Esayas, Gebreyouhannes (PhD)Abraham, Mitiku2019-05-192023-11-112019-05-192023-11-112019-04http://etd.aau.edu.et/handle/12345678/18268Crushed rock sand is a term used for fine aggregate passed by 4.75mm and retained on 150μm sieve size which are manufacture in quarry. Because of raped booming of construction industry in Ethiopia, Natural River sand increasingly depleted and its method of production was affect our planet. Concrete is the most dominant building material in construction world. From the given produced volume of concrete more than 70% is aggregate. So, therefore the quality of concrete is strongly influenced by aggregate’s physical and mechanical properties. In this research physical properties of aggregates are reviewed, compressive strength of concrete produced from CR sand and River sand were tested to learn the influence of fines content in CR sand on concrete production was investigated. In very beginning, crushed rock sand and river sand sample to be used in concrete mixes were collected from YENCOMAD construction Plc. crushing site and Alem Tena Area River respectively and their physical property were studied. Twenty-four different concrete mix having three different water to cement ratio (0.4, 0.5 and 0.6) and four different fines content (6%, 9%, 12% and 15%) for both river and crushed sand were prepared using sand to aggregate ratio 0.45 and water content 190kg/m3. The slump was range between 50mm to 90mm for both sand. The average compressive strength of crushed stone sand concrete between 20 and 60 Mpa and for river sand concrete ranging between 15 to 50 Mpa. A total of 144 cube was casted for trial and 216 cube were casted as final laboratory test. Conclusion and recommendation were drown based on laboratory result analysis. The test results are compared with the standard requirements and specification. Based on the findings, conclusions are drown and recommendations are forwarded.en-USaggregatecompressive strengthconcreteCrushed rockriver sandThesis