Concrete is a material that is composed of 60-80% of aggregates by volume. Natural rncrushed basaltic rock is extensively used in Addis Ababa as a coarse aggregate in concreternproduction. Studies have shown that extensive production of coarse aggregate from naturalrnresources has negative impact on the landscape, water and atmosphere. To alleviate thisrnnegative impact, the experimental research aims to partially replace the basaltic coarsernaggregate with waste crushed clay brick obtained from brick factories located in andrnaround Addis Ababa, in concrete production. rnThe research studied the effect of replacing a C-25 grade concrete coarse aggregate withrncrushed clay brick by 10%, 20%, 30%, 40% and 100% by volume. The effect onrnworkability, hardened density, compressive strength, flexural strength and waterrnpenetration depth were investigated. The clay bricks used as replacements were collectedrnfrom four different brick factories that are found in and around Addis Ababa. rnA total of twenty one concrete mixes were made that include the control and thernreplacement mixes. A water/cement ratio of 0.49 was used for all the mixes. In all thernmixes the crushed clay bricks were used in a saturated surface dry condition. The findingsrnof the experimental study showed that all the crushed clay bricks obtained fromrnrepresentative four different brick factories can be used as partial replacement of coarsernaggregate up to 30% with a water/cement ratio of 0.49. Full replacement of coarsernaggregate with crushed clay brick was made possible with a water/cement ratio of 0.40rnthough that particular concrete mixture was found to be uneconomical compared with thernunit cost of the control mix. rnIt was found that the slump and flexural strength of the replacement mix decreased whenrnthe crushed clay aggregate replacement percentage increased. The hardened density of thernconcrete produced with 30% replacement amount decreased by 3% from the control mix.rnBased on the water penetration test, it was found that the water penetration depth of thernconcrete increased when the CCB aggregate replacement increased. rnThe amount of cost reduced when using 30% of CCB aggregates in replacement ofrncrushed basalt stone is very insignificant only by 0.98% per one meter cube of concrete.