Fine Aggregate Production and its Environmental Impact in some Selected Sites of the Rift Valley Area in Ethiopia

Yusuf, Yasmin (2014) Fine Aggregate Production and its Environmental Impact in some Selected Sites of the Rift Valley Area in Ethiopia. Masters thesis, Addis Ababa University.

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Abstract

In today‟s world the use of natural aggregate has increased extensively. We live our lives dependent on an infrastructure created out of concrete. Concrete is a composite material of which 60-75% by volume is aggregates. Out of this volume, 30-40% is constituted by fine aggregates. Although potential sources of fine aggregates are widespread and large, land-use choices, economic considerations, and environmental concerns may limit their availability. Making aggregate resources available for our country‟s increasing demand will be an ongoing challenge. Understanding how fine aggregates are produced and what environmental impacts they bring about is an important point to investigate. With this in mind, this research has been undertaken to assess the production process of fine aggregates in some sites of the Oromia region in Ethiopia and the environmental impacts concerned with them. It concentrates on both the positive and negative impacts of sand mining. Positive in terms of financial gain and provision of building material; and negative in terms of the environmental impact it brings about. The production of fine aggregate is not the extraction of the mineral from the source alone but basically involves a number of steps starting from the exploration, mining, processing, transporting and finally reclamation. A visit to three different sites was made along with interviews. From the site visits, it has been found that exploration process has not been undertaken in all of the sites. In all the three sites the mining process used is the artisanal technique which does not employ any machineries but mining is carried out by human labor - making use of hand shovels. In other countries, the sand goes into various combinations of washers, driers, screens, and classifiers to segregate particle sizes, crushers to reduce oversized material, and storage and loading facilities. None of this has been seen in the sites visited. Transportation in all the sites was carried out by making use of a domestic animal - a donkey to an all-weather road and then transported using a dump truck. Even though all the three visited sites are currently active, it has been understood from interviews that reclamation is not normally done for sites which have been closed down. The research further showed that the environmental impacts associated with sand mining are impact on the Riparian Habitat, Flora and Fauna, land degradation, loss of aesthetic value, loss of the stability of the structures, the decrease in water as well as the air quality, damage to roads, the use of unplanned access roads damaging the farm lands damaging their crop, diversion of the canal and, siltation in the downstream areas, i.e. the Awash basin. Moreover, samples from the visited sites were taken and tests were conducted for silt content and gradation. The results have displayed that none of the samples have passed for quality requirements set by the standards for silt and gradation. The production capacity of the workers in all the three sites is minimal and sales price at the sites is somewhat fair but extremely high when it comes to sales in kality area. Moreover, the production of fine aggregates in the rift valley area of Ethiopia is still in the primitive stage. It does not coincide with the standards with respect to production process, quality, and production capacity. The environmental impacts that fine aggregate production bring about are hardly known in this country.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Concrete, Environment, Exploration, Fine aggregate, Impact, Mining,Processing, Production, Reclamation, Transportation, Quality
Subjects:	Q Science > QE Geology T Technology > TA Engineering (General). Civil engineering (General) T Technology > TD Environmental technology. Sanitary engineering T Technology > TN Mining engineering. Metallurgy
Divisions:	Africana
Depositing User:	Andriamparany Edilbert RANOARIVONY
Date Deposited:	04 Jul 2018 10:10
Last Modified:	04 Jul 2018 10:10
URI:	http://thesisbank.jhia.ac.ke/id/eprint/6592

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