Cyclic behaviour of clay stabilised with fly-ash based geopolymer incorporating ground granulated slag

Abdullah, Hayder H.; Shahin, Mohamed A.; Walske, Megan L.; Karrech, Ali

doi:10.1016/j.trgeo.2020.100430

Cited by 34 publications

(19 citation statements)

References 31 publications

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“…Results from the CU tests demonstrated that the addition of geopolymer changed the initial characteristics of remolded clays from quasi-overconsolidated to heavily over-consolidated, rendering high yield surface and more effective shear strength parameters (i.e., cohesion and friction angle). Moreover, although the overall qualitative stress-strain and stress path responses of the clays were similar, significant quantitative differences were observed, particularly in terms of the attainable yield strength, stiffness, and shear strength [91].…”

Section: Shear Strengthmentioning

confidence: 89%

“…According to Cristelo et al [15], curing conditions (i.e., temperature, and curing age) also affects the volume of reaction products and the level of strength improvement of the stabilized soils. Clay mineralogy also plays a vital role in the level of strength improvement using geopolymer as a result of the interaction between the minerals like (kaolinite, illite or montmorillonite) and the chemicals [91].…”

Section: Compressive Strengthmentioning

confidence: 99%

“…Shear resistance of a soil is a function of friction and interlocking of particles, which helps to resist imposed load from the super-structure. Shear behavior of geopolymer-stabilized soils is a field that has not been given much attention beyond the routine UCS testing, which has limited utility in the realistic prediction of load-deformation responses due to lack of control on the drainage conditions or ability to examine the impact of confining pressure [91].…”

Section: Shear Strengthmentioning

confidence: 99%

“…Abdullah et al [91] investigated the Consolidated Undrained (CU) triaxial behavior of a fly ash-based geopolymerstabilized clay at ambient temperature incorporating granulated slag. A 14 M NaOH solution was synthesized with the blended pozzolans (fly ash and slag) and used to stabilize the untreated clay.…”

Section: Shear Strengthmentioning

confidence: 99%

“…It was claimed that these holes were formed by leaching silica and alumina from the surface of the activated fly ash. The partially reacted fly ash particles and cementitious products within the treated soil are believed to serve as nucleation sites that bond clay plates into clusters, thus modifying the structure of the soil and enhancing its mechanical response [91].…”

Section: Microstructurementioning

confidence: 99%

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A Critical Appraisal of Soil Stabilization Using Geopolymers: The Past, Present and Future

Disu

Kolay

2021

Int. J. of Geosynth. and Ground Eng.

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Soft and highly compressible soils beneath civil engineering structures are often responsible for severe problems such as excessive settlement, cracking, sinking, etc. Over the years, these soft soils have been stabilized with Ordinary Portland Cement (OPC). Unfortunately, a known demerit of OPC as a traditional stabilizer is its energy-intensive nature and emission of large quantities of CO 2, which has immediate-and long-term detrimental effects to the environment. This shortcoming has led to the emergence of geopolymers as a viable alternative to OPC with desirable properties such as high strength, stiffness, reduced shrinkage, and low energy consumption. This paper presents a critical appraisal (including a statistical approach) of geopolymer-stabilized soils, from relevant published literature sources covering various soil types and industrial by-products as activators for geopolymers. A review of 50 selected references on geopolymer-stabilized soil revealed that a maximum Unconfined Compressive Strength (UCS) of 82.5 MPa at an elevated temperature of 150 °C and a minimum UCS of 0.38 MPa at room temperature (23 °C) were obtained. The molarity of the alkali precursors (NaOH, KOH, Na 2 SiO 3 , Ca(OH) 2 ) used by different researchers ranged from 1.7 to 23.0 M, while the stabilized soil types ranged predominantly from silty to lateritic clays. From the statistical analysis performed on 50 selected references, a statistically significant difference between molarity, curing temperature, and UCS was observed; while, there was a statistical correlation of 0.539 obtained between UCS and curing temperature. Furthermore, a regression equation was developed to predict the UCS of geopolymer-stabilized soil. However, a major limitation affecting the wide utilization of geopolymers in soil stabilization is the absence of design templates compared to the well-established OPC or lime stabilization parameters. Future research should focus more on long-term durability of geopolymer-stabilized soils, especially wet-dry, freeze-thaw durability, and sustainability assessment.

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Section: Shear Strengthmentioning

confidence: 89%

Section: Compressive Strengthmentioning

confidence: 99%

Section: Shear Strengthmentioning

confidence: 99%

Section: Shear Strengthmentioning

confidence: 99%

Section: Microstructurementioning

confidence: 99%

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