The importance of sufficient brick waste content in the geopolymer mixtures for effective mechanical performance is highlighted. The inclusion of concrete waste in powder form reduced compressive strength under ambient curing but improved performance at 40 °C curing. It is concluded that sustainable structural mortars can be produced by ‘just adding water’ to an optimized CDW mixture with predominantly concrete waste blended with brick waste and slag and activated by powdered Ca(OH)2.
KW - Alkali activated mortar
KW - Brick waste
KW - Concrete waste
KW - Degree of crystallinity
KW - Proton nuclear magnetic resonance
UR - http://www.scopus.com/inward/record.url?scp=85181719262&partnerID=8YFLogxK
U2 - 10.1016/j.rineng.2023.101739
DO - 10.1016/j.rineng.2023.101739
M3 - Article
AN - SCOPUS:85181719262
SN - 2590-1230
VL - 21
JO - Results in Engineering
JF - Results in Engineering
M1 - 101739
ER -