| Author | Koo, Kean Siang |
| Call Number | AIT Thesis no. GT-90-20 |
| Subject(s) | Fly ash
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of
Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. GT-90-20 |
| Abstract | This study is concerned with the suitability of fly ash as a structural fill
and construction material for roads and embankments. In order to evaluate the
effectiveness of fly ash utilisation, its mineralogical, chemical and engineering
properties need to be determined properly. Collapse of large disposal dumps and
resulting mudflows under heavy rainfall has already raised environmental concerns.
Utilization of fly ash for engineering purposes is both environmentally beneficial
and economically fruitful. Laboratory investigations have been carried out for the
determination of grain size distribution, mineralogy, chemical composition, pozzolanic
activity, compaction and permeability characteristics, CBR, compressive and shear
strengths and the collapse potential of fly ash. It is found that crystalline
minerals are generally non-reactive at ordinary temperatures. The glassy phase
was found predominantly in the fine particles and the unconfined compression tests
have revealed that higher the proportion of glass, greater is the compressive
strength. Moreover, it is discovered that the development of strength or cementation
in reactive products of hydrated fly ash is mainly caused by calcium silicate
hydrate and calcium aluminate hydrate, Gypsum, calcium carbonate and ettringite.
Besides, this low carbon fly ash can be easily compacted to produce acceptable dry
densities over a wide range of water contents. Curing with an adequate moisture
supply plays an important role in accelerating the pozzolanic reactions, hence
improving the time-dependent engineering properties. Furthermore, the compressive
and tensile strengths of pozzolanic fly ash increase with time. This hardening
process is beneficial due to the fact that there is an increase in internal cohesion
as a result of cementation. The results obtained from CBR test reveals its
applicability in the construction of sub-base for roads and runaways. Therefore,
low carbon fly ash with high Cao content is pozzolanic and has a good potential
to be utilized as an effective fill for raising embankments (roads and dams),
airfields, backfill for retaining structures, low cost housing, as well as for the
stabilization of collapsible or compressible soils. |
| Year | 1991 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GT-90-20 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Geotechnical and Transportation Engineering (GT) |
| Chairperson(s) | Indraratna, Buddhima |
| Examination Committee(s) | Prinya Nutalaya, ;Bergado, Dennes T. |
| Scholarship Donor(s) | The ยท Government of Japan ; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1991 |