Investigating the Suitability of Partial Replacement of Basalt with Scoria as a Base Course Material for a Flexible Pavement.
This study aims at evaluating the applicability of Scoria gravel as an alternative base course material in flexible pavements through blending with Basalt by modifying the physical and mechanical engineering properties of scoria. They are two types of scoria in Uganda with probably different prop...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Kabale University
2024
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| Subjects: | |
| Online Access: | http://hdl.handle.net/20.500.12493/2283 |
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| Summary: | This study aims at evaluating the applicability of Scoria gravel as an alternative base course material in flexible pavements through blending with Basalt by modifying the physical and mechanical engineering properties of scoria.
They are two types of scoria in Uganda with probably different properties that is black and red Scoria. In this case, Red scoria was used. This scoria was obtained from Kisoro district at the slopes of mt. Muhabura while basalt was obtained from Ntungamo district in Karegyeya. The material was taken to Mukono where it was tested from.
Non-Probabilistic sampling techniques and experimental methods were used. To achieve the objectives of the study, the laboratory tests were passed in three steps. First, the Engineering properties of materials were independently tested; the results proved the marginality of red scoria gravel yet basalt showed suitable physical and mechanical properties. Second, scoria gravel was mechanically and physically stabilized in percentages by weight increments of 5%, 10%, 15%, 20%, 40%, 50%, 60%, 80% and 100%.
The fundamental tests required for the base course CRR class are plasticity index, particle size distribution, flakiness index, linear shrinkage and ten percent fines value according to the general specifications for roads and bridges of Uganda. According to the general specifications for roads and bridges works, (Ministry of Works, Housing and Communicatins, 2005), the minimum requirements for plasticity index, particle size distribution, flakiness index, linear shrinkage and ten percent fines value are non-plastic, within the specified upper and lower limits, below 35% (<35%), below 3% (<3%) and above 110 kN with a ratio of soaked to dry being greater than 75% respectively.
Basalt, scoria and their corresponding percentages satisfied the requirements for plasticity index, linear shrinkage and flakiness index. 5%Scoria-95% Basalt and 10% Scoria-90% Basalt satisfied all the requirements for the base course as per the general specification of roads and bridge works. 15% scoria-85% basalt and 20% scoria-80% basalt did not meet the requirements for ten percent fines value but satisfied all the other requirements for the base course. The remaining percentages failed to meet the requirements for both particle size distribution and ten percent fines value test but passed all the other tests.
The optimum percentage blend was obtained as 10% scoria-90% basalt. Finally, based on this study it was recommended to use scoria gravel as an alternative base course construction material. |
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