Study on Ready-mixed Concrete Quality Control Practice in Addis Ababa
| dc.contributor.advisor | Abebe, Dinku (Prof.) | |
| dc.contributor.advisor | Derese, Birbirsa (Mr.) Co-Advisor | |
| dc.contributor.author | Mihiretab, Achiso | |
| dc.date.accessioned | 2021-11-15T06:48:21Z | |
| dc.date.accessioned | 2023-11-11T08:29:36Z | |
| dc.date.available | 2021-11-15T06:48:21Z | |
| dc.date.available | 2023-11-11T08:29:36Z | |
| dc.date.issued | 2021-11 | |
| dc.description.abstract | Ready-mixed concrete is the basic construction material used in large quantities for construction purpose all around the world. With enlarged focus on infrastructure and housing activities, use of concrete in several forms are growing from time to time. Concrete that is batched in a controlled environment at a central plant instead of being mixed on the job site which is called ready-mixed concrete brought better option for such a developing demand. Quality control is all the measures that are taken during material selection, concrete production processes and on finished concrete products to ensure the compliance of works with the specification. Concrete structures fail before meeting the required service life due to lack of proper quality control. This research is done on Ready-mixed Concrete Quality Control Practice in Addis Ababa. The objective of this research was to investigate ready-mixed concrete quality in general and to identify main factors hindering quality control in particular. The research was carried out by thoroughly reviewing previous studies, desk study done by collecting concrete test results from third party laboratories, interviewing regulatory bodies, structured and open-ended questionnaire distributed to ready-mixed concrete producers and detailed observation of batching plants and concrete casting sites. From the study it is observed that lack of periodic calibration of batching plants and machines, lack of regular maintenance of batching plants and equipment, and improper batch plant arrangement (general location) were found to be the major factors affecting ready-mixed concrete quality control practice. In addition, improper raw material storage location, age of batching plant, incompetence of the batch manager has also their own impact on ready-mixed concrete quality. As per the evaluation of the test results, based on compliance criteria of Ethiopian standards (EBCS-2:1995) 60% of the lots found to be defective where as 40% of samples are non-defective. Based on compliance criteria of ACI 318, the result show that, the number of defective lots goes down to 47.6 % and that of non-defective goes to 52.4%. Shewhart Chart was used to evaluate the process of ready-mixed concrete quality control and showed that the RMC quality control practice is poor. Generally, the quality control practice of RMC in Addis Ababa is not properly implemented and as a result the expected strength of the concrete is not gained. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/28647 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Batching Plants | en_US |
| dc.subject | Quality | en_US |
| dc.subject | Quality Control | en_US |
| dc.subject | Ready-mixed Concrete | en_US |
| dc.title | Study on Ready-mixed Concrete Quality Control Practice in Addis Ababa | en_US |
| dc.type | Thesis | en_US |