Utilization of alkali-activated construction demolition waste for sandy soil improvement with large-scale laboratory experiments

• Published in: Construction & building materials Vol. 302; p. 124173
• Main Author: Bagriacik, Baki
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 04-10-2021
• Subjects: Alkali activator; Construction demolition waste; Sandy soil; Soil improvement; Soil improvement; Sandy soil; Alkali activator; Construction demolition waste
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2021.124173

•A large scale experimental setup and measurement system.•An alternative material to cement: Geopolymer.•Production of geopolymer from construction demolition wastes.•The use of geopolymers in soil improvement.•Less CO2 emission than similar materials (eg. cement)•A more economical improvement method.•A sustainable use of construction demolition wastes.
Using alkali-activated materials to treat waste materials is becoming more prevalent in geotechnical engineering. Adding these materials into soil particles as a cementitious material can improve the geotechnical properties of problematic soils, and minimize environmental pollution. The present study focused on the feasibility of using alkali-activated construction demolition waste (CDW) as a stabilizer for large-scale soil improvement applications. The CDW was used as a source of aluminosilicate; sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium oxide (CaO) (at concentrations of 2 M, 6 M, 10 M, and 14 M) were used as the alkaline media. CDW (16%) was selected as the source of alkali-activated material. The optimal concentrations of NaOH, KOH, and CaO were found to be 10 M, 10 M, and 6 M, respectively. Moreover, 21 days and 39 °C yielded the best results at the bearing capacity values. Thus, the use of CDW as an alkali activator is a better remedy for soil engineering properties, and contributes to soil improvement.