Temperature and duration impact on the strength development of geopolymerized granulated blast furnace slag for usage as a construction material
- Authors: Arulrajah, Arul , Maghool, Farshid , Yaghoubi, Mohammadjavad , Phetchuay, Chayakrit , Horpibulsuk, Suksun
- Date: 2021
- Type: Text , Journal article
- Relation: Journal of Materials in Civil Engineering Vol. 33, no. 2 (2021), p.
- Full Text: false
- Reviewed:
- Description: Through the process of extracting iron from iron ore, a by-product is generated known as granulated blast furnace slag (GBFS). Traditional stabilization methods such as cement stabilization are not entirely sustainable options. This research investigates the engineering properties of geopolymer-stabilized GBFS and their viability for usage as a construction material. A combination of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) was used as the liquid alkaline activator (L) along with low-carbon pozzolanic binders, namely, fly ash (FA) and slag (S). The L was prepared with a Na2SiO3:NaOH ratio of 70 30 and binders were added up to 30%. The effect of different curing regimes on the strength of geopolymerized GBFS was evaluated using scanning electron microscopy (SEM) and unconfined compressive strength (UCS) tests. The effect of both the temperature and duration of curing had a vital role in the strength development of the mixtures. The test results indicated that the combination of FA+S as a geopolymer binder could perform better than FA or S alone. With the lowest UCS value of 7.8 MPa and highest value of 43 MPa, all the geopolymer-stabilized GBFS were found to be suitable for a variety of civil and construction applications. © 2020 American Society of Civil Engineers.
Shear strength properties and stress–strain behavior of waste foundry sand
- Authors: Yaghoubi, Ehsan , Arulrajah, Arul , Yaghoubi, Mohammadjavad , Horpibulsuk, Suksun
- Date: 2020
- Type: Text , Journal article
- Relation: Construction and Building Materials Vol. 249, (2020)
- Full Text: false
- Reviewed:
- Description: This research evaluates the engineering properties of waste foundry sand (WFS) as a sustainable construction material. In this research study, extensive laboratory experiments, including X-ray fluorescence (XRF), pH value, particle size distribution, California bearing ratio (CBR) and consolidated drained (CD) direct shear and CD triaxial tests were conducted. In addition, for the comparison purpose, a similar testing program was applied to a control material, namely sand sized waste recycled glass (RG), which is an accepted construction material for geotechnical and pavement construction projects. Results indicated that although the strength properties of WFS were lower than those of RG, the WFS could meet the required characteristics to be used in applications such as engineering fill and road embankments. The outcomes of this research aim to increase the market demand for WFS as a solid waste by improving the construction industry's confidence in its performance. Using WFS as an alternative to natural sands in the construction activities can potentially have significant positive environmental impacts through reducing CO2 emission, as well as preventing the expansion of landfills for the disposal of WFS. © 2020 Elsevier Ltd
Utilisation of alkaline activated industrial by-products in deep soil mixing
- Authors: Yaghoubi, Mohammadjavad , Arulrajah, Ar , Disfani, Mahdi , Horpibulsuk, Suksun , Bo, Myint , Leong, Melvyn
- Date: 2017
- Type: Text , Conference paper
- Relation: Seventh International Conference on Geotechnique, Construction Materials and Environment, Nov. 21-24, 2017, ISBN: C3051, Mie, Japan p. 96-101
- Full Text:
- Reviewed:
- Description: The use of deep soil mixing (DSM) technique in deep ground improvement projects has increased over the past decade due to being more cost-effective and easier to implement compared to other techniques such as piling, for structures subject to low to medium loads. Currently, Portland cement, lime and their combination are being used as the most common binders in DSM. However, due to the economic and concerning environmental disadvantages of using these binders, there is a need for new environmentally friendly cementing materials. This research attempts to find a way to use stockpiles of industrial by-products, such as fly ash (FA) and slag (S), as new green binders; consequently, reducing the carbon footprint in ground improvement projects. Different contents of FA and S, activated by liquid alkaline activator (L), were added to a soft marine soil to evaluate the changes in its behaviour as well as its microstructure. In addition, mixtures with cement (C), lime (Li) and their combination were prepared and tested for comparison. Binders were added at contents of 10, 20 and 30%, by dry soil mass, and samples were cured for 7 days. The results revealed that these new binders significantly increased the strength and stiffness of the soft soil, and they can be a suitable replacement for C and Li. The optimum mixture was found to be CIS+5% FA+15% S, within the range of binder, L and water content studied in this research. Moreover, recycling FA and S would substantially limit the expansion of landfill sites.
Converting optimum compaction properties of fine-grained soils between rational energy levels
- Authors: Soltani, Amin , Azimi, Mahdieh , O'Kelly, Brendan , Horpibulsuk, Suksun
- Date: 2023
- Type: Text , Journal article
- Relation: Transportation Geotechnics Vol. 42, no. (2023), p.
- Full Text:
- Reviewed:
- Description: This study introduces a practical energy conversion (EC)-type modeling framework capable of converting the optimum compaction properties of fine-grained soils between any two rational compaction energy levels (CELs). Model development/calibration was carried out using a database of 242 compaction test results — the largest and most diverse database of its kind, to date, entailing 76 fine-grained soils (covering liquid limits of 16–256%), with each soil tested for at least three different CELs. On establishing the framework, an independent database of 91 compaction test results (consisting of 34 fine-grained soils tested for varying CELs) was employed for its validation. The proposed EC-based models employ measured optimum water content (OWC) and maximum dry unit weight (MDUW) values obtained for a rational CEL (preferably standard Proctor) to predict the same for higher and/or lower compactive efforts (covering 214–5416 kJ/m3). The 95% lower and upper statistical agreement limits between the predicted/converted and measured OWCs were obtained as