Tamang, Pratistha;
(2023)
Characterisation of the mechanical properties and behaviour of compacted class F fly ash-Portland cement-London clay mixtures.
Doctoral thesis (Ph.D), UCL (University College London).
Abstract
In recent years, the use of fly ash (FA), a waste product from coal-fired power plants, for the strength improvement of soils, has received much attention as an alternative to conventional chemical additives like cement. Despite several studies undertaken on the utilisation of FA in soil strength improvement, only a limited amount of advanced experimental data for FA treated soils is available, limiting its application. For a wider range of engineering applications of FA treated soil, such as dams, canals, embankments, etc., advanced laboratory testing and constitutive behaviour understanding are required. This research is aimed at establishing the constitutive behaviour of the FA treated London clay through advanced laboratory testing and constitutive modelling. This is achieved by identifying the effect of FA dosage, compaction conditions and curing period on the behavioural characteristics of the treated soil. Scanning electron microscopy, energy dispersive spectroscopy, isotropic compression, consolidated undrained and drained triaxial tests of the FA treated London clay were performed and the subsequent calibration of a kinematic hardening constitutive model was conducted to obtain conclusions about the behaviour and the calibrated parameters under the different conditions of the tested samples. The laboratory tests allowed us to identify both the qualitative and quantitative effects of the variables studied on the behaviour of the FA treated clay, which is needed to understand the changes required for the modelling of the treated soil. The S3-SKH constitutive model successfully reproduces the important features including the strain-softening due to the destructuration observed in these treated soil specimens. Quantitatively, simulated peak and residual strains were within 10% in analyses simulating consolidated undrained and drained tests, showing a rational basis for implementing such constitutive models for the analysis of FA treated soils in practical applications and designs.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Characterisation of the mechanical properties and behaviour of compacted class F fly ash-Portland cement-London clay mixtures |
| Language: | English |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Civil, Environ and Geomatic Eng |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10171962 |
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