Mechanical Behaviour of Soil Improved by Alkali Activated Binders

Vitale, Enza; Russo, Giacomo; Dell’Agli, Gianfranco; Ferone, Claudio; Bartolomeo, Chiara

doi:10.3390/environments4040080

Cited by 19 publications

(8 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several studies have explored different types of materials such as PKA, GGBS, RHA, PSA, PFA, etc., in obtaining the needed aluminosilicates for geopolymerisation and have proven geopolymers to be highly effective in improving the strength of various soils. However, according to [1,17,27,39], there still exists a huge lump-sidedness between theory and practical engineering applications. The authors believe this gap is largely from cost implications from large scale procurement of alkaline activator compounds, but also from an insufficient database upon which useful post-stabilisation behaviour could at least be inferred under practical conditions.…”

Section: Geopolymer Precursorsmentioning

confidence: 99%

Geopolymers as Alternative Sustainable Binders for Stabilisation of Clays—A Review

et al. 2021

View full text Add to dashboard Cite

The need to transit to greener options in soil stabilisation has revamped research on the use of industrial and agricultural by-products in order to cut down on the current carbon footprint from the use of ordinary Portland cement (OPC) and lime related binders for the treatment of problematic soils. This study is a review on the use of geopolymers constituted by alkali activation of several industrial wastes such as pulverised fuel ash (PFA), ground granulated blast furnace slag (GGBS), metakaolin (MK), glass powder (GP), palm oil fuel ash (POFA), silica fume (SF), rice husk ash (RHA), volcanic ash (VA), and marble powder (MP) for the stabilisation of weak clays. The performance of stabilised clays as subgrade and subbase materials for road pavement construction was evaluated by comparing the 7 day UCS of the treated clays with the strength requirement for stabilised materials as outlined in BS EN 16907-4. The result of the study shows that geopolymers can be employed in improving the engineering properties of problematic clays to meet practical applications. Strength improvement was observed in the stabilised clays with increased precursor content, molarity of alkaline activator, and curing period.

show abstract

Section: Geopolymer Precursorsmentioning

confidence: 99%

Geopolymers as Alternative Sustainable Binders for Stabilisation of Clays—A Review

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The addition of alkali activated stabilizer resulted in reduced volume strains and an overall decrease of compressibility of the treated soil [20]. From an early stage of curing, the geopolymer-soil composite exhibited a deformation modulus two times higher than the untreated samples [6].…”

Section: Introductionmentioning

confidence: 98%

Evaluating Shear Strength of Sand- GGBFS Based Geopolymer Composite Material

Al-Rkaby¹

2019

Acta Polytech

View full text Add to dashboard Cite

Geopolymer has been emerging as a novel and sustainable replacement for the traditional soil improvement materials, such as ordinary Portland cement OPC and lime, which have severe environmental impacts. In this paper, a series of unconfined compression and triaxial tests were conducted on sand and sand - ground granulated blast-furnace slag (GGBFS) based geopolymer. A solution of sodium silicate and sodium hydroxide was employed for the geopolymerization process. Results revealed that adding the GGBFS resulted in a significant increase in the strength properties. This result indicates that geopolymer acted as a cementation agent, providing better bonding between the sand particles and consequently improving the performance of the treated sand.

show abstract

“…Zhang et al [25] used metakaolin-based geopolymer (usually classified as a type of AAC) for shallow soil mixing, and Du et al [1] stabilised a clay soil using lightweight geopolymer. Coudert et al [26] and Vitale et al [27,28] performed a thorough material analysis to study the physico-chemical reaction evolution in soils treated with different Na 2 SiO 3 -activated fly ashes; the latter authors also assessed the one-dimensional compression behaviour of the treated soil samples for different binder contents and curing times. This was related to the chemo-physical evolution of the binders over curing time using X-Ray Diffraction (XRD) analysis.…”

Section: Introductionmentioning

confidence: 99%

A Study of Innovative Alkali-Activated Binders for Soil Stabilisation in the Context of Engineering Sustainability and Circular Economy

et al. 2021

View full text Add to dashboard Cite

In the context of sustainability in the civil engineering industry, chemical ground improvement is becoming increasingly used, as a generally more sustainable alternative to replacing and landfilling unsuitable for construction ground. However, traditional soil stabilisers such as Portland cement or lime are not environmentally impact-free; international research effort is thus focusing on the development of innovative cementing agents. This paper presents results from a feasibility study on the development of suitable alkali-activated slag cements for the stabilisation of two soils. A number of alkali-activators were considered, comprising potassium hydroxide, a range of alkali salts, as well as a material retrieved from waste (Paper Sludge Ash, PSA) which contains free lime. Indicative results of an extensive parametric study in terms of unconfined compressive strength (UCS) are shown, followed by results of ongoing oedometer tests to determine soil compressibility and some preliminary tests on selected soil/binder mixes to observe the durability to wetting-drying cycles. Overall, all alkali-activated cement mixes increased the UCS and stiffness of the soil. Carbonates and Na2SiO3 used on their own gave lower strength increases. The highest strengths were achieved from AAC with KOH and Ca(OH)2 from PSA, which showed similar strength gain. The latter material has shown consistently a lot of promise in terms of strength, stiffness and volumetric stability of the soil as well as treatment durability. Ongoing research focuses on further mix optimisation and a comprehensive mechanical and durability property testing supported by material analysis (mineralogical, chemical and microstructural) to gain a better understanding of the complex mechanisms involved.

show abstract

Mechanical Behaviour of Soil Improved by Alkali Activated Binders

Cited by 19 publications

References 25 publications

Geopolymers as Alternative Sustainable Binders for Stabilisation of Clays—A Review

Geopolymers as Alternative Sustainable Binders for Stabilisation of Clays—A Review

Evaluating Shear Strength of Sand- GGBFS Based Geopolymer Composite Material

A Study of Innovative Alkali-Activated Binders for Soil Stabilisation in the Context of Engineering Sustainability and Circular Economy

Contact Info

Product

Resources

About