Potential Use of Rice Husk Ash as Woreta Expansive Soil Stabilizer
| dc.contributor.advisor | Samuel, Tadesse (PhD) | |
| dc.contributor.author | Chalachew, Admas | |
| dc.date.accessioned | 2021-03-30T08:57:54Z | |
| dc.date.accessioned | 2023-11-11T12:51:19Z | |
| dc.date.available | 2021-03-30T08:57:54Z | |
| dc.date.available | 2023-11-11T12:51:19Z | |
| dc.date.issued | 2020-12 | |
| dc.description.abstract | Expansive soils cause serious problem in the civil engineering practice due to swell and shrinkage upon wetting and drying. In Woreta this soil is the dominant and extends to very deep depth. In this study, the potential use and the effectiveness of expansive soils stabilization using rice husk ash are evaluated. Rice husk ash is the most locally available agricultural waste material in Woreta and it is an attractive pozzolanic. According to the chemical content test the main component of the rice husk ash is silica and its amount is about 76%, which is the element that governs the reactivity of the ash. The effectiveness of this ash in soil stabilization is tested in the laboratory by conducting laboratory tests like compaction, California bearing ratio, unconfined compressive strength, Atterberg limit, specific gravity, and free swell on uncured and 7 days cured samples with a different percentage of ash (5%, 10%, 15% and 20% of soil dry weight) with and without the amendment of 4% lime. The results obtained, indicates that the use of rice husk ash in soil stabilization generally increase strength and decrease swelling potentials. The liquid limit, plasticity index, maximum dry density, specific gravity, and free Swell properties had been decreased with the addition of rice husk ash, while the OMC increased. The UCS test results indicated that the treated soil increases by 23% and 67% for uncured and by 49% and 119% for 7 days cured sample in strength over that of the virgin soil with the addition of 5% and 10% rice husk ash respectively. Also, the combination of rice husk ash with 4% lime enormously increase the UCS value for both cured and uncured samples. Others parameters found to be improved are the CBR value and it increased from 1.2% to a maximum of 2% for uncured and 2.4% for 7 days cured with the addition of 10% rice husk ash alone and around 17% for uncured and 22% for 7 days cured with the addition of 10% rice husk ash amended with 4% lime. Nonetheless, both the UCS and CBR of treated expansive soil reduced slightly when the rice husk ash content was greater than 10%, which indicates that the optimum amount to achieve the highest strength is around 10% rice husk ash content. Both UCS and CBR values increase significantly due to the presence of curing. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/25782 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Expansive Soil Stabilizer | en_US |
| dc.subject | Rice Husk | en_US |
| dc.subject | Woreta | en_US |
| dc.title | Potential Use of Rice Husk Ash as Woreta Expansive Soil Stabilizer | en_US |
| dc.type | Thesis | en_US |