Currently the Ethiopia construction industries are developing rapidly from time to time and concrete is widely used construction material for different structural works like buildings. Because concrete is economical due to locally availability of raw materials and less demanding of technology and professionals. In concrete production process; aggregates are the most constituents by volume and weight that have a great influence on concrete properties. So proper care should be taken during selection and handling of aggregates, and also during designing and mixing of concrete. An increase of aggregate demands to achieve the requirements of the booming construction causes reduction of nonrenewable natural resources. On the other hand, improper management of demolished concrete wastes faces the industry. Therefore, it is important to recycle concrete wastes to use as a raw material for new concrete production process. In addition to that scoria is a highly available and less cost material in Bahir Dar. The study was planned to investigate physical properties of scoria and recycled concrete aggregates experimentally to use it for sand replacement for concrete production and also to investigate their effects on compressive strength and workability of concrete. In addition, for a river sand replacement the percentage proportion of these materials was examined. The cost of the concrete also computed to analyze its economic feasibility. ASTM standards and ACI 211.1 were applied to conduct physical tests of materials and designing of concrete mix respectively. Based on this the results meet with the specifications. The concrete mix design has been prepared for specified C-25 concrete grade. The 0%, 20%, 40%, 60%, 80%, 100% ratios of recycled concrete aggregate and scoria blended equally were considered for the replacement of sand. Slumps and compressive strength of concrete were determined. Once used Recycled concrete blended with Scoria aggregates as river sand replacement in new concrete, it is possible to produce 25MPa compressive strength up to 40% replacement rate at 28 days. Generally the outcome of this paper is important to give information for using of locally available alternative concrete materials and will be an input for further investigations.