Study on Quality of Site Concrete Production and its Management Practice in Addis Ababa Housing Projects (Case study on Koye Feche housing Projects)
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Date
2017-03
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Addis Ababa University
Abstract
Concrete, because of its versatility in use, is a major component of most of our infrastructural
facilities today. The quality of concrete is affected by its constituent materials, the equipment
used and the workmanship in concrete production process. A better or poor concrete may be
made of exactly the same ingredients based on the quality control practice of the production
process.
The city administration of Addis Ababa is building and administering condominium buildings
around the city for more than one million house seekers around different project location of
Addis Ababa. Most parts of these projects are reinforced concrete structure in which concrete
takes the major proportion among the consumed construction materials.
This research is carried out on the quality of concrete produced and the quality management
practice to enhance concrete quality under projects administered by Addis Ababa housing project
office, by taking the Koye Feche site as a case study. The research used literature review, desk
study, interview with experts and analysis of compressive strength test results on samples
collected from ongoing concrete production sites.
Statistical quality control based on compressive strength tests conducted on selected projects
reveals that, 40.4% of the test results were found to be defective based on EBCS-2:1995
compliance criteria’s. According to ACI-214 classification, 35.4% of test result based on
standard deviation indicates poor quality control whereas 71.25% of the test results show poor
quality control practice based on their coefficient of variations.
The investigation shows that, the use of poor gradation aggregate and high silt, clay, and dust
content of sand, water with impurities, problems with batching which usually called under
batching and over batching are major causes of quality problems. Furthermore, lack of attentive
control on each production process, lack of management commitment and poor workmanship in
quality concrete production is also the most frequent problems identified by respondents.
Key Words: AAHDPO, Coefficient of Variation, CQMP, Management Commitment, Quality
Control, Standard Deviation, Statistical Quality Control, TQM and Workmanship.
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Keywords
AAHDPO, Coefficient of Variation, CQMP, Management Commitment, Quality Control, Standard Deviation, Statistical Quality Control, TQM and Workmanship