Browsing Civil Engineering by Author "Sahu, B.K."
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Sahu, B.K.; Jayaram, S. (University of Botswana, NaN, 2000)[more][less]
Abstract: Alarmingly high accumulation of fly ash has led geochemical engineers into finding a solution for the use of flyash as a construction material in the recent past. As of now, although the material has been used in a limited way in the construction of roads, embarkments,dykes and by cement industries, most of it is still dumped as a waste material. There is a general opinion mongst teh Geochemical engineers that fly ash is a non-hazardous material. However, the authors felt that it may not be entirely true due to the fact that fly ash does contain quite a significant proportion of soluble salts. These salts would leak into water if fly ash comes into contact with water or if the ground water leaked through a bed of fly ash. The investigation revealed that Dissolved Oxygen of fly ash polluted tap and clean water is reduced to a level far below the permissible limit for aquatic life. The author would like to emphasise that the findings of the present investigation are being submitted to open an agenda on the issue of water pollution by the fly ash leachate, may it be ground water, water in the vicinity of the ash being used in the construction of dykes,dams, river training structures or for reclamation on sea shores. URI: http://hdl.handle.net/10311/601 Files in this item: 1
Sahu_BJT_2000.pdf (863.8Kb) -
Sahu, B.K.; Mathur, S.; Kemsley, B. (University of Botswana, NaN, 2004)[more][less]
Abstract: The national road network continues to play a fundamental and catalytic role in the promotion of social and economic development of Botswana. However, a combination of adverse climatic and geological factors, such as scarcity of conventional road building materials, near absence of a non saline surface water, and climatic extremes have dictated the need for innovative engineering approaches to highway design, construction and maintenance. In recent years application of fly ash has been considered in road construction with great interest. Fly ash is a pozzolanic material, which in the presence of water combines with lime to produce a cementetious material with excellent structural properties. Attempts have, therefore, been made at Botswana Roads Department in collaboration with University of Botswana to explore the feasibility of utilizing fly ash alone to improve the physical and strength characteristics of locally available non-standard marginal materials. The results indicate that with the addition of fly ash plasticity dereases while California Bearing Ration (CBR) increases for calcrete and other locally available marginal materials for road construction. With appropriate amount of fly ash and an adequate curing the material can be improved to meet the requirement of base and sub-base coarse. URI: http://hdl.handle.net/10311/644 Files in this item: 1
Sahu_BJT_2004.pdf (606.5Kb)
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