A study on solidification of dredged marine soils using cement and bottom ash
Dredged marine soils (DMS) are the sediments and debris removed during the dredging process. In Malaysia, DMS are considered as wastes and are currently not being recycled. Solidification of DMS needs to be undertaken before the materials can be reused. Soil solidification involves the use of solidi...
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| Format: | Thesis |
| Published: |
2015
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/8028/ http://eprints.uthm.edu.my/8028/1/amira_azhar.pdf |
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| Summary: | Dredged marine soils (DMS) are the sediments and debris removed during the
dredging process. In Malaysia, DMS are considered as wastes and are currently not
being recycled. Solidification of DMS needs to be undertaken before the materials can
be reused. Soil solidification involves the use of solidification agents or binders in soft
soils to improve the geotechnical properties. This study focused on the development of
strength of three solidified fme-grained DMS admixed with cement and bottom ash
(BA). The factors that could influence the strength development are curing period
effects, water-binder ratio, percentage of binders and percentage of granular admixture
were examine. The DMS were collected fkom dredge sites in Melaka and Kelantan,
while the binder used were ordinary Portland cement (C) and the granular admixture
bottom ash (BA) retrieved fiom a local coal power plant. The standard unconfined
compression, bender element and synthetic precipitation leaching procedure (SPLP)
test were conducted to determine the improvement of strength, stifihess and leaching
behaviour of solidified DMS. The water-binder ratio used in this study was 1,3 and 5.
The results show the strength and stifl5ess increased with prolonged curing. As for
water-binder ratio, the strength and stiftkess increased when the water-binder ratio
decreased. The results show that, high plasticity clay (CH) samples with water-binder
(wh) ratio =1 has the highest strength that is up to 4.7 MPa. The optimal dosage of BA
or granular admixture for effective solidification of the DMS was found to be 25 %.
With higher BA dosages strength and stiaess of the solidified DMS would increase
till it peaked at the optimal dosage. After exceeding the optimal BA dosage, the
strength was observed to decrease rather dramatically. All of the elements tested using
the SPLP method does not exceed the allowable limit for drinking water. In
conclusion, solidification of DMS with cement-bottom ash improved the original
properties of the DMS, with the added 'green' value of partial substitution of cement
with an industrial waste product. |
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