Evaluation on the Mechanical Properties of Ground Granulated Blast Slag (GGBS) and Fly Ash Stabilized Soil via Geopolymer Process

• Published in: Materials 2021-05, Vol.14 (11), p.2833
• Main Authors: Abdila, Syafiadi Rizki, Abdullah, Mohd Mustafa Al Bakri, Ahmad, Romisuhani, Rahim, Shayfull Zamree Abd, Rychta, Małgorzata, Wnuk, Izabela, Nabiałek, Marcin, Muskalski, Krzysztof, Tahir, Muhammad Faheem Mohd, Syafwandi, Isradi, Muhammad, Gucwa, Marek
• Format: Article
• Language: English
• Subjects: Caustic soda; Cement; Chemical reactions; Civil engineering; Civil engineers; Clay soils; Construction standards; Curing; Density; Fly ash; Geotechnical engineering; GGBS; Granulation; Highway construction; Mechanical properties; Moisture content; Particle size; Pavement construction; Pavements; Plastic limit; Polymerization; Roads & highways; Shear strength; Silica; Slag; Sodium; Sodium hydroxide; Sodium silicates; Soil compressibility; Soil compression tests; Soil mechanics; Soil permeability; Soil properties; Soil stabilization; Soil strength; Soil structure; Soils; Spectrum analysis; Stabilization
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma14112833

This study intended to address the problem of damaged (collapsed, cracked and decreased soil strength) road pavement structure built on clay soil due to clay soil properties such as low shear strength, high soil compressibility, low soil permeability, low soil strength, and high soil plasticity. Previous research reported that ground granulated blast slag (GGBS) and fly ash can be used for clay soil stabilizations, but the results of past research indicate that the road pavement construction standards remained unfulfilled, especially in terms of clay’s subgrade soil. Due to this reason, this study is carried out to further investigate soil stabilization using GGBS and fly ash-based geopolymer processes. This study investigates the effects of GGBS and ratios of fly ash (solid) to alkaline activator (liquid) of 1:1, 1.5:1, 2:1, 2.5:1, and 3:1, cured for 1 and 7 days. The molarity of sodium hydroxide (NaOH) and the ratio of sodium silicate (Na2SiO3) to sodium hydroxide (NaOH) was fixed at 10 molar and 2.0 weight ratio. The mechanical properties of the soil stabilization based geopolymer process were tested using an unconfined compression test, while the characterization of soil stabilization was investigated using the plastic limit test, liquid limit test, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that the highest strength obtained was 3.15 MPA with a GGBS to alkaline activator ratio of 1.5 and Na2SiO3 to NaOH ratio of 2.0 at 7 days curing time. These findings are useful in enhancing knowledge in the field of soil stabilization-based geopolymer, especially for applications in pavement construction. In addition, it can be used as a reference for academicians, civil engineers, and geotechnical engineers.